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Engine Controls/fuel - 4.3 (lu3) - Diagnostic Information and Procedures Chevrolet Express G3500

Testing & Diagnostics ~55688 words

Diagnostic Instructions

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit/System Description

The engine control module (ECM) uses the crankshaft position sensor and camshaft position sensor information to monitor the correlation between the crankshaft and camshaft position.

Conditions for Running the DTC

  1. DTC P0335, P0336, P0340, P0341, P0641, or P0651 is not set.
  2. The engine is running.
  3. The engine speed is less than 2,000 RPM.

The DTC runs continuously when the above conditions are met.

Conditions for Setting the DTC

The ECM detects that the camshaft position sensor pulses occur more than 11 crank degrees before or 11 crank degrees after the nomal position for 24 out of 30 engine cycles.

Action Taken When the DTC Sets

DTC P0016 is a Type B DTC.

Conditions for Clearing the DTC

DTC P0016 is a Type B DTC.

Reference Information

Description and Operation

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ignition ON.
  2. Verify DTC P0335, P0336, P0340, P0341, P0641, or P0651 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If none of the DTCs are set
  3. Engine Running at normal operating temperature.
  4. Verify DTC P0016 is not set. If the DTC is set Inspect for the following and repair as necessary: The correct installation of the Camshaft Position Sensor. The correct installation of the Crankshaft Position Sensor. A timing chain tensioner condition. An incorrectly installed timing chain. Excessive play in the timing chain or sprockets. A timing chain that jumped teeth. If the DTC is not set
  5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  6. Verify the DTC does not set. If the DTC sets A mechanical condition listed above still exists. If the DTC does not set
  7. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
HO2S Heater Voltage SupplyP0030, P0036, P0050, P0056, P0135, P0138, P0141, P0155, P0158, P0161, *P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0135, P0141, P0155, P0161P0030, P0036, P0050, P0056, P0135, P0141, P0155, P0158, P0160, P0161P0690P0135, P0141, P0155, P0161
HO2S Heater ControlP0030, P0036, P0050, P0056P0053, P0054, P0059, P0060, P0138, P0140, P0158, P0160P0030, P0036, P0050, P0056, P0135, P0141, P0152, P0154, P0155, P0158, P0160, P0161P0030, P0036, P0050, P0056, P0135, P0141, P0151, P0155, P0158, P0160, P0161P0135, P0141, P0155, P0161
* Opens fuse

Typical Scan Tool Data

CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine Running Parameter Normal Range: 0.3-1.5 A
Ignition Voltage0 A0 A0.3-1.5 A
HO2S Heater Low Control0 A0 A0 A

HO2S Bank 1 or 2 Sensor 1 or 2 Heater

The heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. A heating element inside the HO2S minimizes the time required for the sensors to reach operating temperature. Voltage is provided to the heater by an ignition voltage circuit through a fuse. With the engine running, ground is provided to the heater by the HO2S heater low control circuit through a low side driver within the engine control module (ECM). The ECM uses pulse width modulation (PWM) to control the HO2S heater operation to maintain a specific HO2S operating temperature range.

P0030, P0036, P0050, or P0056

  1. The ignition voltage is between 11-32 volts.
  2. The engine speed is greater than 400 RPM.
  3. The DTCs run continuously when the above conditions are met for 1 second.

P0053, P0054, P0059, or P0060

  1. DTCs P0112, P0113, P0117, P0118, or P2610 are not set.
  2. The engine run time is less than 3 seconds.
  3. The ignition voltage is less than 32 volts.
  4. The ignition is OFF for greater than 8 hours.
  5. The engine coolant temperature (ECT) is between -30 to +45°C (-22 to +113°F) at engine start-up.
  6. The ECT and the intake air temperature (IAT) are within 8°C (14°F) at engine start-up.
  7. The DTCs run once per drive cycle when the above conditions are met.

P0135, P0141, P0155, or P0161

  1. DTCs P0116, P0117, P0118, or P0128 are not set.
  2. The ignition 1 voltage is between 10-32 volts.
  3. The HO2S is at operating temperature.
  4. The HO2S is commanded ON.
  5. The DTCs run once per drive cycle when the above conditions are met for 120 seconds.

P0030, P0036, P0050, or P0056

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 7 seconds.

P0053, P0054, P0059, or P0060

The ECM detects the HO2S heater is not within a specified resistance range at engine start-up for greater than 3 seconds.

P0135 or P0155

The ECM detects that the HO2S 1 heater current is greater than 3.1 amps, or less than 0.3 amps for greater than 10 seconds.

P0141 or P0161

The ECM detects that the HO2S 2 heater current is greater than 2.9 amps, or less than 0.3 amps for greater than 10 seconds.

DTCs P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0135, P0141. P0155, and P0161 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0135, P0141. P0155, and P0161 are Type B DTCs.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Engine idling, command the appropriate HO2S heater to 100 % and 0 % with a scan tool while observing the control circuit status parameters listed below. Each parameter should toggle between OK and Not Run or Not Run and OK. HO2S Bn 1 or 2 Sen 1 or 2 Htr Ckt Short Volts Test Status HO2S Bn 1 or 2 Sen 1 or 2 Htr Ckt Open Test Status HO2S Bn 1 or 2 Sen 1 or 2 Htr Ckt Short Gnd Test Status
  2. Observe the scan tool HO2S Bank 1 or 2 Sensor 1 or 2 Heater parameter . The amperage should be within the specified range listed below: 0.4-3.0 A for HO2S Bank 1 or 2 Sensor 1 0.4-2.8 A for HO2S Bank 1 or 2 Sensor 2
  3. Move the related wiring and connectors while observing the HO2S Heater parameter with a scan tool. The parameter should not change with movement. If movement affects the parameter, repair the appropriate harness or connector.
  4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate B52 HO2S.
  2. Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal D and ground. If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B52 HO2S heater circuit fuse is open, test all components connected to the fuse and replace as necessary.
  3. Connect a test lamp between the appropriate control circuit terminal listed below and B+. Verify that the test lamp does not illuminate. B52 HO2S 1 terminal E B52 HO2S 2 terminal E If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.
  4. Engine idling, the test lamp should illuminate, or flash. If the test lamp does not illuminate, or flash, test the control circuit for a short to voltage, or an open/high resistance. If the circuit/connections test normal, replace the K20 ECM.
  5. Ignition OFF, connect a 10 A fused jumper wire between the control circuit terminal listed below and the ignition voltage circuit terminal D. B52 HO2S 1 terminal E B52 HO2S 2 terminal E
  6. Engine idling, observe the appropriate HO2S Bank 1 or 2 Sensor 1 or 2 Heater parameter. The scan tool should display 0.00 A. If greater than the specified value, test the control circuit and the ignition voltage circuit for high resistance.
  7. If all circuits test normal, test or replace the appropriate B52 HO2S.

Perform the Diagnostic Repair Verification after completing the repair

  1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  3. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  4. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 2»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  5. Perform the scan tool Heated Oxygen Sensor Resistance Learn Reset after replacing a HO2S.
  6. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) uses the following information to calculate an expected airflow rate

  1. The throttle position (TP)
  2. The barometric pressure (BARO)
  3. The manifold absolute pressure (MAP)
  4. The intake air temperature (IAT)
  5. The engine RPM

The intake flow rationality diagnostic provides the within-range rationality check for the mass air flow (MAF), manifold absolute pressure (MAP), and the throttle position (TP) sensors. This is an explicit model-based diagnostic containing 4 separate models for the intake system.

  1. The throttle model describes the flow through the throttle body and is used to estimate the MAF through the throttle body as a function of barometric pressure (BARO), TP, intake air temperature (IAT), and estimated MAP. The information from this model is displayed on the scan tool as the MAF Performance Test parameter.
  2. The first intake manifold model describes the intake manifold and is used to estimate MAP as a function of the MAF into the manifold from the throttle body and the MAF out of the manifold caused by engine pumping. The flow into the manifold from the throttle uses the MAF estimate calculated from the above throttle model. The information from this model is displayed on the scan tool as the MAP Performance Test 1 parameter.
  3. The second intake manifold model is identical to the first intake manifold model except that the MAF sensor measurement is used instead of the throttle model estimate for the throttle air input. The information from this model is displayed on the scan tool as the MAP Performance Test 2 parameter.
  4. The fourth model is created from the combination and additional calculations of the throttle model and the first intake manifold model. The information from this model is displayed on the scan tool as the TP Performance Test parameter.

The estimates of MAF and MAP obtained from this system of models and calculations are then compared to the actual measured values from the MAF, MAP, and the TP sensors and to each other to determine the appropriate DTC to fail.

Conditions for Running the DTCs

P0068

  1. DTCs P0641, P0651, P1516, P2101, P2119, P2176 are not set.
  2. The engine is running.
  3. This DTC runs continuously when the above conditions are met.

P1101

  1. DTCs P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0335, P0336 are not set.
  2. The engine speed is between 450-6,800 RPM.
  3. The IAT Sensor parameter is between -7 to +125°C (+19 to +257°F).
  4. The ECT Sensor parameter is between -7 to +125°C (+19 to +257°F).
  5. This DTC runs continuously within the enabling conditions.

Conditions for Setting the DTCs

P0068

The ECM detects that the throttle position and the indicated engine load do not correspond with the expected load and throttle position for less than 1 s.

P1101

The engine control module (ECM) detects that the actual measured airflow from the MAF, MAP, and TP sensors is not within range of the calculated airflow that is derived from the system of models for more than 0.5 s.

Action Taken When the DTCs Set

P0068

  1. DTC P0068 is a Type A DTC.
  2. The control module commands the throttle actuator control (TAC) system to operate in the Reduced Engine Power mode.
  3. A message center or an indicator displays Reduced Engine Power.
  4. Under certain conditions the control module commands the engine OFF.

P1101

DTC P1101 is a Type B DTC.

Conditions for Clearing the MIL/DTCs

  1. DTC P0068 is a Type A DTC.
  2. DTC P1101 is a Type B DTC.

Diagnostic Aids

  1. A steady or intermittent high resistance of 15 ohms or greater on the ignition 1 voltage circuit will cause the MAF sensor signal to be increased by as much as 60 g/s. To pinpoint this condition perform a voltage drop test on the circuit.
  2. Any type of contamination on the MAF sensor heating elements will degrade the proper operation of the sensor. Certain types of contaminants act as a heat insulator, which will impair the response of the sensor to airflow changes. Water or snow can create the opposite effect, and cause the signal to increase rapidly.
  3. Depending on the current ambient temperature, and the vehicle operating conditions, a MAF sensor signal circuit that is shorted to the IAT signal circuit will increase or decrease the MAF sensor signal that is interpreted by the ECM. Additionally it may cause a rapid fluctuation in the IAT Sensor parameter.
  4. A skewed or stuck engine coolant temperature (ECT) or IAT sensor will cause the calculated models to be inaccurate and may cause this DTC to run when it should not. Refer to «Temperature Versus Resistance»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-specifications__temperature-versus-resistance) .
  5. Certain aftermarket air filters may cause this DTC to set.
  6. Certain aftermarket air induction systems may cause this DTC to set.
  7. Modifications to the air induction system may cause this DTC to set.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify the scan tool TB Idle Airflow Compensation parameter is less than 90 %. 90 % or greater Refer to «Throttle Body Cleaning»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__throttle-body-cleaning) . If less than 90 %
  3. Verify the scan tool TP Sensors 1 and 2 Agree/Disagree parameter displays Agree while performing the Throttle Sweep Test with a scan tool. If Disagree Refer to «DTC P0120-P0123, P0220, P0222, P0223, or P2135»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) for further diagnosis. If Agree
  4. Determine the current vehicle testing altitude.
  5. Verify the scan tool MAP Sensor pressure parameter is within the range specified in the «Altitude Versus Barometric Pressure»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-specifications__altitude-versus-barometric-pressure) table. The MAP Sensor pressure is not in range Refer to «DTC P0106»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) for further diagnosis. The MAP Sensor pressure is within range
  6. Engine idling, verify the scan tool MAP Sensor pressure parameter is between 26-52 kPa (3.8-7.5 psi) and changes with accelerator pedal input. If not between 26-52 kPa (3.8-7.5 psi) or does not change Refer to «DTC P0106»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) for further diagnosis. If between 26-52 kPa (3.8-7.5 psi) and changes
  7. Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below. Engine idling Perform the scan tool snapshot function. Increase the engine speed slowly to 3,000 RPM and then back to idle. Exit from the scan tool snapshot and review the data. Observe the MAF Sensor parameter frame by frame with a scan tool. The MAF Sensor parameter does not change smoothly and gradually Refer to «DTC P0068 or P1101»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) for further diagnosis. The MAF Sensor parameter changes smoothly and gradually
  8. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  9. Verify a DTC does not set. If any DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If no DTCs set
  10. All OK
  1. Perform the «Diagnostic Repair Verification»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-repair-verification) after completing the repair.
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
Ignition 1 VoltageP0102P0101P0102P0101, P0103
MAF Sensor SignalP0102P0102P0102P0102P0101, P0103, P1101
GroundP0102P0102P0102
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine Running at various operating conditions Parameter Normal Range: 1,700-9,500 Hz
Ignition 1 Voltage0 Hz0 Hz
MAF Sensor Signal0 Hz0 Hz0 Hz
Ground0 Hz

MAF Sensor

The engine control module (ECM) uses the following information to calculate an expected airflow rate

  1. The throttle position (TP)
  2. The barometric pressure (BARO)
  3. The manifold absolute pressure (MAP)
  4. The intake air temperature (IAT)
  5. The engine RPM

The intake flow rationality diagnostic provides the within-range rationality check for the mass air flow (MAF), manifold absolute pressure (MAP), and the throttle position (TP) sensors. This is an explicit model-based diagnostic containing 4 separate models for the intake system.

  1. The throttle model describes the flow through the throttle body and is used to estimate the MAF through the throttle body as a function of barometric pressure (BARO), TP, intake air temperature (IAT), and estimated MAP. The information from this model is displayed on the scan tool as the MAF Performance Test parameter.
  2. The first intake manifold model describes the intake manifold and is used to estimate MAP as a function of the MAF into the manifold from the throttle body and the MAF out of the manifold caused by engine pumping. The flow into the manifold from the throttle uses the MAF estimate calculated from the above throttle model. The information from this model is displayed on the scan tool as the MAP Performance Test 1 parameter.
  3. The second intake manifold model is identical to the first intake manifold model except that the MAF sensor measurement is used instead of the throttle model estimate for the throttle air input. The information from this model is displayed on the scan tool as the MAP Performance Test 2 parameter.
  4. The fourth model is created from the combination and additional calculations of the throttle model and the first intake manifold model. The information from this model is displayed on the scan tool as the TP Performance Test parameter.

The estimates of MAF and MAP obtained from this system of models and calculations are then compared to the actual measured values from the MAF, MAP, and the TP sensors and to each other to determine the appropriate DTC to fail.

  1. DTCs P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0335, P0336 are not set.
  2. The engine speed is between 450-6,800 RPM.
  3. The IAT Sensor parameter is between -7 to +125°C (+19 to +257°F).
  4. The ECT Sensor parameter is between -7 to +125°C (+19 to +257°F).
  5. This DTC runs continuously within the enabling conditions.

The engine control module (ECM) detects that the actual measured airflow from the MAF, MAP, and TP sensors is not within range of the calculated airflow that is derived from the system of models for more than 0.5 second.

DTC P0101 is a Type B DTC.

DTC P0101 is a Type B DTC.

  1. A steady or intermittent high resistance of 15 ohms or greater on the ignition 1 voltage circuit will cause the MAF sensor signal to be increased by as much as 60 g/s. To pinpoint this condition perform a voltage drop test on the circuit.
  2. Any type of contamination on the MAF sensor heating elements will degrade the proper operation of the sensor. Certain types of contaminants act as a heat insulator, which will impair the response of the sensor to airflow changes. Water or snow can create the opposite effect, and cause the signal to increase rapidly.
  3. Depending on the current ambient temperature, and the vehicle operating conditions, a MAF sensor signal circuit that is shorted to the IAT signal circuit will increase or decrease the MAF sensor signal that is interpreted by the ECM. Additionally it may cause a rapid fluctuation in the IAT Sensor parameter.
  4. A skewed or stuck engine coolant temperature (ECT) or IAT sensor will cause the calculated models to be inaccurate and may cause this DTC to run when it should not. Refer to «Temperature Versus Resistance»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-specifications__temperature-versus-resistance) .
  5. Certain aftermarket air filters may cause this DTC to set.
  6. Certain aftermarket air induction systems may cause this DTC to set.
  7. Modifications to the air induction system may cause this DTC to set.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 38522 Variable Signal Generator

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

  1. If you were sent here from DTC P0068, P0106, P0121, or P1101 refer to Circuit/System Testing.
  2. Ignition ON.
  3. Verify the scan tool TB Idle Airflow Compensation parameter is less than 90 %. 90 % or greater Refer to «Throttle Body Cleaning»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__throttle-body-cleaning) . If less than 90 %
  4. Verify the scan tool TP Sensors 1 and 2 Agree/Disagree parameter displays Agree while performing the Throttle Sweep Test with a scan tool. If Disagree Refer to «DTC P0120-P0123, P0220, P0222, P0223, or P2135»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) for further diagnosis. If Agree
  5. Determine the current vehicle testing altitude.
  6. Verify the scan tool MAP Sensor pressure parameter is within the range specified in the «Altitude Versus Barometric Pressure»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-specifications__altitude-versus-barometric-pressure) table. The MAP Sensor pressure is not in range Refer to «DTC P0106»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) for further diagnosis. The MAP Sensor pressure is within range
  7. Engine idling, verify the scan tool MAP Sensor pressure parameter is between 26-52 kPa (3.8-7.5 psi) and changes with accelerator pedal input. If not between 26-52 kPa (3.8-7.5 psi) or does not change Refer to «DTC P0106»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) for further diagnosis. If between 26-52 kPa (3.8-7.5 psi) and changes
  8. Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below. Engine idling Perform the scan tool snapshot function. Increase the engine speed slowly to 3,000 RPM and then back to idle. Exit from the scan tool snapshot and review the data. Observe the MAF Sensor parameter frame by frame with a scan tool. The MAF Sensor parameter does not change smoothly and gradually Refer to Circuit/System Testing. The MAF Sensor parameter changes smoothly and gradually
  9. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  10. Verify a DTC does not set. If the DTC sets Refer to Circuit/System Testing. If no DTCs set
  11. All OK

Note. You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

  1. Verify the integrity of the entire air induction system by inspecting for the following conditions: Improperly installed components Collapsed, restricted, or damaged components Loose clamps, cracks, or other damage An air flow restriction Restricted air filter Splits, kinks, leaks, or improper connections at the vacuum hoses Vacuum leaks at the intake manifold, MAP sensor, and throttle body Water intrusion In cold climates, inspect for any snow or ice buildup Inspect the B75B mass air flow sensor element for contamination If a condition is found If a condition is found, repair or replace component as appropriate. No condition found
  2. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B75B mass air flow /intake air temperature sensor. It may take up to 2 minutes for all vehicle systems to power down.
  3. Test for less than 2 ohms between the ground circuit terminal C and ground. If 2 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 2 ohms
  4. Ignition ON, verify a test lamp illuminates between the ignition 1 voltage circuit terminal B and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF. Test for less than 2 ohms in the ignition 1 voltage circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF. Test for infinite resistance between the ignition 1 voltage circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for greater than 2 ohms between the ignition 1 voltage circuit terminal B and ground. If less than 2 ohms, repair the short to ground on the circuit. If greater than 2 ohms, refer to «DTC P0685, P0689, P0690, or P1682»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) to verify the operation of the PWR/TRN Relay. If the test lamp illuminates
  5. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal A and ground. If less than 4.8 V Ignition OFF, disconnect the harness connector at the K20 ECM. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 ECM. If greater than 5.2 V Ignition OFF, disconnect the harness connector at the K20 ECM, ignition ON. Test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 ECM. If between 4.8-5.2 V
  6. Ignition OFF, connect the red lead of the J 38522 variable signal generator to the signal circuit terminal A at the harness connector. Connect the battery voltage supply to B+, and the black lead to ground.
  7. Set the J 38522 variable signal generator to the following specifications. Signal switch to 5 V Frequency switch to 5 KHz Duty Cycle switch to Normal
  8. Engine idling, observe the scan tool MAF Sensor parameter. The scan tool MAF Sensor parameter should be between 4,950-5,050 Hz. If not between 4,950-5,050 Hz. If not between 4,950-5,050 Hz., replace the K20 ECM. If between between 4,950-5,050 Hz.
  9. Test or replace the B75B mass air flow /intake air temperature sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
Ignition 1 VoltageP0102P0101, P0102P0102P0101, P0103
MAF Sensor SignalP0102P0102P0102P0102P0101, P0103, P1101
GroundP0102P0102P0102
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine running at various operating conditions Parameter Normal Range: 1,700-9,500 Hz
Ignition Voltage0 Hz0 Hz
MAF Sensor Signal0 Hz0 Hz0 Hz
Ground0 Hz

MAF Sensor

The mass air flow (MAF) sensor is integrated with the intake air temperature (IAT) sensor. The MAF sensor is an air flow meter that measures the amount of air entering the engine. The engine control module (ECM) uses the MAF sensor signal to provide the correct fuel delivery for all engine speeds and loads. A small quantity of air entering the engine indicates a deceleration or idle condition. A large quantity of air entering the engine indicates an acceleration or high load condition.

The ECM applies 5 V to the MAF sensor on the MAF sensor signal circuit. The sensor uses the voltage to produce a frequency based on the inlet air flow through the sensor bore. The frequency varies within a range of near 1,700 Hertz at idle to near 9,500 Hertz at maximum engine load.

  1. The engine is running for more than 1 s.
  2. The ignition signal is more than 8 V.
  3. The above conditions are met for more than 1 s.
  4. These DTCs run continuously when the above conditions are met.

P0102

The ECM detects that the MAF Sensor parameter is less than 1,400 Hz for greater than 5 s.

P0103

The ECM detects that the MAF Sensor parameter is more than 14,500 Hz for greater than 5 s.

DTCs P0102 and P0103 are Type B DTCs.

DTCs P0102 and P0103 are Type B DTCs.

  1. Verify the integrity of the air induction system by inspecting for the following conditions: Any water intrusion in the induction system Any contamination or debris on the sensing elements of the MAF sensor Damaged components
  2. Verify that any electrical aftermarket devices are properly connected and grounded. Refer to «Checking Aftermarket Accessories»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__checking-aftermarket-accessories) .

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 38522 Variable Signal Generator

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

  1. Ignition ON.
  2. Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below. Engine idling Perform the scan tool snapshot function. Increase the engine speed slowly to 3,000 RPM and then back to idle. Exit from the scan tool snapshot and review the data. Observe the MAF Sensor parameter frame by frame with a scan tool. The MAF Sensor parameter does not change smoothly and gradually Refer to Circuit/System Testing. The MAF Sensor parameter changes smoothly and gradually
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  4. Verify a DTC does not set. If the DTC sets Refer to Circuit/System Testing. If no DTCs set
  5. All OK

Note. You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B75B mass air flow /intake air temperature sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 2 ohms between the ground circuit terminal C and ground. If 2 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 2 ohms
  3. Ignition ON, verify a test lamp illuminates between the ignition 1 voltage circuit terminal B and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF. Test for less than 2 ohms in the ignition 1 voltage circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF. Test for infinite resistance between the ignition 1 voltage circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for greater than 2 ohms between the ignition 1 voltage circuit terminal B and ground. If less than 2 ohms, repair the short to ground on the circuit. If greater than 2 ohms, refer to «DTC P0685, P0689, P0690, or P1682»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) to verify the operation of the PWR/TRN Relay. If the test lamp illuminates
  4. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal A and ground. If less than 4.8 V Ignition OFF, disconnect the harness connector at the K20 ECM. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 ECM. If greater than 5.2 V Ignition OFF, disconnect the harness connector at the K20 ECM, ignition ON. Test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 ECM. If between 4.8-5.2 V
  5. Ignition OFF, connect the red lead of the J 38522 variable signal generator to the signal circuit terminal A at the harness connector. Connect the battery voltage supply to B+, and the black lead to ground.
  6. Set the J 38522 variable signal generator to the following specifications. Signal switch to 5 V Frequency switch to 5 KHz Duty Cycle switch to Normal
  7. Engine idling, observe the scan tool MAF Sensor parameter. The scan tool MAF Sensor parameter should be between 4,950-5,050 Hz. If not between 4,950-5,050 Hz. If not between 4,950-5,050 Hz., replace the K20 ECM. If between between 4,950-5,050 Hz.
  8. Test or replace the B75B mass air flow /intake air temperature sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
5-Volt ReferenceP0107, P0452, P0522, P0532, P0641P0106, P0107P0107P0106, P0108, P0453, P0533, P0641P0106, P0107
MAP Sensor SignalP0107P0106, P0107P0107P0106, P0108P0106, P0107, P1101
Low ReferenceP0106, P0108P0106, P0108P0106, P0108
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine running, transmission in Park or Neutral Parameter Normal Range: 20-48 kPa (Varies with altitude)
5-Volt Reference10 kPa10 kPa104 kPa
MAP Sensor Signal10 kPa10 kPa104 kPa
Low Reference80-103 kPa

MAP Sensor

Circuit Description

The intake flow rationality diagnostic provides the within-range rationality check for the mass air flow (MAF), manifold absolute pressure (MAP), and the throttle position (TP) sensors. This is an explicit model-based diagnostic containing 4 separate models for the intake system.

  1. The throttle model describes the flow through the throttle body and is used to estimate the MAF through the throttle body as a function of barometric pressure (BARO), TP, intake air temperature (IAT), and estimated MAP. The information from this model is displayed on the scan tool as the MAF Performance Test parameter.
  2. The first intake manifold model describes the intake manifold and is used to estimate MAP as a function of the MAF into the manifold from the throttle body and the MAF out of the manifold caused by engine pumping. The flow into the manifold from the throttle uses the MAF estimate calculated from the above throttle model. The information from this model is displayed on the scan tool as the MAP Performance Test 1 parameter.
  3. The second intake manifold model is identical to the first intake manifold model except that the MAF sensor measurement is used instead of the throttle model estimate for the throttle air input. The information from this model is displayed on the scan tool as the MAP Performance Test 2 parameter.
  4. The fourth model is created from the combination and additional calculations of the throttle model and the first intake manifold model. The information from this model is displayed on the scan tool as the TP Performance Test parameter.

The estimates of MAF and MAP obtained from this system of models and calculations are then compared to the actual measured values from the MAF, MAP, and the TP sensors and to each other to determine the appropriate DTC to fail. The following table illustrates the possible failure combinations and the resulting DTC or DTCs.

MAF Performance TestMAP Performance Test 1MAP Performance Test 2TP Performance TestDTCs PassedDTCs Failed
OKOKP0101, P0106, P0121, P1101None
OKOKFaultOKP0101, P0106, P0121, P1101None
FaultOKFaultOKP0106, P0121, P1101P0101
OKFaultFaultOKP0101, P0121, P1101P0106
FaultFaultFaultOKP0121, P1101P0101, P0106
OKFaultP0101, P0106, P1101P0121
OKOKFaultFaultP0101, P0106, P0121, P1101None
FaultOKFaultFaultP0101, P0106, P0121P1101
FaultFaultFaultP0101, P0106, P0121P1101

Scan Tool Diagnostic Test Results

  1. DTCs P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0335, P0336 are not set.
  2. The engine is running.
  3. The IAT Sensor parameter is between -7 and +125°C (+19 and +257°F).
  4. The ECT Sensor parameter is between 70-125°C (158-257°F).
  5. This DTC runs continuously when the above conditions are met.

The engine control module (ECM) detects that the MAP sensor pressure is not within range of the calculated pressure that is derived from the system of models for more than 0.5 second.

DTC P0106 is a Type B DTC.

DTC P0106 is a Type B DTC.

IMPORTANTVerify that the engine is in good mechanical condition before continuing with this diagnostic.
  1. A skewed or stuck engine coolant temperature (ECT) or IAT sensor will cause the calculated models to be inaccurate and may cause this DTC to run when it should not. Refer to «Temperature Versus Resistance»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-specifications__temperature-versus-resistance) .
  2. The BARO that is used by the ECM to calculate the air flow models is initially based on the MAP sensor at ignition ON. When the engine is running, the ECM will continually update the BARO value near wide open throttle using the MAP sensor and a calculation. A skewed MAP sensor will cause the BARO value to be inaccurate. Use the scan tool and compare the BARO parameter at ignition ON to the Altitude vs. Barometric Pressure Table. Refer to «Altitude Versus Barometric Pressure»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-specifications__altitude-versus-barometric-pressure) .
  3. A skewed MAP sensor will also cause the first and second intake manifold models to disagree with the actual MAP sensor measurements. Use the scan tool and compare the MAP Sensor parameter to a known good vehicle, under various operating conditions.
  4. Inspect for the following conditions: Incorrect CAM timing-Refer to «Camshaft Timing Chain, Sprocket, and Tensioner Replacement»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3__camshaft-timing-chain-sprocket-and-tensioner) for the correct timing. Worn piston rings-Refer to «Engine Compression Test»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3__engine-compression-test) .

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

  1. J-23738-A Mityvac
  2. J-35555 Metal Mityvac
  1. The BARO that is used by the ECM to calculate the air flow models is initially based on the MAP sensor at ignition ON. When the engine is running, the ECM will continually update the BARO value near WOT using the MAP sensor and a calculation. A skewed MAP sensor will cause the BARO value to be inaccurate. Determine the current vehicle testing altitude. Ignition ON, observe the scan tool BARO Sensor parameter. Compare the parameter to the Altitude vs Barometric Pressure table. Refer to «Altitude Versus Barometric Pressure»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-specifications__altitude-versus-barometric-pressure) .
  2. A skewed MAP sensor will also cause the first and second intake manifold models to disagree with the actual MAP sensor measurements. Use the scan tool and compare the MAP Sensor parameter to a known good vehicle under various operating conditions.
IMPORTANTAll electrical components and accessories must be turned OFF and allowed to power down.
  1. Verify the integrity of the air induction system by inspecting for the following conditions: Any damaged components Loose or improper installation Improperly routed vacuum hoses Any vacuum leak Any type of restriction MAP sensor seal that is missing or damaged
  2. Verify that restrictions do not exist in the MAP sensor vacuum source.
  3. Verify that restrictions do not exist in the exhaust system. Refer to «Restricted Exhaust»(/chevrolet/express-g3500/2013-2013/remont/exhaust/#engine-exhaust-system) .
  4. Ignition OFF, disconnect the MAP harness connector at the MAP sensor.
  5. Ignition OFF for 90 seconds, test for less than 5 ohms between the low reference circuit and ground. If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  6. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit and ground. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  7. Verify the scan tool MAP Sensor parameter is less than 12 kPa. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  8. Install a 3A fused jumper wire between the signal circuit and the 5-volt reference circuit. Verify the scan tool MAP Sensor parameter is greater than 103 kPa. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
  9. If all circuits test normal, test or replace the MAP sensor.

Component Testing

IMPORTANTYou must perform the Circuit/System Testing in order to verify the integrity of the MAP sensor circuits before proceeding with the Component Testing.

Skewed Sensor Test

  1. Ignition OFF, remove the vacuum source from the MAP sensor.
  2. Ignition ON, observe and record the scan tool MAP sensor pressure parameter. This is the first MAP sensor reading.
  3. With the J-23738-A mityvac or J-35555 metal mityvac , apply 17 kPa (5 inches Hg ) of vacuum to the MAP sensor. Observe and record the scan tool MAP sensor pressure parameter. This is the second MAP sensor reading.
  4. Subtract the second MAP sensor reading from the first MAP sensor reading. Verify that the vacuum decrease is within 14 kPa (1 inch Hg) of the applied vacuum. If the vacuum decrease is not within the specified range, replace the MAP sensor.
  5. With the J-23738-A mityvac or J-35555 metal mityvac , apply 34 kPa (10 inches Hg) of vacuum tot he MAP sensor. Observe and record the scan tool MAP sensor pressure parameter. This is the third MAP sensor reading.
  6. Subtract the third MAP sensor reading from the first MAP sensor reading. Verify that the vacuum decrease is within 4 kPa (1 inch Hg) of the applied vacuum. If the vacuum decrease is not within the specified range, replace the MAP sensor.

Erratic Signal Test

  1. Ignition OFF, remove the MAP sensor.
  2. Install a 3A fused jumper wire between the 5-volt reference circuit terminal 1 and the corresponding terminal of the MAP sensor.
  3. Install a jumper wire between the low reference circuit terminal 2 of the MAP sensor and ground.
  4. Install a jumper wire at terminal 3 of the MAP sensor.
  5. Connect a DMM between the jumper wire from terminal 3 of the MAP sensor and ground.
  6. Ignition ON, with the J-23738-A mityvac or J-35555 metal mityvac , slowly apply vacuum to the sensor while observing the voltage on the DMM. The voltage should vary between 0-5.2 volts, without any spikes or dropouts. If the voltage reading is erratic, replace the MAP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Manifold Absolute Pressure Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
5-Volt ReferenceP0107, P0452, P0522, P0532, P0641P0106, P0107P0107P0106, P0108, P0453, P0522, P0533, P0641P0106, P0107
MAP Sensor SignalP0107P0106, P0107P0107P0108P0106, P0107, P1101
Low ReferenceP0106, P0108P0106, P0108P0106, P0108
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine running, transmission in Park or Neutral Parameter Normal Range: 20-48 kPa (Varies with altitude)
5-Volt Reference0 kPa0 kPa127 kPa
MAP Sensor Signal0 kPa0 kPa127 kPa
Low Reference127 kPa

MAP Sensor

The manifold absolute pressure (MAP) sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by engine speed, throttle opening, air temperature, and barometric pressure (BARO). A diaphragm within the MAP sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The sensor translates this action into electrical resistance. The MAP sensor wiring includes 3 circuits. The engine control module (ECM) supplies a regulated 5 volts to the sensor on a 5-volt reference circuit. The ECM supplies a ground on a low reference circuit. The MAP sensor provides a signal voltage to the ECM, relative to the pressure changes, on the MAP sensor signal circuit. The ECM converts the signal voltage input to a pressure value.

Under normal operation the highest pressure that can exist in the intake manifold is equal to BARO. This occurs when the vehicle is operated at wide-open throttle (WOT) or when the ignition is on while the engine is off. Under these conditions, the ECM uses the MAP sensor to determine the current BARO. The lowest manifold pressures occur when the vehicle is idling or decelerating. MAP can range from 10 kPa, when pressures are low, to as much as 104 kPa when pressures are high, depending on the BARO. The ECM monitors the MAP sensor signal for pressure outside of the normal range.

P0107

  1. DTCs P0641, P0651, P1516, P2101, P2125, P2135, P2138, P2176 are not set.
  2. The engine speed is greater than 400 RPM.
  3. The throttle angle is greater than 0 percent when the engine speed is less than 800 RPM. OR The throttle angle is greater than 13 percent when the engine speed is greater than 800 RPM.
  4. This DTC runs continuously when the above conditions are met.

P0108

  1. DTCs P1516, P2101, P2125, P2135, P2138, P2176 are not set.
  2. The engine has been running for a period of time that is determined by the start-up engine coolant temperature (ECT). The time ranges from 8 seconds at less than -30°C (-22°F) to 3 seconds at greater than 30°C (86°F).
  3. The throttle angle is less than one percent when the engine speed is less than 1,200 RPM. OR
  4. The throttle angle is less than 20 percent when the engine speed is greater than 1,200 RPM.
  5. This DTC runs continuously when the above conditions are met.

P0107

The ECM detects that the MAP sensor voltage is less than 0.10 volt for greater than 4 seconds.

P0108

The ECM detects that the MAP sensor voltage is more than 4.90 volts for greater than 4 seconds.

DTCs P0107 and P0108 are Type B DTCs.

DTCs P0107 and P0108 are Type B DTCs.

Verify the integrity of the MAP sensor system by inspecting for the following conditions

  1. Intake manifold vacuum leaks
  2. Any damage to the MAP sensor housing
  3. Any damage to the MAP sensor seal
  4. A loose or improperly installed MAP sensor
  5. A restriction in the vacuum source of the MAP sensor

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

  1. J-23738-A Mityvac
  2. J-35555 Metal Mityvac
  1. Verify that the following DTCs are not set: P0641 or P0651. If any of the DTCs are set, refer to «DTC P0641 or P0651»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  2. Ignition ON, observe the MAP Sensor parameter. The reading should be between 0.05-4.9 volts.
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition OFF, disconnect the harness connector at the MAP sensor.
  2. Ignition OFF for 90 seconds, test for less than 5 ohms between the low reference circuit terminal 2 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 1 and ground. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  4. Verify the scan tool MAP Sensor parameter is less than 2 kPa. If greater than the specified range, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the ECM.
  5. Install a 3A fused jumper wire between the signal circuit terminal 3 and the 5-volt reference circuit terminal 1. Verify the scan tool MAP Sensor parameter is greater than 126 kPa. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
  6. If all circuits test normal, test or replace the MAP sensor.
IMPORTANTYou must perform the Circuit/System Testing in order to verify the integrity of the MAP sensor circuits before proceeding with the Component Testing.
  1. Ignition OFF, remove the MAP sensor.
  2. Install a 3A fused jumper wire between the 5-volt reference circuit terminal 1 and the corresponding terminal of the MAP sensor.
  3. Install a jumper wire between the low reference circuit terminal 2 of the MAP sensor and ground.
  4. Install a jumper wire at terminal 3 of the MAP sensor.
  5. Connect a DMM between the jumper wire from terminal 3 of the MAP sensor and ground.
  6. Ignition ON, with the J-23738-A mityvac or J-35555 metal mityvac , slowly apply vacuum to the sensor while observing the voltage on the DMM. The voltage should vary between 0-5.2 volts without any spikes or dropouts. If the voltage reading is erratic, replace the MAP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Manifold Absolute Pressure Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
IAT Sensor SignalP0112P0113P0113*
Low ReferenceP0113P0113*
*ECM or sensor damage may occur if the circuit is shorted to B+.
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine running Parameter Normal Range: Varies with ambient temperature
IAT Sensor Signal150°C (302°F)40°C (-40°F)40°C (-40°F)*
Low Reference40°C (-40°F)40°C (-40°F)
* Internal ECM or sensor damage may occur if the circuit is shorted to B+.

IAT Sensor

The intake air temperature (IAT) sensor is a variable resistor. The IAT sensor has a signal circuit and a low reference circuit. The IAT sensor measures the temperature of the air entering the engine. The engine control module (ECM) supplies 5 V to the IAT signal circuit and a ground for the IAT low reference circuit.

P0112

  1. DTCs P0116, P0117, P0118, P0128, P0502, P0503 are not set.
  2. The engine is running for greater than 10 s.
  3. The engine coolant temperature (ECT) is colder than 150°C (302°F).
  4. This DTC runs continuously when the above conditions are met.

P0113

  1. DTCs P0101, P0102, P0103, P0116, P0117, P0118, P0128, P0502, P0503 are not set.
  2. The engine is running for greater than 10 s.
  3. The ECT is warmer than -40°C (-40°F).
  4. The MAF Sensor parameter is greater than 512 g/s.
  5. This DTC runs continuously when the above conditions are met.

P0112

The ECM detects that the IAT sensor parameter is warmer than 149°C (300°F) for greater than 5 s.

P0113

The ECM detects that the IAT sensor parameter is colder than -39°C (-38°F) for greater than 5 s.

DTCs P0112 and P0113 are Type B DTCs.

DTCs P0112 and P0113 are Type B DTCs.

  1. With the ignition ON, and the engine OFF, if the engine is cold, a properly functioning IAT sensor will gradually increase the scan tool IAT Sensor parameter. This is due to the heat that is generated by the mass air flow (MAF) sensor heating elements.
  2. Depending on the ambient temperature, an IAT sensor signal circuit or low reference circuit that is shorted to the MAF sensor signal circuit can cause a DTC P0113 to set. This condition causes a rapid fluctuation in the IAT Sensor parameter.
  3. An IAT sensor signal circuit that is shorted to the MAF sensor ignition circuit can cause a DTC P0113 to set.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Engine idling, observe the scan tool IAT Sensor parameter. The reading should be between -38 to +149°C (-36 to +300F) depending on the current ambient temperature and the vehicle operating conditions.
  2. Operate the vehicle within the Conditions for Running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition OFF, disconnect the harness connector at the MAF/IAT sensor.
  2. Ignition OFF, all vehicles systems OFF, this may take up to for 2 min, test for less than 5 ohms between the IAT low reference circuit terminal A and ground. If greater than the specified range, test the IAT low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  3. Ignition ON, verify the scan tool IAT parameter is colder than -39°C (-38°F). If warmer than the specified range, test the IAT signal circuit terminal B for a short to ground. If the circuit tests normal, replace the ECM.
  4. Install a 3 A fused jumper wire between the IAT signal circuit terminal B and ground. Verify the scan tool IAT parameter is warmer than 149°C (300°F). If colder than the specified range, test the IAT signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
  5. If all circuits test normal, test or replace the MAF/IAT sensor.

Measure and record the resistance of the IAT sensor at various ambient temperatures, and then compare those measurements to the Temperature vs Resistance Table. Refer to Temperature Versus Resistance .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
ECT Sensor SignalP0117P0118P0118P0118P0116, P0128
Low ReferenceP0118P0118P0118P0128
CircuitNormal RangeShort to GroundOpenShort to Voltage
ECT Sensor Signal39 to +120°C (-38 to +248°F)150°C (302°F)40°C (-40°F)40°C (-40°F)
Low Reference40°C (-40°F)40°C (-40°F)

ECT Sensor Temperature

The engine coolant temperature (ECT) sensor is a variable resistor that measures the temperature of the engine coolant. The engine control module (ECM) supplies 5 volts to the ECT signal circuit and supplies a ground to the low reference circuit.

The ECM uses this high side coolant rationality diagnostic to determine if the input from the ECT sensor is skewed warmer than normal. The internal clock of the ECM will record the amount of time the ignition is OFF. If the calibrated ignition OFF time is met at start-up, the ECM will compare the temperature difference between the ECT and the intake air temperature (IAT), to determine if the temperatures are within an acceptable operating range of each other.

  1. DTCs P0112, P0113, P0117, P0118, P0502, P0503, P0601, P0603, P062F, P2610 are not set.
  2. The vehicle has had a minimum ignition OFF time of 10 hours.
  3. The ignition is ON.
  4. The start-up IAT is more than -7°C (+19°F).
  5. The Fuel Level Sensor parameter is more than 5 percent.
  6. This DTC runs once per ignition cycle when the above conditions are met.
  1. The ECM detects a temperature difference at power-up that indicates that the ECT sensor is 30°C (54°F) more than the IAT sensor. OR
  2. The ECM detects a temperature difference at power-up that indicates that the ECT sensor is 10°C (18°F) more than the IAT sensor, and the time spent cranking the engine is more than 10 seconds, when the fuel level is more than 5 percent. OR
  3. With the power-up IAT more than -7°C (+19°F), the ECM detects a temperature difference at power-up that indicates that the ECT sensor is 20°C (36°F) more than the IAT sensor. Then the vehicle must be driven for more than 6 minutes and 40 seconds at more than 40 km/h (25 mph). If the IAT sensor then decreases more than 4°C (7°F), an engine block heater was detected and the test is aborted. If the IAT sensor does not decrease, an engine block heater was not detected and DTC P0116 will set.

DTC P0116 is a Type B DTC.

DTC P0116 is a Type B DTC.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. If the ignition has been OFF for 8 hours or more, the ECT and the IAT, should be within 6°C (11°F) of each other and also the ambient temperature. Turn ON the ignition, with the engine OFF, and use a scan tool to observe the IAT and the ECT sensor parameters. Compare those sensor parameters to each other and also to the ambient temperature. A slight to moderate resistance in the IAT signal or low reference circuit, can widen the spread between the two sensors and cause this DTC to set.
  2. An IAT sensor that is skewed lower at various ambient temperatures, due to more resistance than is normal, can widen the spread between the two sensors and cause this DTC to set. Measure and record the resistance of the IAT sensor at various ambient temperatures, and then compare those measurements to the Temperature vs Resistance Table. Refer to «Temperature Versus Resistance»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-specifications__temperature-versus-resistance) .
  3. Inspect the ECT sensor terminals for corrosion, and for engine coolant leaking through the sensor.
  4. Turn OFF the ignition.
  5. Inspect the cooling system surge tank for the proper engine coolant level. Refer to «Cooling System Leak Testing»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-leak-testing) , and «Cooling System Draining and Filling (Vac N Fill)»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-vac) , «Cooling System Draining and Filling (Static Fill Diesel)»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system) .

Note. All electrical components and accessories must be turned OFF and allowed to power down.

  1. Ignition OFF, disconnect the ECT harness connector at the ECT sensor.
  2. Ignition OFF, test for less than 5 ohms between the low reference circuit and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  3. Ignition ON, verify the scan tool ECT Sensor parameter is less than -39°C (-38°F). If greater than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM.
  4. Install a 3A fused jumper wire between the signal circuit and the low reference circuit. Verify the scan tool ECT Sensor parameter is greater than 149°C (300°F). If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
  5. If all circuits test normal, test or replace the ECT sensor.

Measure and record the resistance of the ECT sensor at various ambient temperatures, then compare those measurements to the Temperature vs Resistance Table. Refer to Temperature Versus Resistance .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Engine Coolant Temperature Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
ECT Sensor SignalP0117P0118P0118*P0118P0116, P0125, P0128
Low ReferenceP0118P0118*P0118P0125, P0128
*ECM or sensor damage may occur if the circuit is shorted to B+
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine operating in Closed Loop Parameter Normal Range: Varies with coolant temperature
ECT Sensor Signal150°C (302°F)40°C (-40°F)40°C (-40°F)
Low Reference40°C (-40°F)40°C (-40°F)

ECT Sensor Temperature

The engine coolant temperature (ECT) sensor is a variable resistor that measures the temperature of the engine coolant. The engine control module (ECM) supplies 5 volts to the ECT signal circuit and supplies a ground to the low reference circuit.

P0117

  1. The engine is running for greater than 10 seconds. OR
  2. The ignition is ON when the intake air temperature (IAT) is less than 50°C (122°F).
  3. This DTC runs continuously when the above conditions are met.

P0118

  1. The engine is running for greater than 10 seconds. OR
  2. The ignition is ON when the IAT is more than 0°C (32°F).
  3. This DTC runs continuously when the above conditions are met.

P0117

The ECM detects that the ECT is more than 149°C (300°F) for greater than 5 seconds.

P0118

The ECM detects that the ECT is less than -39°C (-38°F) for greater than 5 seconds.

DTCs P0117 and P0118 are Type B DTCs.

DTCs P0117 and P0118 are Type B DTCs.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the ECT Sensor parameter. The reading should be between -37 to +139°C (-35 to +282°F).
  2. Operate the vehicle with the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
IMPORTANTAll electrical components and accessories must be turned OFF and allowed to power down.
  1. Ignition OFF, disconnect the ECT harness connector at the ECT sensor.
  2. Ignition OFF for 90 seconds, test for less than 5 ohms between the low reference circuit terminal A and ground. If greater than the specified range, test the low reference circuit terminal A for an open/high resistance. If the circuit tests normal, replace the ECM.
  3. Ignition ON, verify the scan tool ECT Sensor parameter is less than -39°C (-38°F). If greater than the specified range, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the ECM.
  4. Install a 3A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal A. Verify the scan tool ECT Sensor parameter is greater than 149°C (300°F). If less than the specified range, test the signal circuit terminal B for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
  5. If all circuits test normal, test or replace the ECT sensor.

Measure and record the resistance of the ECT sensor at various ambient temperatures, then compare those measurements to the Temperature vs Resistance table. Refer to Temperature Versus Resistance .

  1. «Engine Coolant Temperature Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
5 V ReferenceP0107, P0651, P0335P2135P0122, P0222P0651P0068, P0121
TP Sensor 1 SignalP0122P2135P0122P0123P0068, P0121
TP Sensor 2 SignalP0222P2135P0223P0223P0068, P0121
Low ReferenceP2135P0123, P0223P0068, P0121
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine running at various operating conditions Normal Range: 4.74-0.33 V
5 V Reference0 V0 V5 V
TP Sensor 1 Signal0 V0 V5 V
Low Reference4-5 V

TP Sensor 1

CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine running at various operating conditions Parameter Normal Range: 0.26-4.5 V
5 V Reference0 V0 V5 V
TP Sensor 2 Signal0 V5 V5 V
Low Reference5 V

TP Sensor 2

The throttle body assembly contains 2 throttle position (TP) sensors. The TP sensors are mounted to the throttle body assembly and are not serviceable. The TP sensors provide a signal voltage that changes relative to throttle blade angle. The engine control module (ECM) supplies the TP sensors with a common 5 V reference circuit, a common low reference circuit, and two independent signal circuits.

The TP sensors have opposite functionality. TP sensor 1 signal voltage decreases and TP sensor 2 signal voltage increases as the accelerator pedal increases to wide open throttle (WOT).

P0120, P0122, P0123, P0220, P0222, and P0223

  1. DTC P0641 or P0651 is not set.
  2. The run/crank or powertrain relay voltage is greater than 6 V and reduced power is not active.
  3. The ignition is ON or the engine is operating.
  4. DTC P0120, P0122, P0123, P0220, P0222, P0223 run continuously when the above conditions are met.

P0121

  1. DTCs P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0116, P0117, P0118, P0128, P0315, P0335, P0336, or P3400 is not set.
  2. The engine speed is between 450-6,700 RPM.
  3. The engine coolant temperature (ECT) is between -7 to +125°C (19-257°F).
  4. The intake air temperature (IAT) is between -20 to +125°C (-4 to +257°F).
  5. DTC P0121 runs continuously when the above conditions are met.

P2135

  1. DTC P0120, P0122, P0123, P0220, P0222, P0223, or P0651 is not set.
  2. The run/crank or powertrain relay voltage is greater than 6 V and reduced power is not active.
  3. The ignition is ON or the engine is operating.
  4. DTC P2135 runs continuously when the above conditions are met.

P0121

The ECM detects the TP sensor is stuck within range for greater than 1 s.

P0120

The ECM detects the TP sensor 1 voltage is less than 0.325 V or greater than 4.75 V for greater than 1 s.

P0122

The ECM detects the TP sensor 1 voltage is less than 0.325 V for greater than 1 s.

P0123

The ECM detects the TP sensor 1 voltage is greater than 4.75 V for greater than 1 s.

P0220

The ECM detects the TP sensor 2 voltage is less than 0.25 V or greater than 4.59 V for greater than 1 s.

P0222

The ECM detects that the TP sensor 2 voltage is less than 0.25 V for greater than 1 s.

P0223

The ECM detects the TP sensor 2 voltage is greater than 4.59 V for greater than 1 s.

P2135

The ECM detects the difference between the TP sensor 1 and TP sensor 2 exceeds a predetermined value for greater than 1 s.

  1. DTC P0120, P0122, P0123, P0220, P0222, P0223, and P2135 are Type A DTCs.
  2. DTC P0121 is a Type B DTC.
  3. The ECM commands the TAC system to operate in the Reduced Engine Power mode.
  4. A message center or an indicator displays Reduced Engine Power.
  5. Under certain conditions the control module commands the engine OFF.

DTCs P0120, P0122, P0123, P0220, P0222, P0223, and P2135 are Type A DTCs.

DTC P0121 is a Type B DTC.

  1. If the Throttle Sweep Test is not available on the scan tool, observe the scan tool TP Sensor 1 and 2 Agree/Disagree parameter while performing the following tests: Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times. Rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release pedal. Repeat the procedure several times. The TP Sensor 1 and 2 Agree/Disagree parameter should display Agree. If Disagree is displayed, continue diagnosis in Circuit/System Testing.
  2. A high resistance condition on the throttle position and throttle actuator control circuits could cause a DTC to set.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. If you were sent here from DTC P0068, P0101, P0106, or P1101 refer to Circuit/System Testing.
  2. Ignition ON.
  3. Verify that DTC P0641 or P0651 is not set. If DTC is set Refer to «DTC P0641 or P0651 (ECM)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) for further diagnosis. If DTC is not set
  4. Verify the scan tool TB Idle Airflow Compensation parameter is less than 90 %. 90 % or greater Refer to «Throttle Body Cleaning»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-repair-instructions__throttle-body-cleaning) . If less than 90 %
  5. Verify the scan tool TP Sensor 1 and TP Sensor 2 voltage parameters are between 1.0-4.0 V and change with accelerator pedal input. If not between 1.0-4.0 V or does not change Refer to Circuit/System Testing If between 1.0-4.0 V and changes
  6. Verify the scan tool TP Sensors 1 and 2 Agree/Disagree parameter displays Agree while performing the Throttle Sweep Test with a scan tool. If Disagree Refer to Circuit/System Testing If Agree
  7. Clear the DTCs with the scan tool. Operate the vehicle within the Conditions for Running the DTC or within the conditions that you observed from the Freeze Frame/Failure Records.
  8. Ignition ON.
  9. Verify that DTC P0120 or P0220 are not the only TP sensor DTCs set. If DTC P0120 or P0220 are the only DTCs set Replace the engine control module If DTC P0120 or P0220 are not set
  10. Verify DTC P0120, P0121, P0122, P0123, P0220, P0222, P0223, and P2135 is not set. If DTC is set Refer to Circuit/System Testing If DTC is not set
  11. Determine the current vehicle testing altitude.
  12. Verify the scan tool MAP Sensor pressure parameter is within range specified in the «Altitude Versus Barometric Pressure»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-specifications__altitude-versus-barometric-pressure) table. The MAP Sensor pressure is not in range Refer to «DTC P0106»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p0010-to-dtc-p0507) . The MAP Sensor pressure is within range
  13. Engine idling.
  14. Verify the scan tool MAP Sensor pressure parameter is between 26-52 kPa (3.8-7.5 psi) and changes with accelerator pedal input. If not between 26-52 kPa (3.8-7.5 psi) or does not change Refer to «DTC P0106»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p0010-to-dtc-p0507) . If between 26-52 kPa (3.8-7.5 psi) and changes
  15. Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below. Engine idling Perform the scan tool snapshot function. Increase the engine speed slowly to 3,000 RPM and then back to idle. Exit from the scan tool snapshot and review the data. Observe the MAF Sensor parameter frame by frame with a scan tool. The MAF Sensor parameter does not change smoothly and gradually Refer to «DTC P0101»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p0010-to-dtc-p0507) . The MAF Sensor parameter changes smoothly and gradually
  16. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  17. Verify a DTC does not set. If DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If DTC does not set
  18. All OK
  1. Ignition OFF, and all vehicle systems OFF, disconnect the harness connector at Q38 throttle body assembly. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference circuit terminal C and ground. If 5 ohms or greater Ignition OFF, disconnect the harness connector at the K20 engine control module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 engine control module. If less than 5 ohms
  3. Ignition ON.
  4. Test for 4.8-5.2 V between the 5 V reference circuit terminal E and ground. If less than 4.8 V Ignition OFF, disconnect the harness connector at the K20 engine control module. Test for infinite resistance between the 5 V reference circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the 5 V reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 engine control module. If greater than 5.2 V Ignition OFF, disconnect the harness connector at the K20 engine control module, ignition ON. Test for less than 1 V between the 5 V reference circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 engine control module. If between 4.8-5.2 V
  5. Ignition ON.
  6. Test for less than 1 V between the TP sensor 1 signal circuit terminal D and ground. If 1.0 V or greater Ignition OFF, disconnect the harness connector at the K20 engine control module, ignition ON. Test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 engine control module. If 1.0 V or less
  7. Install a 3 A fused jumper wire between TP sensor 1 signal circuit terminal D and the 5 V reference circuit terminal E.
  8. Verify the scan tool TP sensor 1 voltage parameter is greater than 4.8 V. If 4.8 V or less Ignition OFF, disconnect the harness connector at the K20 engine control module. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 engine control module. If 4.8 or greater
  9. Test for 4.8-5.2 V between the TP sensor 2 signal circuit terminal F and ground. If less than 4.8 V Ignition OFF, disconnect the harness connector at the K20 engine control module. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 engine control module. If greater than 5.2 V Ignition OFF, disconnect the harness connector at the K20 engine control module, ignition ON. Test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 engine control module. If between 4.8-5.2 V
  10. Test or replace the Q38 throttle body assembly.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Throttle Body Assembly Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
ECT Sensor SignalP0117P0118P0118P0118P0116, P0128
Low ReferenceP0118P0118P0118P0128
*ECM or sensor damage may occur if the circuit is shorted to B+
CircuitNormal RangeShort to GroundOpenShort to Voltage
Operating Conditions: Engine operating in Closed Loop Parameter Normal Range: Varies with coolant temperature
ECT Sensor Signal39 to +120°C (-38 to +248°F)150°C (302°F)40°C (-40°F)40°C (-40°F)
Low Reference40°C (-40°F)40°C (-40°F)

ECT Sensor Temperature

The engine coolant temperature (ECT) sensor is a variable resistor that measures the temperature of the engine coolant. The engine control module (ECM) supplies 5 volts to the ECT sensor signal circuit and supplies a ground to the low reference circuit.

The purpose of this diagnostic is to analyze the performance of the thermostat by using the ECT sensor to determine if the engine coolant will increase at the correct rate, and also to meet the calibrated target temperatures under various operating conditions.

The ECM uses the start-up ECT and the start-up intake air temperature (IAT) to begin the diagnostic calculation. The air flow into the engine is accumulated, and vehicle speed, distance, and engine run time are also factored in, to determine if the ECT does increase normally, and reach the calibrated target temperatures.

  1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0171, P0172, P0174, P0175, P0502, P0503 are not set.
  2. The start-up IAT is warmer than -7°C (+19°F).
  3. The start-up ECT is less than 70°C (158°F), when the IAT is above 10°C (50°F).
  4. The start-up ECT is colder than 50°C (122°F), when the IAT is below 10°C (50°F).
  5. The engine run time is between 90 seconds and 22 minutes.
  6. The vehicle has traveled greater than 2.4 kilometers (1.5 miles) at greater than 8 km/h (5 mph).
  7. The accumulated airflow is between 20-75 g/s, with the minimum average airflow greater than 10 g/s.
  8. The fuel ethanol percentage is less than 85 percent.
  9. This DTC runs once per ignition cycle when the above conditions are met.
  1. The ECM detects that the minimum ECT of 75°C (167°F) has not been met, when the IAT is greater than 10°C (50°F). OR
  2. The ECM detects that the minimum ECT of 55°C (131°F) has not been met, when the IAT is less than 10°C (50°F).

DTC P0128 is a Type B DTC.

DTC P0128 is a Type B DTC.

  1. DTC P0128 occurring with insufficient vehicle interior heating is an indication of improper thermostat operation.
  2. Inspect the ECT sensor terminals and the ECT harness connector for corrosion. This condition results in a greater voltage on the ECT sensor signal circuit, which is interpreted by the ECM as a colder ECT.
  3. This diagnostic runs in a specific range. Measure and record the resistance of the ECT sensor at various ambient temperatures between -7 to +80°C (+19 to +176°F), then compare those measurements to the Temperature Versus Resistance table. Refer to «Temperature Versus Resistance»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-specifications__temperature-versus-resistance) .
  4. A slight to moderate resistance in the ECT sensor signal circuit or low reference circuit will affect this diagnostic. This condition results in a greater voltage on the ECT sensor signal circuit, which is interpreted by the ECM as a colder ECT.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. If the ignition has been OFF for 8 hours or more, the ECT and the IAT, should be within 6°C (11°F) of each other and also the ambient temperature. Turn ON the ignition, with the engine OFF, and use a scan tool to observe the IAT and the ECT sensor parameters.
  2. Use the scan tool to verify the proper operation of the engine cooling system fans.
  3. Turn OFF the ignition.
  4. Inspect the cooling system surge tank for the proper engine coolant level. Refer to «Cooling System Leak Testing»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-leak-testing) , and «Cooling System Draining and Filling (Vac N Fill)»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-vac) , «Cooling System Draining and Filling (Static Fill Diesel)»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
  5. Verify the proper heat range, and the operation of the thermostat. Refer to «Thermostat Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system__thermostat-diagnosis) .
  6. Operate the vehicle with the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Note. All electrical components and accessories must be turned OFF and allowed to power down.

  1. Ignition OFF, disconnect the ECT harness connector at the ECT sensor.
  2. Ignition OFF for 90 seconds, test for less than 5 ohms between the low reference circuit terminal A and ground. If greater than the specified range, test the low reference circuit terminal A for an open/high resistance. If the circuit tests normal, replace the ECM.
  3. Ignition ON, verify the scan tool ECT Sensor parameter is less than -39°C (-38°F). If warmer than the specified range, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the ECM.
  4. Install a 3A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal A. Verify the scan tool ECT Sensor parameter is greater than 149°C (300°F). If colder than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
  5. If all circuits test normal, test or replace the ECT sensor.

Measure and record the resistance of the ECT sensor at various ambient temperatures, then compare those measurements to the Temperature vs Resistance table. Refer to Temperature Versus Resistance .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Engine Coolant Temperature Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Engine Coolant Thermostat Replacement (Diesel)»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system)
  3. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
HO2S High SignalP0131, P0137, P0151, P0157, P1133, P1153P0131, P0132, P0133, P0134, P0137, P0140, P0151, P0152, P0153, P0154, P0157, P0160, P1133, P1153P013A, P013B, P013C, P013D, P013E, P013F, P0131, P0132, P0133, P0134, P0137, P0138, P0140, P0151, P0152, P0153, P0154, P0157, P0158, P0160, P1133, P1153P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160, P1133, P1153P013A, P013B, P013C, P013D, P013E, P013F, P0133, P0134, P0140, P0153, P0154, P0160, P1133, P1153
HO2S Low SignalP0131, P0137, P0151, P0157P0131, P0132, P0133, P0134, P0138, P0140, P0151, P0152, P0153, P0154, P0158, P0160, P1133, P1153P013A, P013B, P013C, P013D, P013E, P013F, P0131, P0132, P0133, P0134, P0138, P0140, P0151, P0152, P0153, P0154, P0158, P0160, P1133, P1153P0134, P0138, P0140, P0154, P0158, P0160, P1133, P1153
CircuitShort to GroundOpenShort to Voltage
Parameter Normal Range: 200-800 mV
HO2S High Signal0 mVApproximately 470 mVApproximately 1,100 mV
HO2S Low Signal455 mVApproximately 450 mVApproximately 445 mV

HO2S Sensor 1 or 2 Voltage

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,275 mV. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.

The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the control module to calculate the air-to-fuel ratio sooner.

P0131, P0137, P0151, or P0157

  1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
  2. The engine is operating in Closed Loop.
  3. The Ignition 1 voltage is between 10-32 V.
  4. The fuel level is greater than 10 %.
  5. The throttle position (TP) is between 3-70 %.
  6. The DTCs run continuously when the above conditions are met for 2 s.

P0132, P0138, P0152, or P0158

  1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
  2. The engine is operating in Closed Loop.
  3. The Ignition 1 voltage is between 10-32 V.
  4. The fuel level is greater than 10 %.
  5. The throttle position (TP) is between 0-70 %.
  6. The DTCs run continuously when the above conditions are met for 2 s.

P0131, P0137, P0151, or P0157

  1. The ECM detects that the HO2S voltage is less than 50 mV.
  2. The DTCs set within 100 s when the above condition is met.

P0132, P0138, P0152, or P0158

  1. The ECM detects that the HO2S voltage is greater than 1,050 mV.
  2. The DTCs set within 15 s when the above condition is met.

DTCs P0131, P0132, P0137, P0138, P0151, P0152, and P0158 are Type B DTCs.

DTCs P0131, P0132, P0137, P0138, P0151, P0152, and P0158 are Type B DTCs.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the DTC information with a scan tool. Verify no HO2S heater DTCs are set. If a HO2S heater DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. Engine running, observe the appropriate scan tool HO2S Bank 1 or 2 Sensor 1 or 2 voltage parameter. The reading should be within the range of 50-1,050 mV.
  3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate B52 HO2S. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference circuit terminal A and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  3. Ignition ON, verify the appropriate scan tool B52 HO2S parameter is approximately 450 mV. If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM. If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
  4. Install a 3 A fused jumper wire between the signal circuit terminal B and ground. Verify the appropriate scan tool B52 HO2S parameter is less than 60 mV. If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
  5. If all circuits test normal, replace the appropriate B52 HO2S.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  3. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  4. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 2»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  5. Perform the scan tool Heated Oxygen Sensor Resistance Learn Reset after replacing a HO2S.
  6. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
HO2S High SignalP0131, P0137, P0151, P0157P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P013A, P013B, P013C, P013D, P013E, P013F, P0133, P014A, P014B, P0153, P1133, P1153, P2270, P2271, P2272, P2273
HO2S Low SignalP0131, P0137, P0151, P0157P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P0134, P0138, P0140, P0154, P0158, P0160P013A, P013B, P013C, P013D, P013E, P013F, P0133, P014A, P014B, P0153, P1133, P1153, P2270, P2271, P2272, P2273

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,275 mV. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.

The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the control module to calculate the air-to-fuel ratio sooner.

P0133, P0153, P1133, or P1153

  1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
  2. The engine coolant temperature (ECT) is greater than 60°C (140°F).
  3. The intake air temperature (IAT) is warmer than -40°C (-40°F).
  4. The ignition voltage is between 10-32 V.
  5. The fuel level is greater than 10 percent.
  6. The engine run time is greater than 160 s.
  7. The engine speed is between 1,200-3,000 RPM.
  8. The barometric (BARO) pressure is greater than 70 kPa.
  9. The mass airflow (MAF) is between 20-55 g/s.
  10. The fuel system is in Closed Loop.
  11. The throttle position (TP) is greater than 5 percent.
  12. The DTCs run once per drive cycle when the above conditions are met.

P013A P013C, P013E, or P014A

  1. Before the ECM can report DTC P013A, or P013C failed, DTCs P013E, P014A, P2270, and P2272 must run and pass.
  2. Before the ECM can report DTC P013E, or P014A failed, DTCs P2270 and P2272 must run and pass.
  3. DTCs P0030, P0036, P0053, P0054, P0101, P0102, P0103, P0106, P0107, P0108, P0120, P0121, P0122, P0123, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P013A, P013B, P013E, P013F, P0140, P0141, P0171, P0172, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0300, P0442, P0443, P0446, P0449, P0455, P0496, P1133, P1174, P1516, P2101, P2119, P2135, P2176, P2270, P2271, P2A00 are not set.
  4. The ignition voltage is between 10-32 V.
  5. The fuel level is greater than 10 percent.
  6. The engine run time is equal to or greater than 5 minutes.
  7. The accelerator pedal (APP) is steady.
  8. The DTCs run once per ignition cycle, during decel fuel cut-off (DFCO), when the above conditions are met.

P013B P013D, P013F, or P014B

  1. Before the ECM can report DTC P013B, or P013D failed, DTCs P013A, P013C, P013E, P013F, P014A, P014B, P2270, P2271, P2272, and P2273 must run and pass.
  2. Before the ECM can report DTC P013F, or P014B failed, DTCs P013A, P013C, P013E, P014A, P2270, P2271, P2272, and P2273 must run and pass.
  3. DTCs P0030, P0036, P0053, P0054, P0101, P0102, P0103, P0106, P0107, P0108, P0120, P0121, P0122, P0123, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P013A, P013B, P013E, P013F, P0140, P0141, P0171, P0172, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0300, P0442, P0443, P0446, P0449, P0455, P0496, P1133, P1174, P1516, P2101, P2119, P2135, P2176, P2270, P2271, P2A00 are not set.
  4. The ignition voltage is between 10-32 V.
  5. The fuel level is greater than 10 percent.
  6. The engine run time is equal to or greater than 5 minutes.
  7. The DTCs run once per ignition cycle when the above conditions are met.

P0133 or P0153

  1. The ECM detects that the HO2S 1 rich-to-lean or lean-to-rich average response time is greater than a calibrated value.
  2. The DTCs set within 100 s when the above condition is met.

P013A or P013C

The ECM detects that the accumulated mass air flow monitored during rich-to-lean transitions between 450-150 mV is greater than a calibrated value.

P013B or P013D

The ECM detects that the accumulated mass air flow monitored during lean-to-rich transitions between 350-650 mV is greater than a calibrated value.

P013E or P014A

The ECM detects that the O2 sensor voltage has not decreased below 450 mV within a calibrated value of accumulated air flow.

P013F or P014B

The ECM detects that the O2 sensor voltage has not increased above 350 mV within a calibrated value of accumulated air flow.

P1133 or P1153

  1. The ECM detects that the HO2S 1 rich-to-lean counts, or the lean-to-rich counts are less than a calibrated value.
  2. The DTCs set within 100 s when the above condition is met.

DTCs P0133, P013A, P013B, P013C, P013D, P013E, P013F, P014A, P014B, P0153, P1133, and P1153 are Type B DTCs.

DTCs P0133, P013A, P013B, P013C, P013D, P013E, P013F, P014A, P014B, P0153, P1133, and P1153 are Type B DTCs.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the DTC information with a scan tool. Verify no HO2S heater DTCs are set. If a HO2S heater DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. Verify none of the following conditions exist: Lean or rich fuel injectors-Refer to «Fuel Injector Diagnosis (LC8\FHZ)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (J 39021 or Tech 2)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (CH47976)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (LC8\K07)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) Water intrusion in the HO2S harness connector Low or high fuel system pressure-Refer to «Fuel System Diagnosis (Without FPCM)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (LC8\K07\UFP)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (LC8\FHZ)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (FPCM)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (LC8\K07\UFM)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) Fuel that is contaminated-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) Fuel saturation of the evaporative emission (EVAP) canister Exhaust leaks near the HO2S Engine vacuum leaks Engine oil consumption-Refer to «Oil Consumption Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-48l-l20-53l-lmf-or-60l-l96-lc8-diagnostic-information-and-procedures__oil-consumption-diagnosis) Engine coolant consumption-Refer to «Loss of Coolant»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) If you find any of the above conditions, repair as necessary.
  3. If all conditions test normal, test or replace the appropriate B52 HO2S.
  4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  3. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  4. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 2»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  5. Perform the scan tool Heated Oxygen Sensor Resistance Learn Reset after replacing a HO2S.
  6. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
HO2S High SignalP0131, P0137, P0151, P0157P013C, P013D, P0131, P0132, P0133, P0134, P0137, P013A, P013B, P013E, P013F, P0140, P014A, P014B, P0151, P0152, P0153, P0154, P0157, P0160, P1133, P1153P013A, P013B, P013C, P013D, P013E, P013F, P0132, P0134, P0138, P0140, P014A, P014B, P0152, P0154, P0158, P0160P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P013C, P013D, P0133, P0134, P013A, P013B, P013E, P013F, P0140, P014A, P014B, P0153, P0154, P0160, P1133, P1153, P2A00, P2A03
HO2S Low SignalP0131, P0132, P0133, P0134, P0138, P013A, P013B, P013E, P013F, P0140, P014A, P014B, P0151, P0152, P0153, P0154, P0158, P0160, P1133P013C, P013D, P0131, P0132, P0133, P0134, P0138, P013A, P013B, P013E, P013F, P0140, P014A, P014B, P0151, P0152, P0153, P0154, P0158, P0160, P1133, P1153P0134, P0138, P0140, P0154, P0158, P0160
CircuitShort to GroundOpenShort to Voltage
Parameter Normal Range: 200-800 mV
HO2S High Signal0 mVApproximately 470 mVApproximately 1,100 mV
HO2S Low Reference455 mVApproximately 450 mVApproximately 445 mV

HO2S Bank 1 or 2 Sensor 1 or 2 Voltage

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,275 mV. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.

The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the control module to calculate the air-to-fuel ratio sooner.

  1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
  2. The ignition 1 voltage is between 10-32 V.
  3. The engine run time is greater than 300 s.
  4. The fuel system is in Closed Loop.
  5. The DTCs run continuously when the above conditions are met.

P0134 or P0154

The ECM detects that the HO2S 1 voltage is between 350-550 mV for at least 50 s.

P0140 or P0160

The ECM detects that the HO2S 2 voltage is between 410-490 mV for at least 74 s.

DTCs P0134, P0140, P0154, and P0160 are Type B DTCs.

DTCs P0134, P0140, P0154, and P0160 are Type B DTCs.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the DTC information with a scan tool. Verify no HO2S heater DTCs are set. If a HO2S heater DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. Run the engine for more than 5 minutes.
  3. Engine idling at operating temperature, observe the appropriate HO2S parameter with a scan tool. Verify the following: The HO2S Bank 1 or 2 Sensor 1 value should vary from below 200 mV to above 800 mV and respond to fueling changes. The HO2S Bank 1 or 2 Sensor 2 value should fluctuate at less than 380 mV or greater than 520 mV. The values should not remain within 380 mV and 520 mV.
  4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate B52 HO2S. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference circuit terminal A and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
  3. Ignition ON, verify the appropriate scan tool B52 HO2S parameter is approximately 450 mV. If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM. If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
  4. Install a 3 A fused jumper wire between the signal circuit terminal B and ground. Verify the appropriate scan tool B52 HO2S parameter is less than 60 mV. If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
  5. If all circuits test normal, replace the appropriate B52 HO2S.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  3. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  4. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 2»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  5. Perform the scan tool Heated Oxygen Sensor Resistance Learn Reset after replacing a HO2S.
  6. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. The ECM monitors the heated oxygen sensor (HO2S) signal voltage and adjusts the fuel delivery based on the signal voltage while in Closed Loop. A change made to the fuel delivery changes the long and short term fuel trim (FT) values. The short term FT values change rapidly in response to the HO2S voltage signals. These changes fine tune the engine fueling. The long term FT makes coarse adjustments in order to maintain an optimum air/fuel ratio. The ideal FT values are around zero percent. A positive FT value indicates that the ECM is adding fuel in order to compensate for a lean condition. A negative FT value indicates that the ECM is reducing the amount of fuel in order to compensate for a rich condition.

  1. DTCs P0030, P0050, P0053, P0059, P0101, P0102, P0103, P0106, P0107, P0108, P012B, P012C, P012D, P0131, P0132, P0133, P0134, P0135, P0151, P0152, P0153, P0154, P0155, P015A, P015B, P015C, P015D, P0178, P0179, P0201-P0206, P0300, P0301-P0306, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P0506, P0507, P1133, P1153, P2227, P2228, P2229, or P2269 are not set.
  2. The engine is in closed loop status.
  3. The catalyst monitor intrusive test, post O2 diagnosis intrusive test, device controls, and EVAP diagnosis leak test are not active.
  4. The engine coolant temperature (ECT) is between -40 and +150°C (-40 and +302°F).
  5. The intake air temperature (IAT) is between -20 and +150°C (-4 and 302°F).
  6. The manifold absolute pressure (MAP) is between 10-255 kPa (1.45-37 psi).
  7. The engine speed is between 375-7,000 RPM.
  8. The mass air flow (MAF) is between 1-510 g/s.
  9. The barometric pressure (BARO) is greater than 70 kPa (10.2 psi).
  10. The fuel level is greater than 10 percent.
  11. This diagnostic runs continuously when the above conditions have been met.
  1. The average long term FT weighted average value is greater or less than a calibrated value.
  2. The above condition is present for approximately 3 minutes after the Conditions for Running the DTC have been met.

DTCs P0171, P0172, P0174, and P0175 are Type B DTCs.

DTCs P0171, P0172, P0174, and P0175 are Type B DTCs.

  1. Allow the engine to reach operating temperature. With the engine running, observe the HO2S parameter with a scan tool. The HO2S value should vary from approximately 40 mV to approximately 900 mV, and respond to fueling changes.
  2. The normal Short Term FT and Long Term FT parameters should be between +10 and -10 percent the optimum with the engine running at operating temperature.
  3. A fuel system delivery condition causes this DTC to set. Thoroughly inspect all items that cause a rich or a lean condition. Refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  4. Any un-metered air into the engine causes this DTC to set. Thoroughly inspect all areas of the engine for vacuum leaks.
  5. A MAF sensor condition can cause this DTC without setting a MAF DTC. If there is a MAF sensor condition, the MAF sensor parameters will appear to be within range.
  6. Inspect the air filter for being the correct one for this application. Make sure that the engine oil fill cap is in place, and that it is tight. Verify that the engine oil dip stick is fully seated.
  7. Certain aftermarket air filters may cause a DTC to set.
  8. Certain aftermarket induction systems or modifications to the air induction system may cause a DTC to set.
  9. Certain aftermarket exhaust system components may cause a DTC to set.

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Engine running, observe the DTC information with a scan tool. Verify there are no HO2S DTCs set. If any DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. Ignition ON, engine OFF, verify that the Manifold Absolute Pressure (MAP) Sensor parameter is within the range specified for your altitude. Refer to «Altitude Versus Barometric Pressure»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-specifications__altitude-versus-barometric-pressure) . If not within the specified range, refer to «DTC P0106»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  3. Engine idling, verify the Mass Air Flow Sensor parameter is within 2-6 g/s. If not within the specified range, refer to «DTC P0101»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) , or «DTC P0102 or P0103»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  4. Engine at normal operating temperature, verify the scan tool Long Term FT parameter is between -24.5 to +31.5 percent. If not within the specified range, verify none of the conditions listed below exist: P0171 or P0174 Vacuum hoses split, kinked, or improperly connected Insufficient fuel in the tank Low fuel pressure. Refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Fuel contamination. Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Malfunctioning fuel injectors. Refer to «Fuel Injector Diagnosis (CH47976)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (J39021 or Tech 2)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Missing, restricted, or leaking exhaust components. Refer to «Symptoms - Engine Exhaust»(/chevrolet/express-g3500/2013-2013/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) . Vacuum leaks at the intake manifold, the throttle body, or the injector O-rings Leaks in the air induction system or the air intake ducts Missing air filter element Cracked evaporative emissions canister Evaporative pipes obstructed or leaking Leaks in the crankcase ventilation system. Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) . P0172 or P0175 Collapsed or restricted air intake duct Dirty or restricted air filter Objects blocking the throttle body Excessive fuel in the crankcase Improper operation of the evaporative emissions control system Excessive fuel pressure. Refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Missing, restricted, or leaking exhaust components. Refer to «Symptoms - Engine Exhaust»(/chevrolet/express-g3500/2013-2013/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) . Malfunctioning fuel injectors. Refer to «Fuel Injector Diagnosis (CH47976)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (J39021 or Tech 2)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Fuel contamination. Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . If a condition is found, repair as necessary If no condition is found, test the engine for a mechanical condition. Refer to «Symptoms - Engine Mechanical»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) .
  5. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Perform the Diagnostic Repair Verification after completing the repair.

Reset the fuel trim after completing the repair.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Ignition Voltage 1P0201, P0202, P0203, P0204, P0205, P0206, P0300P0201, P0202, P0203, P0204, P0205, P0206, P0300
Fuel Injector 1 ControlP0201P0201P0201
Fuel Injector 2 ControlP0202P0202P0202
Fuel Injector 3 ControlP0203P0203P0203
Fuel Injector 4 ControlP0204P0204P0204
Fuel Injector 5 ControlP0205P0205P0205
Fuel Injector 6 ControlP0206P0206P0206

The engine control module (ECM) enables the appropriate fuel injector pulse for each cylinder. Ignition voltage is supplied to the fuel injectors. The ECM controls each fuel injector by grounding the control circuit via a solid state device called a driver. The ECM monitors the status of each driver.

  1. The engine is running.
  2. The ignition voltage is greater than 11 V.
  3. DTC P0201-P0206 runs continuously when the above conditions are met.

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 2 s.

DTCs P0201, P0202, P0203, P0204, P0205, and P0206 are Type B DTCs.

DTCs P0201, P0202, P0203, P0204, P0205, and P0206 are Type B DTCs.

Performing the Fuel Injector Diagnosis may help isolate an intermittent condition. Refer to Fuel Injector Diagnosis (CH47976) , Fuel Injector Diagnosis (J39021 or Tech 2) .

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 34730-375 Injector Test Lamp

  1. Engine idling, observe the following control circuit status parameters for each fuel injector: Cyl 1-8 Injector Ckt Short Gnd Test Status Cyl 1-8 Injector Ckt Open Test Status Cyl 1-8 Injector Ckt Short Volts Test Status Each parameter should display OK or Not Run.
  2. Engine running, observe the DTC information with a scan tool. DTC P0201, P0202, P0203, P0204, P0205 or P0206 should not set.
  3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition OFF, disconnect the fuel injector harness connector.
  2. Ignition ON, verify that a test lamp illuminates between the affected ignition 1 voltage circuit and ground. If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition 1 voltage circuit fuse is open, test all components connected to the ignition voltage circuit and replace as necessary.
  3. Connect the J 34730-375 injector test lamp between the affected control circuit and the affected ignition 1 voltage circuit.
  4. Command the fuel injector ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
  5. If all circuits test normal, test or replace the fuel injector.

Note. The engine coolant temperature (ECT) sensor must be between 10-32°C (50-90°F) for an accurate measurement.

Measure for 11-14 ohms between the terminals of the fuel injector.

  1. If not within the specified range, replace the fuel injector.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Fuel Injector Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Battery Voltage - Relay Switch Side12
Fuel Pump Supply Voltage123
Fuel Pump Relay ControlP0230P0230P0230
Fuel Pump Relay GroundP0230
Fuel Pump Ground2
1 Open fuel pump fuse, cranks no start 2 Cranks no start 3 Fuel pump operates continuously, then discharged battery

The engine control module (ECM) enables the fuel pump relay when the ignition switch is turned ON. The ECM will disable the fuel pump relay within 2 seconds unless the ECM detects ignition reference pulses. The ECM continues to enable the fuel pump relay as long as ignition reference pulses are detected. The ECM disables the fuel pump relay within 2 seconds if ignition reference pulses cease to be detected and the ignition remains ON.

The ECM monitors the voltage on the fuel pump relay control circuit. If the ECM detects an incorrect voltage on the fuel pump relay control circuit, a fuel pump relay control DTC sets.

  1. The ignition voltage is between 9-18 volts.
  2. DTC P0230 runs continuously when the above conditions are met.
  1. The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match.
  2. The above condition is met for a minimum of 2.5 seconds.

DTC P0230 is a Type B DTC.

DTC P0230 is a Type B DTC.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 43244 Relay Puller Pliers

IMPORTANTAn open or a short to voltage in the control circuit will cause both the Ckt. Open Test Status and the Ckt. Short Volts Test Status parameters to display Fault.
  1. Ignition ON, command the fuel pump relay ON and OFF with a scan tool while observing the following control circuit status parameters: Fuel Pump Relay Ckt. Short Gnd Test Status Fuel Pump Relay Ckt. Open Test Status Fuel Pump Relay Ckt. Short Volts Test Status
  2. Each parameter should toggle between OK and Not Run or Not Run and OK.
  1. Ignition OFF, disconnect the fuel pump relay.
  2. Ignition ON, verify that a test lamp illuminates between the ground circuit terminal and B+. If the test lamp does not illuminate, test the ground circuit for a short to voltage or an open/high resistance.
  3. Verify that a test lamp does not illuminate between the ground circuit terminal and the control circuit terminal. If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  4. Remove the test lamp.
  5. Command the fuel pump relay ON with a scan tool. Verify the scan tool fuel pump relay Ckt. Short Grnd Test Status parameter is OK. If not the specified value, test the fuel pump relay control circuit for a short to ground. If the circuit tests normal, replace the ECM.
  6. Install a 3A fused jumper wire between the fuel pump relay control circuit terminal and the ground circuit terminal. Command the fuel pump ON with a scan tool. Verify the scan tool fuel pump relay Ckt. Short Grnd Test Status parameter is Fault. If not the specified value, test the fuel pump relay control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  7. If all circuits test normal, test or replace the fuel pump relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Relay Replacement (Within an Electrical Center)»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) , «Relay Replacement (Attached to Wire Harness)»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The engine control module (ECM) uses information from the crankshaft position (CKP) sensor in order to determine when an engine misfire is occurring, and uses information from the camshaft position (CMP) sensor in order to determine which cylinder is misfiring. By monitoring variations in the crankshaft rotation speed for each cylinder, the ECM is able to detect individual misfire events. If the ECM detects a misfire rate sufficient to cause emission levels to exceed mandated standards, DTC P0300 sets. Under certain driving conditions, a misfire rate can be high enough to cause the catalytic converter to overheat, possibly damaging the converter. The malfunction indicator lamp (MIL) will flash ON and OFF when catalytic converter overheating conditions are present and DTC P0300 is set. DTCs P0301-P0306 corresponds to cylinders 1-6. If the ECM is able to determine that a specific cylinder is misfiring, the DTC for that cylinder will also be set.

  1. DTC P0010, P0011, P0016, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0122, P0123, P0128, P0220, P0222, P0223, P0335, P0336, P0606, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, P3401, P3425, P3441, and P3449 are not set.
  2. The engine speed is between 375-5,800 RPM and DTC P0315 is not set. OR
  3. The engine speed is greater than 1,000 rpm and DTC P0315 is set.
  4. The ignition voltage is between 9-18 volts.
  5. The engine coolant temperature (ECT) is between -7 and +130°C (+19 and +266°F).
  6. If the ECT is less than -7°C (+19°F) at startup this diagnostic will not run until the ECT is more than +21°C (+69°F).
  7. The fuel level is more than 10 percent.
  8. The antilock brake system (ABS) and the traction control system (TCS) are not active or detecting rough road.
  9. The power management is not active.
  10. The ECM is not in fuel shut-off, or decel fuel cut-off mode.
  11. Excessive drive wheel slip is not detected.
  12. Power Take Off (PTO) is disabled.
  13. Cylinder Deactivation is not in progress.
  14. A manual transmission with a throttle position less than 95 percent.
  15. DTC P0300-P0306 runs continuously when the above conditions are met.

The ECM is detecting a crankshaft rotation speed variation indicating a misfire sufficient to cause emission or catalytic converter damaging levels to exceed mandated standards.

  1. DTCs P0300-P0306 are Type B DTCs
  2. When the MIL is flashing the fuel injector may be disabled for the misfiring cylinder to protect the catalytic converter.
  3. Depending on the conditions that set the DTC the engine may go into open loop.
  1. DTCs P0300-P0306 are Type B DTCs.
  2. The DTC must pass under the same operating conditions that were present when the DTC failed.
  1. A misfire may only occur when the engine is operating under a load or when the engine is cold.
  2. A high resistance condition on any ignition control (IC) circuit can cause an engine misfire DTC P0300-P0306 to set, without setting an IC circuit DTC P0351-P0353.
  3. This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to «Battery Inspection/Test»(/chevrolet/express-g3500/2013-2013/remont/charging-system/#battery-charging-system-and-starting-system) .
  4. A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect the following for possible sources of vibration: A tire or wheel that is out of round or balance Variable thickness brake rotors An unbalanced drive shaft Certain rough road conditions A damaged accessory drive component or belt A damaged reluctor wheel The Crankshaft Position System Variation Learn procedure may need to be performed.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)
  5. «Powertrain Component Views»(/chevrolet/express-g3500/2013-2013/remont/electrical-component-locations/#wiring-systems-and-power-management-component-locator-powertrain-component-views)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 26792 HEI Spark Tester

  1. Verify that no other DTCs are set. If a DTCs is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. Engine idling, verify there is no abnormal engine noise. If there is abnormal engine noise, refer to «Symptoms - Engine Mechanical»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) .
  3. Observe the Misfire Current Counters with a scan tool. The Misfire Current Counters should not be incrementing. A random misfire, across one or more cylinders that are not steadily incrementing may be normal for this engine.
  4. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.
IMPORTANTYou must perform the Circuit/System Verification first.
  1. Verify that the following conditions do not exist: The fuel injector wire harness electrical connectors are connected to the improper fuel injectors. Refer to «Engine Controls Schematics»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-wiring-schematic-diagrams) . Engine vacuum leaks Fuel pressure that is too low or too high-Refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Contaminated fuel-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Restricted exhaust system-Refer to «Restricted Exhaust»(/chevrolet/express-g3500/2013-2013/remont/exhaust/#engine-exhaust-system) .
  2. Measure the resistance of the spark plug wire, and verify the condition of the spark plug wire. Refer to «Ignition System Specifications»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-specifications__ignition-system-specifications) , and «Spark Plug Wire Inspection»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__spark-plug-wire-inspection) . If the resistance value is not within the specified range, or does not pass the inspection, replace the spark plug wire.
  3. Reinstall the spark plug wire to the ignition module/coil assembly.
  4. Install the J 26792 HEI spark tester to the spark plug wire boot.
  5. Attempt to start the engine and observe the J 26792 HEI spark tester. The spark plug tester should spark. If there is no spark, refer to «Electronic Ignition System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  6. Ignition OFF, remove the spark plug from the misfiring cylinder. Verify that the following conditions do not exist with the spark plug: Gas, coolant, or oil fouled Cracked, worn, or incorrectly gapped-Refer to «Spark Plug Inspection»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__spark-plug-inspection) . If there is a condition with the spark plug, replace the spark plug.
  7. Exchange the suspected spark plug with another cylinder that is operating correctly.
  8. Operate the engine under the conditions in which the misfire occurred, this may include putting the engine under a load or allowing the engine to return to a cold condition. Observe the Misfire Current Counters with a scan tool. The misfire should not follow the spark plug exchange. If the misfire follows with the spark plug, replace the spark plug.
  9. If all conditions test normal, test or inspect for the following: A lean or rich fuel injector, refer to «Fuel Injector Diagnosis (CH47976)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (J39021 or Tech 2)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . An engine mechanical condition, refer to «Symptoms - Engine Mechanical»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) .
  1. «Ignition Coil Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Spark Plug Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  3. «Spark Plug Wire Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)

Repair Verification

  1. Install any components the have been removed or replaced during diagnosis.
  2. Perform any adjustments, programming or setup procedures that are required when a component is removed or replaced.
  3. Clear the DTCs.
  4. Turn OFF the ignition for 60 seconds.
  5. If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) and perform the appropriate diagnostic procedure.
  6. To verify that the performance of the catalytic converter has not been affected by the condition that set this DTC, perform the repair verification for DTCs P0420 and P0430. Refer to «DTC P0420 or P0430»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The crankshaft position (CKP) system variation learn feature is used to calculate reference period errors caused by slight build tolerance variation in the CKP sensor, crankshaft, and CKP sensor position. The calculated error allows the engine control module (ECM) to accurately compensate for reference period variations. This enhances the ability of the ECM to detect misfire events over a wide range of engine speeds and load conditions. The ECM stores the Crankshaft Position System Variations values after a learn procedure has been performed. If the actual crankshaft position variation is not stored within the CKP compensating value look up table, then DTC P0300 may set. If the CKP system variation values are not stored in the ECM memory, or a proper ECM power down does not occur after completing the CKP Learn Procedure, then DTC P0315 sets.

The diagnostic runs continuously.

The ECM detects that the CKP system variation values are not stored in memory.

DTC P0315 is a Type A code.

DTC P0315 is a Type A code.

This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test .

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

IMPORTANTThe CKP System Variation Learn Procedure may have to be repeated up to 5 times before the procedure is learned.

Perform the CKP System Variation Learn Procedure. Refer to Crankshaft Position System Variation Learn . The scan tool should display Learned this Ignition.

  1. If the CKP System Variation Learn Procedure cannot be performed successfully, inspect for the following conditions
  1. Any worn crankshaft main bearings
  2. A damaged or misaligned reluctor wheel
  3. Excessive crankshaft runout
  4. A damaged crankshaft-Refer to «Crankshaft and Bearing Cleaning and Inspection»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3__crankshaft-and-bearing-cleaning-and-inspection) .
  5. Interference in the signal circuit of the CKP sensor
  6. The ignition switch is left in the ON position, until the battery is discharged.
  7. An ECM power disconnect, with the ignition ON, that may have erased the CKP system variation values and set DTC P0315
  8. Any debris between the CKP sensor and the reluctor wheel
  9. An internal ECM condition that is unable to complete the learn procedure, which will require an ECM replacement

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «K20 Engine Control Module: Programming and Setup (Gasoline Engines)»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__k20-engine-control-module-programming-and) , «K20 Engine Control Module: Programming and Setup (LGH)»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__k20-engine-control-module-programming-and)
  2. «Engine Control Module Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Knock Sensor SignalP0327, P0328, P0332, P0333P0325, P0330P0327, P0328, P0332, P0333P0326

The knock sensor (KS) system enables the engine control module (ECM) to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The ECM monitors 2 separate KS, one on each side of the engine block. Each KS produces an AC voltage that varies, depending on the vibration levels detected during engine operation. The ECM receives the KS signal through 2 isolated signal circuits for each KS. The ECM adjusts the spark timing based on the amplitude and frequency of each KS signal. The ECM learns a minimum noise level for each sensor at idle speeds, and uses calibrated noise level value for the rest of the RPM range. The ECM should monitor a normal KS signal within the noise channel.

P0324

  1. DTC P0325, P0326, P0327, P0328, P0330, P0332, or P0333 is not set.
  2. The engine speed is greater than 300 RPM.
  3. The engine air flow is greater than 50 mg/cylinder.
  4. DTC P0324 runs continuously when the above conditions are met.

P0325 and P0330

  1. DTC P0324, P0325, P0326, P0327, P0328, P0330, P0332, or P0333 is not set.
  2. The engine speed is greater than 400 RPM.
  3. The engine coolant temperature (ECT) is greater than -40°C (-40°F).
  4. The engine run time is greater than 2 minutes.
  5. The power take-off (PTO) is not active.
  6. DTCs P0325 and P0330 run continuously when the above conditions are met.

P0326

  1. DTC P0068, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0606, P1516, P2101, P2135, or P2176 is not set.
  2. The engine speed is greater than 400 RPM.
  3. The manifold air pressure (MAP) is greater than 10 kPa.
  4. The power take-off (PTO) is not active.
  5. DTC P0326 runs continuously when the above conditions are met.

P0327, P0328, P0332, and P0333

  1. DTC P0112, P0113, P0116, P0117, P0118, or P0128 is not set.
  2. The engine coolant temperature (ECT) is greater than -40°C (-40°F).
  3. The engine oil temperature is less than 256°C (492.8°F).
  4. The engine run time is greater than 2 minutes.
  5. DTCs P0327, P0328, P0332, and P0333 run continuously when the above conditions are met.

P0324

The ECM has detected an internal circuitry fault.

P0325 or P0330

The KS signal circuits are open or shorted together for 5 seconds.

P0326

  1. The KS signal indicates an engine knock is present.
  2. The ECM has commanded the spark retard to a value which is more than the calibrated valve, for a specific engine load and speed.
  3. The above conditions exist for more than 5 seconds.

P0327, P0328, P0332, and P0333

The KS signal circuits are shorted to voltage or ground.

DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0332, and P0333 are Type B codes.

DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0332, and P0333 are Type B codes.

  1. Inspect the KS for physical damage. A KS that is drop or damage may cause a DTC to set.
  2. Inspect the KS for proper installation. A KS that is loose or over torqued may cause a DTC to set.
  3. The KS mounting surface should be free of burs, casting flash, and foreign material.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

P0324

IMPORTANTIf DTCs P0325, P0327, P0328, P0330, P0332, or P0333 are also set, diagnose those DTCs first.

DTC P0324 indicates an internal control module circuitry failure. Replace the ECM.

P0325, P0327, P0328, P0330, P0332, or P0333

  1. Ignition ON, engine OFF.
  2. Disconnect the appropriate KS harness connector.
  3. Measure for 2-3 volts between each of the following circuits and ground on the ECM side of the harness connector. The KS signal circuit terminal A The KS low reference circuit terminal B If less than the specified range, test the circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the ECM. If greater than the specified range, test the circuits for a short to voltage. If the circuits test normal, replace the ECM.
  4. If all circuits test normal, replace the KS.

P0326

  1. Inspect for a loose or broken engine mount, engine mounted accessory, or accessory mounting bracket.
  2. Inspect for excessive engine mechanical noise. Refer to «Symptoms - Engine Mechanical»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) .
  1. Connect a DMM to the KS signal circuit and to the KS low reference circuit at the KS.
  2. Set the DMM to the 400 mv AC hertz scale and wait for the DMM display to stabilize at 0 Hz.
  3. Tap on the engine block with a non-metallic object near the KS while observing the signal indicated on the DMM.
  4. The DMM should display a fluctuating frequency while tapping on the engine block.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «K20 Engine Control Module: Programming and Setup (Gasoline Engines)»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__k20-engine-control-module-programming-and) , «K20 Engine Control Module: Programming and Setup (LGH)»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__k20-engine-control-module-programming-and)
  2. «Engine Control Module Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  3. «Knock Sensor 1 Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  4. «Knock Sensor 2 Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
5 V ReferenceP0335, P0651P0335P0651P0336
SignalP0335P0335P0335P0336
Low ReferenceP0335P0335P0336

The crankshaft position sensor circuits consist of an engine control module (ECM) supplied 5 V reference circuit, low reference circuit, and an output signal circuit. The crankshaft position sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 58-tooth reluctor wheel on the crankshaft. Each tooth on the reluctor wheel is spaced at 60-tooth spacing, with 2 missing teeth for the reference gap. The crankshaft position sensor produces an ON/OFF DC voltage of varying frequency, with 58 output pulses per crankshaft revolution. The frequency of the crankshaft position sensor output depends on the velocity of the crankshaft. The crankshaft position sensor sends a digital signal, which represents an image of the crankshaft reluctor wheel, to the ECM as each tooth on the wheel rotates past the crankshaft position sensor. The ECM uses each crankshaft position signal pulse to determine crankshaft speed and decodes the crankshaft reluctor wheel reference gap to identify crankshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM also uses crankshaft position sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and to detect cylinder misfire.

P0335 Condition 1

  1. The starter is engaged and the engine control module detects crankshaft position sensor pulses. Or
  2. DTCs P0101, P0102 and P0103 are not set. And
  3. The airflow into the engine is greater than 3 g/s.

Condition 2

  1. The engine is running.
  2. DTC P0651 is not set.

Condition 3

  1. The engine is running or the starter is engaged.
  2. DTCs P0365, P0366, P0641, or P0651 are not set.

P0336 Condition 1

  1. DTCs P0101, P0102 and P0103 are not set.
  2. The starter is engaged and the engine control module detects crankshaft position sensor pulses.
  3. The airflow into the engine is greater than 3 g/s.

Condition 2

  1. The engine is running and the starter is not engaged.
  2. DTC P0651 is not set.

Condition 3

  1. Engine speed is greater than 450 RPM.
  2. DTCs P0335 or P0651 is not set.
  3. The airflow into the engine is greater than 3 g/s.

Condition 4

  1. The engine is running or the starter is engaged.
  2. DTCs P0340, P0341, P0641, or P0651 is not set.

The DTCs run continuously once the above conditions are met.

P0335 Condition 1

Engine cranking and the ECM does not detect a crankshaft position sensor pulse for greater than 4 s.

Condition 2

Engine running and the ECM does not detect a crankshaft position sensor pulse for greater than 0.3 s.

Condition 3

Engine running and the ECM does not detect a crankshaft position sensor pulse for 2 out of 10 engine revolutions.

P0336 Condition 1

The ECM detects less than 53 or greater than 65 crankshaft position sensor pulses, during 8 out of 10 engine revolutions.

Condition 2

Engine running and the ECM detects that 25 or more crankshaft resynchronizations have occurred within 20 s.

Condition 3

Engine running and the ECM does not detect crankshaft synchronization for greater than 0.4 s.

  1. DTCs P0335 and P0336 are Type B DTCs.
  2. An engine driveability issue occurs after the first failure.
  3. The camshaft position sensor is used to determine engine position.
  4. The camshaft actuators are commanded to the parked position.

DTCs P0335 and P0336 are Type B DTCs.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify DTC P0651 is not set. If the DTC is set Refer to «DTC P0641 or P0651»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . If the DTC is not set
  3. Engine running.
  4. Verify the scan tool Crankshaft Position Active Counter parameter increments. If the counter does not increment Refer to Circuit/System Testing. If the counter increments
  5. Verify the scan tool Crankshaft Position Resync Counter parameter displays 0 counts and the engine does not stumble or stall while moving the related harness/connectors of the Crankshaft Position (CKP) Sensor. If greater than 0 counts and the engine stumbles or stalls Refer to Circuit/System Testing. If 0 counts and the engine does not stumble or stall
  6. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  7. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  8. All OK.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the Crankshaft Position Sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference circuit terminal B and ground. If 5 ohms or greater Ignition OFF, disconnect the X2 harness connector at the Engine Control Module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If 2 ohms or less, replace the Engine Control Module. If less than 5 ohms
  3. Ignition ON.
  4. Test for 4.8-5.2 V between the 5 V reference circuit terminal A and ground. If less than 4.8 V Ignition OFF, disconnect the X2 harness connector at the Engine Control Module. Test for infinite resistance between the 5 V reference circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the 5 V reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the Engine Control Module. If greater than 5.2 V Ignition OFF, disconnect the X2 harness connector at the Engine Control Module, ignition ON. Test for less than 1 V between the 5 V reference and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the Engine Control Module. If between 4.8-5.2 V
  5. Test for 4.8-5.2 V between the signal circuit terminal C and ground. If less than 4.8 V Ignition OFF, disconnect the X2 harness connector at the Engine Control Module. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance. Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the Engine Control Module. If greater than 5.2 V Ignition OFF, disconnect the X2 harness connector at the Engine Control Module, ignition ON. Test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the Engine Control Module. If between 4.8-5.2 V
  6. Ignition OFF, connect a 3 A fused jumper wire to the signal circuit terminal C, ignition ON.
  7. Verify the scan tool Crankshaft Position Active Counter parameter increments while rapidly tapping the fused jumper wire end to ground. If the counter does not increment Replace the Engine Control Module. If the counter increments
  8. Verify DTC P0336 is not set. If the DTC is set Inspect for the conditions listed below: Excessive play or looseness of the Crankshaft Position Sensor or the reluctor wheel Improper installation of the Crankshaft Position Sensor Foreign material passing between the Crankshaft Position Sensor and the reluctor wheel Damaged reluctor wheel Excessive air gap between the Crankshaft Position Sensor and the reluctor wheel Engine oil for debris Timing chain, tensioner, and sprockets for wear or damage If any of the conditions above are found, repair as necessary. If all components test normal, replace the Crankshaft Position Sensor. If the DTC is not set
  9. Replace the Crankshaft Position Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Crankshaft Position Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
5 V ReferenceP0107, P0340, P0452, P0641P0340P0107, P0340, P0452, P0641
SignalP0340P0340P0340P0341
Low ReferenceP0340P0340

The camshaft position sensor each has 3 circuits consisting of an engine control module (ECM) supplied 5 V reference circuit, low reference circuit, and an output signal circuit. The camshaft position sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 4-tooth reluctor wheel attached to the camshaft. As each reluctor wheel tooth rotates past the camshaft position sensor, the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. The sensor returns a digital ON/OFF DC voltage pulse of varying frequency with 4 varying width output pulses per camshaft revolution that represent an image of the camshaft reluctor wheel. The frequency of the camshaft position sensor output depends on the velocity of the camshaft. The ECM decodes the narrow and wide tooth pattern to identify camshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM uses the camshaft position sensor to determine injector and ignition system synchronization. The camshaft position sensor is also used to determine camshaft to crankshaft relationship. The ECM also uses camshaft position sensor output information to determine the camshaft relative position to the crankshaft to control camshaft phasing and limp-home operation.

Condition 1

  1. The starter is engaged and the engine control module detects camshaft position sensor pulses. Or
  2. DTCs P0101, P0102 and P0103 are not set. And
  3. The airflow into the engine is greater than 3 g/s.

Condition 2

  1. The engine is running and the starter is not engaged.
  2. DTC P0651 is not set.

Condition 3

  1. Crankshaft is synchronized
  2. The starter is engaged and the engine is running.
  3. DTCs P0335, P0336, P0641, or P0651, are not set.

The DTCs run continuously once the above conditions are met.

Condition 1

  1. The engine is running and the ECM does not detect a camshaft position sensor pulse for greater than 5.5 s. OR
  2. The starter has been engaged and the ECM does not detect a camshaft position sensor pulse for greater than 4.0 s.

Condition 2

The ECM detects fewer than 4 camshaft position sensor pulses for greater than 3.0 s.

Condition 3

The ECM does not detect a camshaft position sensor pulse during the first 2 engine revolutions.

Condition 4

The ECM does not detect a camshaft position sensor pulse during 50 engine revolutions.

  1. DTCs P0340 and P0341 are Type B DTCs.
  2. The camshaft position actuator is commanded to the Home or Parked position.
  3. The ignition system defaults to a failed camshaft position sensor limp home mode.

DTCs P0340 and P0341 are Type B DTCs.

With a DTC set, the engine may crank for an extended period of time at start-up

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify DTC P0641 or P0651 is not set. If any of the DTCs are set Refer to «DTC P0641 or P0651»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . If none of the DTCs are set
  3. Engine running.
  4. Verify the scan tool Camshaft Position Active Counter parameter increments. If the counter does not increment Refer to Circuit/System Testing. If the counter increments
  5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  6. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  7. All OK.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate Camshaft Position Sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference circuit terminal B and ground. If 5 ohms or greater Ignition OFF, disconnect the X2 harness connector at the Engine Control Module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If 2 ohms or less, replace the Engine Control Module. If less than 5 ohms
  3. Ignition ON.
  4. Test for 4.8-5.2 V between the 5 V reference circuit terminal A and ground. If less than 4.8 V Ignition OFF, disconnect the X2 harness connector at the Engine Control Module. Test for infinite resistance between the 5 V reference circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance. Test for less than 2 ohms in the 5 V reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms , replace the Engine Control Module. If greater than 5.2 V Ignition OFF, disconnect the X2 harness connector at the Engine Control Module, ignition ON. Test for less than 1 V between the 5 V reference circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the Engine Control Module. If between 4.8-5.2 V
  5. Test for 4.8-5.2 V between the signal circuit terminal C and ground. If less than 4.8 V Ignition OFF, disconnect the X2 harness connector at the Engine Control Module. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance. Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the Engine Control Module. If greater than 5.2 V Ignition OFF, disconnect the X2 harness connector at the Engine Control Module, ignition ON. Test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the Engine Control Module. If between 4.8-5.2 V
  6. Verify DTC P0341 is not set. If the DTC is set Inspect for the conditions listed below: Excessive play or looseness of the Camshaft Position Sensor or the reluctor wheel Improper installation of the Camshaft Position Sensor Foreign material passing between the Camshaft Position Sensor and the reluctor wheel Damaged reluctor wheel Excessive air gap between the Camshaft Position Sensor and the reluctor wheel Engine oil for debris Timing chain, tensioner, and sprockets for wear or damage If any of the conditions above are found, repair as necessary. If all components test normal, replace the Camshaft Position Sensor. If the DTC is not set
  7. Replace the Camshaft Position Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Camshaft Position Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Ignition Voltage12
Ignition Coil 1 ControlP0300, P0351P0300, P0351P0300, P0351P0300, P0351
Ignition Coil 2 ControlP0300, P0352P0300, P0352P0300, P0352P0300, P0352
Ignition Coil 3 ControlP0300, P0353P0300, P0353P0300, P0353P0300, P0353
Low Reference
Ground3
1. The engine cranks but does not run and opens the fuse that supplies voltage to the ignition coils. 2. The engine cranks but does not run 3. The engine may still run

The ignition system on this engine uses an ignition control module. The engine control module (ECM) controls the spark event for each cylinder through the individual ignition coil control circuits. When the ECM commands the ignition control circuit ON, electrical current will flow through the primary winding of the ignition coil, creating a magnetic field. When a spark event is requested, the ECM will command the ignition control circuit OFF, interrupting current flow through the primary winding. The magnetic field created by the primary winding will collapse across the secondary coil windings, producing a high voltage across the spark plug electrodes. The ECM uses information from the crankshaft position sensor, and the camshaft position sensor for sequencing and timing of the spark events. The ECM monitors each ignition control circuit for improper voltage levels.

  1. The engine is cranking or running.
  2. Ignition voltage is greater than 5 V.

The DTCs run continuously when the above conditions are met.

The engine control module detects that the voltage command state of the driver and the actual state of the control circuit do not match.

DTCs P0351, P0352, and P0353 are Type B DTCs.

DTCs P0351, P0352, and P0353 are Type B DTCs.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Engine Running.
  2. Verify the scan tool parameters listed below do not display Malfunction: Ignition Coil 1-3 Control Circuit High Voltage Test Status Ignition Coil 1-3 Control Circuit Low Voltage Test Status Ignition Coil 1-3 Control Circuit Open Test Status If Malfunction is displayed Refer to Circuit/System Testing. If Malfunction is not displayed
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  4. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  5. All OK.
  1. Ignition OFF, disconnect the harness connector at the Ignition Control Module.
  2. Remove the fuel injector fuse.
  3. Connect a DMM between the appropriate Ignition Coil Module control circuit listed below and ground. Set the DMM to the DC Hz scale and utilize the Min-Max function: Terminal A Terminal B Terminal C
  4. Verify the DMM displays greater than 1.5 Hz while cranking the engine. If less than 1.5 Hz Ignition OFF, disconnect the X2 harness connector at the Engine Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms Ignition ON. Test for less than 1 V between the control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the Engine Control Module. If greater than 1.5 Hz
  5. Replace the Ignition Control Module.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Ignition Coil Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

A 3-way catalytic converter controls emissions of hydrocarbons, carbon monoxide (CO) and nitrogen oxide (NOx). The catalyst within the converter promotes a chemical reaction, which oxidizes the hydrocarbons and the CO that are present in the exhaust gas. This process converts the hydrocarbons and the CO into water vapor and carbon dioxide (CO2), and reduces the NOx, converting the NOx into nitrogen. The catalytic converter also stores oxygen. The ECM monitors this process by using a heated oxygen sensor (HO2S) that is in the exhaust stream after the 3-way catalytic converter. The HO2S 2 produces an output signal that the ECM uses to calculate the oxygen storage capacity of the catalyst. This indicates the ability of the catalyst to convert the exhaust emissions efficiently. The ECM monitors the efficiency of the catalyst by allowing the catalyst to heat, then wait for a stabilization period while the engine is idling. The ECM then adds and removes fuel while monitoring the HO2S 2. When the catalyst is functioning properly, the HO2S 2 response to the extra fuel is slow compared to the response of the HO2S 1, which is located before the 3-way catalytic converter. When the HO2S 2 response is near that of the HO2S 1, the oxygen storage capability and efficiency of the catalyst may be degraded below an acceptable threshold.

  1. Driving Conditions DTC P0030, P0031, P0036, P0037, P0038, P0068, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0120, P0121, P0122, P0123, P0125, P0128, P0130, P0131, P0132, P0133, P0134, P0135, P0136, P0137, P0138, P0140, P0141, P0171, P0172, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0300, P0315, P0326, P0327, P0336, P0340, P0341, P0442, P0446, P0452, P0453, P0455, P0496, P0500 (manual transmission only), P0502, P0506, P0507, P0601, P0602, P0606, P0641, P0722, P0723, P1133, P1134, P1516, P1621, P2135, P2138, or P2176 is not set. Engine has been running for more than 2 minutes. Vehicle has been driven at greater than 1,000 RPM with the mass air flow (MAF) greater than 18 g/s for greater than 30 s. Engine is in Closed Loop. Vehicle has Fuel Trim Learn enabled. Engine coolant temperature (ECT) is between 45-128°C (113-262°F). Barometric pressure (BARO) is greater than 70 kPa. Catalytic converter calculated temperature is at least 420°C (788°F). Intake air temperature (IAT) is between -20 and +85°C (-4 and +185°F). Battery voltage is greater than 11 V.
  2. Idle Conditions Vehicle speed is less than 3.2 km/h (2 mph). For automatic transmissions, the transmission is in Reverse, Drive, or Low. Throttle position is less than 2 %. Short term fuel trim is between -10 and +10 %. This diagnostic attempts one test during each valid idle period until a pass or fail decision has been reached when the above conditions have been met. This diagnostic attempts up to 8 completed tests during each drive cycle.

The ECM has determined the catalyst efficiency has degraded below a calibrated threshold.

DTCs P0420 and P0430 are Type A DTCs.

DTCs P0420 and P0430 are Type A DTCs.

Inspect for the conditions listed below, which may cause a catalyst to degrade

  1. Engine misfire
  2. High engine oil or high coolant consumption
  3. Retarded spark timing
  4. Weak or poor spark
  5. Lean fuel mixture
  6. Rich fuel mixture
  7. Damaged oxygen sensor or wiring harness

DTC Type Reference

Electrical Information Reference

  1. Ignition ON.
  2. Verify there are no other DTCs set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If a DTC is not set
  3. Operate the vehicle within the Conditions for Running the DTC.
  4. Verify the scan tool Catalyst Monitor Not At Idle Test Conditions Met parameter changes to Yes. If Yes is not displayed Refer to step 3. If Yes is displayed
  5. When the conditions are safe, stop and idle the vehicle in gear (If equipped with automatic transmission) or neutral (If equipped with manual transmission).
  6. Verify the Catalyst Monitor Test Result Bank 1 and Bank 2 parameters display Pass when performing the steps listed below: Apply the service brake. Monitor the scan tool Catalyst Monitor Test State parameter. When the parameter indicates Active, the Catalyst Monitor Test is running. NOTE: When the test has completed, the Catalyst Monitor Test Counter Bank 1 and Bank 2 parameters will increment by one and the Catalyst Monitor Test Result Bank 1 and Bank 2 parameters will indicate Passed, Failed or No Result. Continue to monitor the parameter. When the parameter indicates Inactive, the Catalyst Monitor Test has completed. If the Catalyst Monitor Test Result Bank 1 or Bank 2 parameter indicates No Result Repeat steps 3-6 until the Test Result parameters indicate Passed or Failed If the Catalyst Monitor Test Result Bank 1 or Bank 2 parameter indicates Failed Refer to Circuit /System Testing If the Catalyst Monitor Test Result Bank 1 and Bank 2 parameters indicate Pass
  7. All OK.
  1. Verify the conditions listed below do not exist with the appropriate catalytic converter: Dents Severe discoloration caused by excessive temperatures Road damage Internal rattles caused by damaged catalyst substrate Restrictions If a condition is found Replace the catalytic converter If no condition is found
  2. Verify the conditions listed below do not exist with the exhaust system: Leaks Physical damage Loose or missing hardware If a condition is found Repair or replace the component as necessary. If no condition is found
  3. Verify the conditions listed below do not exist with the appropriate B52B heated oxygen sensor 2: The HO2S is not at the correct torque Damage If a condition is found Replace the B52B heated oxygen sensor 2 or repair the condition as necessary. If no condition is found
  4. Test or replace the catalytic converter.

Note. A new converter with less than 100 miles on it may set DTC P0420 or P0430 due to out-gassing of the internal matting. Operating the vehicle at highway speeds for approximately 1 h may correct the condition.

  1. «Catalytic Converter Replacement (LGH)»(/chevrolet/express-g3500/2013-2013/remont/exhaust/#engine-exhaust-system)
  2. «Exhaust Leakage»(/chevrolet/express-g3500/2013-2013/remont/exhaust/#engine-exhaust-system__exhaust-leakage)
  3. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  4. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 2»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  5. Perform the HO2S Heater Learn procedure with a scan tool after replacing a Heated Oxygen Sensor.
  6. «Restricted Exhaust»(/chevrolet/express-g3500/2013-2013/remont/exhaust/#engine-exhaust-system)
  1. Install any components that have been removed or replaced during diagnosis.
  2. Perform any adjustments, programming or setup procedures that are required when a component is removed or replaced.
  3. Clear the DTCs with a scan tool.
  4. Turn OFF the ignition for 60 s
  5. Operate the vehicle within the Conditions for Running the DTC.
  6. Verify the scan tool Catalyst Monitor Not At Idle Test Conditions Met parameter changes to Yes. If Yes is not displayed Refer to step 5. If Yes is displayed
  7. When the conditions are safe, stop and idle the vehicle in gear (If equipped with automatic transmission) or neutral (If equipped with manual transmission).
  8. Verify the Catalyst Monitor Test Result Bank 1 and Bank 2 parameters display Pass when performing the steps listed below: Apply the service brake. Monitor the scan tool Catalyst Monitor Test State parameter. When the parameter indicates Active, the Catalyst Monitor Test is running. NOTE: When the test has completed, the Catalyst Monitor Test Counter Bank 1 and Bank 2 parameters will increment by one and the Catalyst Monitor Test Result Bank 1 and Bank 2 parameters will indicate Passed, Failed or No Result. Continue to monitor the parameter. When the parameter indicates Inactive, the Catalyst Monitor Test has completed. If the Catalyst Monitor Test Result Bank 1 or Bank 2 parameter indicates No Result Repeat steps 5-8 until the Test Result parameters indicate Passed or Failed If the Catalyst Monitor Test Result Bank 1 or Bank 2 parameter indicates Failed Refer to Circuit /System Testing If the Catalyst Monitor Test Result Bank 1 and Bank 2 parameters indicate Pass
  9. All OK.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine off natural vacuum (EONV) test is the small leak detection diagnostic for the evaporative emission system. This diagnostic tests the evaporative emission (EVAP) system for a small leak when the key is turned OFF and the correct conditions are met. Heat from the exhaust system is transferred into the fuel tank while the vehicle is operating. When the vehicle is turned OFF and the EVAP system is sealed a change in the fuel tank vapor temperature occurs which results in a corresponding pressure change in the fuel tank vapor space. This change is monitored by the engine control module (ECM) using the fuel tank pressure sensor input. With a leak in the system, the amount of pressure change will be less than that of a sealed system.

  1. DTCs P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0222, P0223, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0461, P0462, P0463, P0464, P0496, P0502, P0503, P0608, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138 are not set.
  2. The ignition 1 voltage is between 10-16 volts.
  3. The barometric pressure (BARO) is greater than 74 kPa.
  4. No fuel filling during the EONV test period.
  5. The fuel level is between 15-85 percent.
  6. The start-up engine coolant temperature (ECT) and the start-up intake air temperature (IAT) are between 0-40°C (32-104°F).
  7. The barometric pressure (BARO) is more than 74 kPa.
  8. The engine run time before engine shut-off was greater than 10 minutes.
  9. The drive distance before engine shut-off was more than 5 kilometers (3.1 miles).
  10. The ignition is OFF.
  11. The ambient air temperature at the end of the drive cycle is between 0-32°C (32-93°F).
  12. DTC P0442 runs once per drive cycle during the hot soak period after the ignition is turned OFF and may require up to 45 minutes to complete. The controller will not make more than 2 test attempts per day. The time since the last completed EONV test must be at least 17 hours
  1. The ECM detects a leak in the EVAP system that is greater than a calibrated amount.
  2. The ECM must complete several EONV tests before the diagnostic can turn the MIL on or off.

DTC P0442 is a Type A DTC.

DTC P0442 is a Type A DTC.

  1. The EVAP system can be filled with smoke more quickly and completely by opening the system opposite the end where the smoke is injected. When injecting smoke at the service port remove the fuel fill cap, or temporarily leave the vent open, until smoke is observed then close the system and continue testing. If using a fuel cap adapter at the filler neck, use the J 41413-VLV EVAP service port vent tool at the service port to allow the system to fill faster.
  2. To help locate intermittent leaks using the J 41413-200 evaporative emissions system tester , move all EVAP components while observing smoke with the GE-41413-SPT high intensity white light.
  3. Individual components can be isolated and tested using adapters in the J 41413-300 EVAP cap and plug kit.
  4. A condition may exist where a leak in the EVAP system only exists under a vacuum condition. This type of leak may be detected by using the scan tool Purge/Seal function to create a vacuum in the EVAP system and then observe the FTP parameter for vacuum decay.

DTC Type Reference

Description and Operation

Scan Tool Reference

Control Module References for scan tool information

Special Tools

  1. CH-48096 EVAP Service Access Port Tool
  2. GE-41413-SPT High Intensity White Light
  3. J 41413-200 Evaporative Emissions System Tester (EEST)
  4. J 41413-300 EVAP Cap and Plug Kit
  5. J 41413-VLV EVAP Service Port Vent Tool
IMPORTANTRefer to the J 41413-200 evaporative emissions system tester operation manual for detailed instructions in Evaporative Emission System Diagnosis . Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. Ensure that the underbody temperature of the vehicle and the tester are similar.
  1. Connect the J 41413-200 evaporative emissions system tester to the vehicle at the EVAP service port . For vehicles without a service port, disconnect the purge tube at the quick connector on the EVAP canister side of the purge solenoid valve and install the CH-48096 EVAP service access port tool.
  2. Using a scan tool close the EVAP canister vent valve to seal the EVAP system.
  3. Use the flow meter on the J 41413-200 evaporative emissions system tester , calibrated to 0.51 mm (0.020 in) to determine that there is no leak in the EVAP system. If a leak is detected, use the J 41413-200 evaporative emissions system tester to apply smoke to the EVAP system at the service port or the purge tube until the leak is located using the GE-41413-SPT high intensity white light.
  1. Seal the EVAP system and use the flow meter on the J 41413-200 evaporative emissions system tester , calibrated to 0.51 millimeter (0.020 inch) to determine that there is no leak in the EVAP system.
  2. Clear DTCs.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen / High ResistanceShort to VoltageSignal Performance
Ignition 1 Voltage - Purge SupplyP0443P0443
Battery Positive - Vent SupplyP0449P0449
EVAP Purge Solenoid ControlP0443P0443P0443
EVAP Vent Solenoid ControlP0449P0449P0449

An ignition voltage is supplied directly to the evaporative emission (EVAP) purge solenoid valve. The engine control module (ECM) grounds the EVAP purge solenoid valve control circuit through an internal switch called a driver. The ECM monitors the status of the driver. The EVAP purge solenoid valve is pulse width modulated (PWM). A scan tool will display the amount of ON time as a percentage.

Battery voltage is supplied to the EVAP vent solenoid valve. The ECM grounds the EVAP vent solenoid valve control circuit through an internal switch called a driver. The ECM monitors the status of the driver. A scan tool will display the commanded state of the EVAP vent solenoid valve as ON (Not Venting) or OFF (Venting).

  1. The system voltage is between 11-32 V.
  2. DTCs P0443 and P0449 run continuously when the above conditions are met.

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for a minimum of 0.25 s.

DTCs P0443 and P0449 are Type B DTCs.

DTCs P0443 and P0449 are Type B DTCs.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

P0443

  1. Ignition ON, engine OFF, you should hear a clicking sound when the EVAP purge solenoid valve is commanded to 50 % with a scan tool. The clicking sound should stop when the EVAP purge solenoid valve is commanded to 0 %. The rate at which the valve cycles should increase when the commanded state is increased and decrease when the commanded state is decreased.
  2. Operate the vehicle within the conditions for running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.

P0449

  1. Ignition ON, engine OFF, command the EVAP vent solenoid ON (Not Venting) and OFF (Venting) with a scan tool.
  2. Listen for a click when the valve operates. Verify that both the ON (Not Venting) and the OFF (Venting) states are commanded while watching their parameter status. EVAP Vent Solenoid Valve Control Circuit High Voltage Test Status EVAP Vent Solenoid Valve Control Circuit Low Voltage Test Status EVAP Vent Solenoid Valve Control Circuit Open Test Status Each parameter should display OK or Not Run.
  3. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.
  1. Ignition OFF, disconnect the harness connector at the, Q12 evaporative emission purge solenoid valve for P0443 Q13 evaporative emission vent solenoid valve for P0449
  2. Ignition ON, verify that a test lamp illuminates between the voltage supply circuit, Terminal A and ground for the purge solenoid valve Terminal B and ground for the vent solenoid valve If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the voltage supply circuit fuse is open, test all components connected to the voltage circuit and replace as necessary.
  3. Connect a test lamp between the voltage supply circuit and the control circuit.
  4. With a scan tool command the, EVAP purge solenoid valve to 50 % EVAP vent solenoid valve ON (Not Venting) and OFF (Venting) The test lamp should respond to the command If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
  5. If all circuits test normal, replace the appropriate solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Evaporative Emission Canister Vent Solenoid Valve Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Evaporative Emission Canister Purge Solenoid Valve Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  3. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This DTC tests the evaporative emission (EVAP) system for a restricted or blocked EVAP vent path that would cause excess amounts of vacuum to be developed in the EVAP system. With the purge valve open and the canister vent valve open, if the EVAP system vacuum goes above a calibrated threshold, the test will fail.

FTP Sensor Signal VoltageFuel Tank Pressure
1.5 VAtmospheric Pressure/BARO
Less than 1.5 VPositive Pressure
More than 1.5 VNegative Pressure/Vacuum
  1. DTCs P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0442, P0443, P0449, P0451, P0452, P0453, P0454, P0464, P0496, P0608, P0609, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138 are not set.
  2. The ignition voltage is between 11-18 volts.
  3. The barometric pressure (BARO) is more than 74 kPa.
  4. The fuel level is between 15-85 percent.
  5. The engine coolant temperature (ECT) is less than 35°C (95°F).
  6. The intake air temperature (IAT) is between 4-30°C (39-86°F).
  7. DTC P0446 runs once per cold start when the above conditions are met.
  1. The fuel tank vacuum is greater than -12 inches H2O vacuum for 5 seconds. OR
  2. The FTP is less than -2.5 inches H2O or more than +5 inches for 60 seconds after a cold start.

DTC P0446 is a Type B DTC.

DTC P0446 is a Type B DTC.

  1. An intermittent condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP canister vent solenoid valve inlet, or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill condition.
  2. An EVAP canister filter that is restricted can cause this DTC to set.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  3. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Description and Operation

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON and fuel cap removed, verify that the Fuel Tank Pressure Sensor parameter is between 1.3-1.7 volts. If not within the specified range, go to the fuel tank pressure sensor section in Circuit/System Testing.
  2. Install the fuel cap.
  3. With the engine running, the EVAP canister vent solenoid valve open, use a scan tool to command the EVAP canister purge solenoid valve to 100 percent. The fuel tank vacuum should not increase to more than -15 mmHg (-8 inches H2O). If the fuel tank vacuum is greater than the specified range, go to the restriction section in Circuit/System Testing.
  4. Using the scan tool, decrease the canister purge duty cycle from 100 percent to 0 percent. The vacuum should decrease to near zero. If the fuel tank vacuum does not return to zero or appears to decrease too slowly go to the restriction section in Circuit/System Testing.
  5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Note. Perform the Circuit/System Verification before proceeding with the Circuit/System Testing.

Restriction

  1. With the engine running, the EVAP canister vent solenoid valve open, and the EVAP canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than -15 mmHg (-8 inches H2O). If the fuel tank vacuum is greater than the specified value, isolate the restriction by disconnecting one component at a time while the EVAP canister purge solenoid valve is commanded to 100 percent and the vent valve is open.
  2. Using the scan tool, decrease the canister purge duty cycle from 100 percent to 0 percent. The vacuum should decrease to near zero. If the fuel tank vacuum does not return to zero, or appears to decrease too slowly, inspect the components in the EVAP vent system for a restriction.

Fuel Tank Pressure Sensor

  1. Ignition OFF, disconnect the harness connector at the fuel tank pressure sensor.
  2. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the fuel tank pressure sensor.
  1. «Evaporative Emission Canister Purge Solenoid Valve Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Evaporative Emission Canister Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  3. «Evaporative Emission Canister Vent Solenoid Valve Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  4. «Evaporative Emission Line Replacement - Canister to Tank»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  5. «Evaporative Emission Line Replacement - Engine»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  6. «Evaporative Emission Line Replacement - Engine to Chassis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  7. «Fuel Tank Pressure Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  8. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references)

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

With the engine running, the EVAP canister vent solenoid valve open and the EVAP canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than -15 mmHg (-8 inches H2O).

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
5 V ReferenceP018C, P0192, P0452, P0522, P0532, P0641, P2227, P2228P0451P0446, P0452P018D, P0193, P0453, P0523, P0641, P2227
SignalP0452P0451P0452, P0453P0453P0451, P0454
Low ReferenceP0446, P0451P0446, P0453, P0463P0451
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Ignition ON, Engine OFF Parameter Normal Range: 1.3-1.7 V
5 V Reference0 V0 V4.2-5 V
Sensor Signal0 V0 V5 V
Sensor Low Reference4.5 V

FTP Sensor Voltage

The Fuel Tank Pressure (FTP) sensor measures air pressure or vacuum in the evaporative emission (EVAP) system. The engine control module (ECM) supplies a 5 V reference and a low reference circuit to the FTP sensor. The FTP sensor signal voltage varies depending on EVAP system pressure or vacuum. The controller also uses this FTP signal to determine atmospheric pressure for use in the engine-off small leak test, DTC P0442. Before using this signal as an atmospheric reference it must first be re-zeroed.

P0451

  1. DTC P0451 runs only when the engine-off natural vacuum small leak test, P0442, executes.
  2. The number of times this test runs can range from 0-2 per engine-off period. The length of the test can be up to 10 min.

P0452 and P0453

DTC P0452 and P0453 run continuously when the ignition is ON.

P0454

  1. DTC P0454 runs only when the engine-off natural vacuum small leak test, P0442, executes.
  2. This test can run once per engine-off period. The length of the test can be up to 10 min.
  3. A refueling event is not detected. A refueling event is confirmed if the fuel level has a persistent change of 10% for 30 s during a 10 min refueling rationality test.

P0451

This DTC will set if the controller is unable to re-zero the FTP Sensor voltage within a calibrated range during the engine-off small leak test, P0442.

P0452

The FTP Sensor voltage is less than 0.15 V for more than 10 s.

P0453

The FTP Sensor voltage is more than 4.9 V for more than 10 s.

P0454

If, during the engine-off natural vacuum small leak test, P0442, the ECM detects an abrupt FTP signal change, other than a refueling event, this DTC will set. An abrupt change is defined as a change of greater than 0.45 in H2O in the span of 1 s but less than 1 in H2O in 12.5 ms. This test must fail twice to set this DTC.

  1. DTCs P0451 and P0454 are Type A DTCs.
  2. DTCs P0452 and P0453 are Type B DTCs.
  1. DTCs P0451 and P0454 are Type A DTCs.
  2. DTCs P0452 and P0453 are Type B DTCs.

P0451 and P0454

  1. A restriction in the EVAP canister or vent lines could prevent fuel vapor pressure from bleeding off fast enough. If the vent system cannot bleed off pressure fast enough, the re-zero procedure may not complete successfully, which could cause this code to set.
  2. Ensure that the reference port on the FTP Sensor is unobstructed.
  3. An FTP Sensor that is skewed or does not have a linear transition from low to high may cause this code to set. Scan tool output controls, snapshot, and plot functions can help detect erratic sensor response. To test the sensor signal under vacuum conditions, use the Quick Snapshot and the Purge/Seal functions to capture data while commanding purge to 20%, then plot the data to look for erratic sensor operation. A similar test can be done for the pressure side of the sensor operation by applying pressure with the GE 41413-A while taking a snapshot.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

GE 41413-A Evaporative Emission System Tester (EEST)

For equivalent regional tools, refer to Special Tools (Diagnostic Tools)

  1. Remove the fuel cap.
  2. Ignition ON, engine OFF.
  3. Verify the scan tool Fuel Tank Pressure Sensor parameter is between 1.3 and 1.7 V. If not between 1.3-1.7 V Refer to Circuit/System Testing If between 1.3-1.7 V
  4. All OK.
  1. Ignition OFF, all vehicle systems OFF, this may take up to 2 min, for all vehicle systems to power down. Disconnect the harness connector at the B150 Fuel Tank Pressure Sensor.
  2. Test for less than 5 ohms of resistance between the low reference circuit terminal 2 and ground. If 5 ohms or greater Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If less than 5 ohms
  3. Ignition ON.
  4. Test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground. If less than 4.8 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the 5 V reference circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the 5 V reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 5.2 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the 5 V reference circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If between 4.8-5.2 V
  5. 5. Verify the scan tool Fuel Tank Pressure Sensor parameter is less than 0.2 V. If 0.2 V or greater Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON Test for less than 1 V between the signal circuit terminal 1 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If less than 0.2 V
  6. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the 5 V reference circuit terminal 3.
  7. Verify the scan tool Fuel Tank Pressure Sensor parameter is greater than 4.7 V. If 4.7 V or less Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit terminal 1 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 4.7 V
  8. Test or replace the B150 Fuel Tank Pressure Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Fuel Tank Pressure Sensor Replacement (Signle)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-repair-instructions) , «Fuel Tank Pressure Sensor Replacement (Dual Tank)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The ECM tests the Evaporative Emission (EVAP) System for a large leak or restrictions to the purge path in the EVAP system. When the enabling criteria has been met the ECM commands the EVAP canister vent solenoid valve ON and the EVAP canister purge solenoid valve ON, allowing vacuum into the EVAP system. The ECM monitors the fuel tank pressure (FTP) sensor voltage to verify that the system is able to reach a predetermined level of vacuum within a set amount of time.

  1. Before the ECM can report DTC P0455 failed, DTC P0496 must run and pass.
  2. DTCs P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0442, P0443, P0449, P0451, P0452, P0453, P0454, P0464, P0496, P0608, P0609, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138 are not set.
  3. The ignition voltage is between 11-18 volts.
  4. The barometric pressure (BARO) is more than 74 kPa.
  5. The fuel level is between 15-85 percent.
  6. The engine coolant temperature (ECT) is less than 35°C (95°F).
  7. The intake air temperature (IAT) is between 4-30°C (39-86°F).
  8. DTC P0455 runs once per cold start when the above conditions are met.

The EVAP system is not able to achieve or maintain a calibrated level of vacuum within a set amount of time.

DTC P0455 is a Type B DTC.

DTC P0455 is a Type B DTC.

  1. Inspect for a loose, missing, damaged, or incorrect fuel fill cap.
  2. Inspect for a damaged fuel filler neck seal surface.
  3. A blockage or restriction in the EVAP purge solenoid valve, purge pipe, EVAP canister, or vapor pipe, can cause this DTC to set.
  4. The EVAP system can be filled with smoke more quickly and completely by opening the system opposite the end where the smoke is injected. For example, when injecting smoke at the service port remove the fuel fill cap, or temporarily leave the vent open, until smoke is observed, then close the system and continue testing. If using a fuel cap adapter at the filler neck, use the J 41413-VLV EVAP service port vent tool at the service port to allow the system to fill faster.
  5. To help locate intermittent leaks using the J 41413-200 evaporative emissions system tester , move all EVAP components while observing smoke with the GE-41413-SPT high intensity white light .
  6. Individual components can be isolated and tested using adapters in the J 41413-300 EVAP cap and plug kit .
  7. A condition may exist where a leak in the EVAP system only exists under a vacuum condition. This type of leak may be detected by using the scan tool Purge/Seal function to create a vacuum in the EVAP system and then observe the FTP parameter for vacuum decay.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

  1. CH-48096 EVAP Service Access Port Tool
  2. GE-41413-SPT High Intensity White Light
  3. GE-41415-50 Fuel Tank Cap Adapter
  4. J-41413-311 Brass Cone Adapter
  5. J 41413-200 Evaporative Emissions System Tester (EEST)
  6. J 41413-300 EVAP Cap and Plug Kit
  7. J 41413-VLV EVAP Service Port Vent Tool
IMPORTANTLarger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. Refer to the J 41413-200 evaporative emissions system tester operation manual for detailed instructions in Evaporative Emission System Diagnosis .
  1. Connect the J 41413-200 evaporative emissions system tester to the vehicle EVAP service port. For vehicles without a service port, disconnect the purge tube at the quick connector on the EVAP canister side of the purge solenoid valve and install the CH-48096 EVAP service access port tool .
  2. Use a scan tool to seal the EVAP system.
  3. Use the flow meter on the J 41413-200 evaporative emissions system tester , calibrated to 0.51 mm (0.020 in) to determine that there is no leak in the EVAP system. If a leak is detected, use the J 41413-200 evaporative emissions system tester to apply smoke to the EVAP system at the service port or the purge tube until the leak is located using the GE-41413-SPT high intensity white light.
  4. To test for a restriction in the purge path, connect the J 41413-200 evaporative emissions system tester nitrogen/smoke hose to the J-41413-311 brass cone adapter . Disconnect the hose at the fuel cap end of the GE-41415-50 fuel tank cap adapter . Connect the J-41413-311 brass cone adapter to the disconnected hose on the GE-41415-50 fuel tank cap adapter . Install the GE-41415-50 fuel tank cap adapter filler neck end only to the vehicle.
  5. Allow the engine to idle.
  6. Use the Purge/Seal function to seal the system with a scan tool.
  7. Command the EVAP canister purge solenoid valve to 30 percent.
  8. The vacuum/pressure gauge on the J 41413-200 evaporative emissions system tester and the FTP parameter on the scan tool should both show vacuum. If the vacuum/pressure gauge shows vacuum, but the FTP parameter does not show vacuum, replace the FTP sensor. If neither the FTP parameter nor the vacuum/pressure gauge shows vacuum, repair the restriction in the purge path.
  9. Verify that the vacuum increases to the abort limit on the scan tool or more than 3.2 volts, and the values are similar between the scan tool and the vacuum/pressure gauge on the J 41413-200 evaporative emissions system tester . If the values are not similar, or the voltage did not reach 3.2 volts, replace the FTP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This DTC tests for undesired intake manifold vacuum flow to the evaporative emission (EVAP) system. The engine control module (ECM) seals the EVAP system by commanding the EVAP canister purge solenoid valve OFF and the EVAP canister vent solenoid valve ON. The ECM monitors the fuel tank pressure (FTP) sensor to determine if a vacuum is being drawn on the EVAP system. If vacuum in the EVAP system is more than a predetermined value within a predetermined time, this DTC sets.

The following table illustrates the relationship between the ON and OFF states, and the Open or Closed states of the EVAP canister purge and vent solenoid valves.

Control Module CommandEVAP Canister Purge Solenoid ValveEVAP Canister Vent Solenoid Valve
ONOpenClosed
OFFClosedOpen
  1. DTCs P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0464, P0608, P0609, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138 are not set.
  2. The ignition voltage is between 11-18 volts.
  3. The barometric pressure (BARO) is more than 74 kPa.
  4. The fuel level is between 15-85 percent.
  5. The engine coolant temperature (ECT) is less than 35°C (95°F).
  6. The intake air temperature (IAT) is between 4-30°C (39-86°F).
  7. DTC P0496 runs once per cold start when the above conditions are met.

The ECM detects more than 10 inch H2O vacuum for 5 seconds during a non-purge condition.

DTC P0496 is a Type B DTC.

DTC P0496 is a Type B DTC.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  3. «Troubleshooting with a Test Lamp»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__troubleshooting-with-a-test-lamp)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Description and Operation

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, engine OFF, seal the EVAP system using the Purge/Seal function with a scan tool.
  2. Start the engine.
  3. Observe the FTP sensor with a scan tool. The Fuel Tank Pressure Sensor parameter should be less than 1.7 volts after 90 seconds. If the Fuel Tank Pressure Sensor parameter is greater than the specified range, go to Circuit/System Testing.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Start the engine.
  2. Seal the EVAP system using the Purge/Seal function with a scan tool.
  3. Observe the FTP sensor with a scan tool. The Fuel Tank Pressure Sensor parameter should be less than 1.7 volts after 90 seconds. If the Fuel Tank Pressure Sensor parameter is greater than the specified range, replace the EVAP canister purge solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The throttle actuator control (TAC) motor is controlled by the engine control module (ECM). The DC motor located in the throttle body drives the throttle blade. In order to decrease idle speed, along with spark and fuel delivery changes the ECM commands the throttle closed reducing air flow into the engine and the idle speed decreases. In order to increase idle speed, the ECM commands the throttle plate open allowing more air to pass the throttle plate.

  1. DTCs P0068, P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0171, P0172, P0174, P0175, P0201-P0208, P0220, P0222, P0223, P0300-P0308, P0351-P0358, P0461- P0463, P0496, P0502, P0503, P0606, P0722, P0723, P0806-P0808, P1516, P2066-P2068, P2101, P2135 are not set.
  2. The engine is operating for at least 60 s.
  3. The engine is idling for greater than 10 s.
  4. The barometric pressure (BARO) is greater than 70 kPa (11 psi).
  5. The engine coolant temperature (ECT) is greater than 60°C (140°F).
  6. The intake air temperature (IAT) is warmer than -20°C (-4°F).
  7. The vehicle speed is less than 3 km/h (2 mph).
  8. The commanded engine speed is steady within 25 RPM.
  9. The transmission is not changing gears.
  10. The torque converter clutch (TCC) is not changing states.
  11. The manual transmission clutch pedal position is between 16-88 percent - If equipped.
  12. The manual transmission clutch is not depressed - If equipped.
  13. The power take-off (PTO) is not active - If equipped.
  14. The transfer case is not in 4WD Low - If equipped.
  15. A scan tool output control is not active.
  16. The system voltage is between 11-32 V.
  17. DTC P0506 and P0507 run continuously when the above conditions are met for greater than 10 s.

P0506

The actual idle speed is approximately 91 RPM lower than the desired idle speed.

P0507

The actual idle speed is approximately 182 RPM greater than the desired idle speed.

DTCs P0506 and P0507 are Type B DTCs.

DTCs P0506 and P0507 are Type B DTCs.

  1. A stalling condition can cause DTC P0506 to set.
  2. An intermittent vehicle speed sensor (VSS) signal can cause DTC P0507 to set.
  3. An intermittent clutch pedal position sensor signal, if equipped, can cause DTC P0506 to set.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify no other DTCs set. If any other DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If no other DTC is set
  3. Verify the scan tool TB Idle Airflow Compensation parameter is less than 90 %. 90 % or greater Refer to «Throttle Body Cleaning»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-repair-instructions__throttle-body-cleaning) . If less than 90 %
  4. Engine Idling at the normal operating temperature.
  5. Verify the actual Engine Speed is not 100 RPM less than the Desired Idle Speed. If 100 RPM less than the Desired Idle Speed Refer to Circuit/System Testing. If 100 RPM greater than the Desired Idle Speed
  6. Verify the actual Engine Speed is not 200 RPM greater than the Desired Idle Speed. If 200 RPM greater than the Desired Idle Speed Refer to Circuit/System Testing. If 200 RPM less than the Desired Idle Speed
  7. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  8. Verify a DTC does not set. If any DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If no DTCs set
  9. All OK

P0506

  1. Verify the conditions listed below do not exist. Restricted exhaust Mechanical conditions that limits engine speed Parasitic load on the engine-For example, a transmission condition, a belt driven accessory condition. If a condition is found Repair as necessary. If a condition is not found
  2. All OK.

P0507

  1. Verify the conditions listed below do not exist. Vacuum leaks A throttle valve that does not close correctly Verify the correct operation of the crankcase ventilation system. Inspect for the conditions listed below: Improper routing of the positive crankcase ventilation (PCV) system Vacuum leaks in the PCV system-Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-48l-l20-53l-lmf-or-60l-l96-lc8-diagnostic-information-and-procedures__crankcase-ventilation-system-inspectiondiagnosis) . If a condition is found Repair as necessary. If a condition is not found
  2. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
SignalP057CP057CP057DP057B
5 V ReferenceP057C P0651P057CP0651
Low ReferenceP057DP057D
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Ignition ON. Brake Pedal Position Sensor Parameter Normal Range: 0.25-4.75 V
5 V Reference0 V0 V
Signal0 V0 V5 V
Low Reference5 V

Brake Pedal Position Sensor

The brake pedal position (BPP) sensor is part of the engine brake pedal override feature. The engine control module (ECM) continuously monitors the vehicle speed and the position of the brake pedal. These two main inputs, along with other ECM inputs are used to determine if the vehicle is decelerating at the proper speed and rate with the brake pedal applied. When the engine brake pedal override system is active, the ECM reduces engine torque to assist in reducing vehicle speed.

The BPP sensor is a six wire sensor, and is part of a dual brake position sensor. One BPP Sensor is used for the stop lamps and the other BPP Sensor is used for the engine brake pedal override feature. The BPP Sensor for engine brake pedal override communicates with the ECM. The ECM supplies a 5 V reference circuit, low reference circuit, and signal circuit to the BPP sensor. The BPP sensor sends a voltage signal to the ECM on the signal circuit. The voltage on the signal circuit will vary from a voltage greater than 0.25 V when the brake pedal is released to a voltage less than 4.75 V when the brake pedal is fully applied.

For information on the Stop Lamps side of the BPP Sensor, refer to Exterior Lighting Systems Description and Operation .

  1. Ignition voltage is greater than 10 V.
  2. DTC runs continuously when above condition is met.

P057B

ECM detects the BPP sensor signal is stuck in a range.

P057C

ECM detects the BPP sensor voltage is less than 0.25 V for 1 s.

P057D

ECM detects the BPP sensor voltage is greater than 4.75 V for 1 s.

  1. P057B, P057C, and P057D are Type A DTCs.
  2. Engine torque is reduced to 50% of available engine torque during brake torque management.
  3. Brake torque management is active at 25 kPa (3.7 PSI) of brake apply pressure.

P057B, P057C, and P057D are Type A DTCs

Schematic Reference

  1. «Engine Controls Schematics»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-wiring-schematic-diagrams)
  2. «Exterior Lights Schematics»(/chevrolet/express-g3500/2013-2013/remont/exterior-lights/#lighting-system)

Connector End View Reference

  1. «COMPONENT CONNECTOR END VIEWS - INDEX»(/chevrolet/express-g3500/2013-2013/remont/body-electrical/#wiring-systems-and-power-management-component-connector-end-views-index)
  2. «Inline Harness Connector End Views»(/chevrolet/express-g3500/2013-2013/remont/body-electrical/#wiring-systems-and-power-management-inline-harness-connector-end-views-x318-to-x902)

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Verify DTC P0641, P0651, P0697, or P06A3 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If none of the DTCs are set
  2. Ignition ON, transmission in Park, and service brake pedal released.
  3. Verify the scan tool Brake Pedal Position Sensor parameter in the ECM displays greater than 0.25 V. If 0.25 V or less Refer to Circuit/System Testing. If greater than 0.25 V
  4. Verify the scan tool Brake Pedal Position Sensor parameter voltage changes as the brake pedal is applied and displays less than 4.75 V when the brake pedal is fully applied. If the voltage does not change, or is greater than 4.74 V Refer to Circuit/System Testing. If the voltage changes and less than 4.75 V
  5. Verify the scan tool Brake Pedal Position Sensor Learned Release Position parameter is within 0.1 V of the Brake Pedal Position Sensor parameter when the brake pedal is fully released. If difference is greater than 0.1 V Perform the «Brake Pedal Position Sensor Learn»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__brake-pedal-position-sensor-learn) . If difference is 0.1 V or less
  6. Verify the Brake Pedal Position Sensor parameter transitions smoothly without any spikes or dropouts when slowly applying and releasing the brake pedal. If parameter does not transition smoothly or has spikes or dropouts Refer to Circuit/System Testing. If parameter transitions smoothly and there are no spikes or dropouts
  7. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  8. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  9. All OK.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B22 Brake Pedal Position Sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 10 ohms between the low reference circuit terminal 6 and ground. If 10 ohms or greater Disconnect the harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If less than 10 ohms
  3. Ignition ON.
  4. Test for 4.8-5.2 V between the 5 V reference circuit terminal 5 and ground. If less than 4.8 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the 5 V reference circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance. Test for less than 2 ohms in the 5 V reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 5.2 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the 5 V reference circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If between 4.8-5.2 V
  5. Verify the scan tool Brake Pedal Position Sensor parameter is less than 0.25 V. If 0.25 V or greater Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON. Test for less than 0.25 V between the signal circuit terminal 4 and ground. If 0.25 V or greater, repair the short to voltage on the circuit. If less than 0.25 V, replace the K20 Engine Control Module. If less than 0.25 V
  6. Install a 3 A fused jumper wire between the signal circuit terminal 4 and the 5 V reference circuit terminal 5.
  7. Verify the scan tool Brake Pedal Position Sensor parameter is greater than 4.8 V. If 4.8 V or less Ignition OFF, remove the jumper wire, and disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit terminal 4 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance. Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 4.8 V
  8. Replace the B22 Brake Pedal Position Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Brake Pedal Position Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/exterior-lights/#lighting-system__brake-pedal-position-sensor-replacement)
  2. Perform the «Brake Pedal Position Sensor Learn»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__brake-pedal-position-sensor-learn) following the replacement of the ECM or BPP sensor, or any repair that effects the BPP sensor alignment.
  3. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Engine Control Module replacement, programming and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each of the diagnostic category.

This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM) and the throttle actuator control (TAC) system. This diagnostic also addresses if the ECM is not programmed.

The ECM monitors its ability to read and write to the memory. It also monitors a timing function. The ECM and the TAC processors are used to monitor the TAC system data. Both processors monitor the other processors data to verify that the indicated APP calculation is correct. The ECM performs an intrusive test in order to confirm that the APP signals are not shorted together. The ECM accomplishes this by pulling the APP sensor 2 low momentarily and looking for sensor 1 to also be pulled low.

P0601, P0604

  1. The ignition switch is in Run or Crank.
  2. These DTCs run continuously when the above condition is met.

P0602, P0603, P062F

  1. The ignition switch is in Run or Crank.
  2. These DTCs run once per ignition cycle.

P0606, P0607, P060D

  1. The ignition voltage is more than 6.0 V.
  2. Reduced Engine Power is not active.
  3. These DTCs run continuously when the above conditions are met.

P2610

  1. The intake air temperature is between -40 to +125°C (-40 to +257°F).
  2. DTC P2610 runs once per ignition cycle.

The ECM detects an internal failure or incomplete programming for more than 10 s.

Actions Taken When the DTC Sets

  1. DTCs P0601, P0602, P0603, P0604, P0606, P060D, and P062F are Type A DTCs.
  2. DTC P0607 is a Type C DTC.
  3. DTC P2610 is a Type B DTC.
  1. DTCs P0601, P0602, P0603, P0604, P0606, P060D, and P062F are Type A DTCs.
  2. DTC P0607 is a Type C DTC.
  3. DTC P2610 is a Type B DTC.

Low voltage or a momentary loss of power or ground to the ECM may cause a DTC to set.

  1. Verify that the battery cables are clean and tight, and the battery is fully charged. Refer to «Battery Inspection/Test»(/chevrolet/express-g3500/2013-2013/remont/charging-system/#battery-charging-system-and-starting-system) .
  2. Verify the ECM ground circuits do not have an open or high resistance.
  3. Verify the ECM power circuits do not have an open, short to ground, or high resistance.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Observe the DTC information with a scan tool. DTC P0601, P0602, P0603, P0604, P0606, P0607, P060D, P062F, or P2610 should not set.
  2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition ON, clear the DTC information with a scan tool. Observe the scan tool DTC information. If DTC P0602 is set, reprogram the K20 ECM. Refer to «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for K20 ECM replacement, setup, and programming. If DTC P0602 resets, replace the K20 ECM.
  2. Observe the DTC information with a scan tool. Verify that DTC P0601, P0603, P0604, P0606, P0607, P060D, P062F, or P2610 does not set. If a DTC failed this ignition, replace the K20 ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, programming and setup

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The engine control module (ECM) has 2 internal 5V reference circuits. Each internal reference circuit provides external 5V reference circuits for more than one sensor. A short to ground or short to voltage on one external 5V reference circuit can affect all the components connected to the same internal 5V reference circuit.

  1. Reduced engine power is not active.
  2. The ignition voltage is more than 6 V.
  3. DTCs P0641 and P0651 run continuously when the above conditions are met.

The ECM detects a short to ground or voltage on the 5V reference 1 or 2 circuit for greater than 0.5 s.

DTCs P0641 and P0651 are Type A DTCs.

DTCs P0641 and P0651 are Type A DTCs.

P0641

The 5V reference 1 circuit provides 5 V to the following sensors

  1. Manifold absolute pressure sensor
  2. Fuel tank pressure sensor
  3. Air conditioning (A/C) refrigerant pressure sensor
  4. Accelerator pedal position sensor 2
  5. Engine oil pressure sensor
  6. Camshaft position sensor

The 5V reference 2 circuit provides 5 V to the following sensors

  1. Accelerator pedal position sensor 1
  2. Throttle position sensor 1 and 2
  3. Crankshaft position sensor
  4. Brake pedal position sensor

Disconnecting one component at a time from the affected 5V reference circuit while observing the scan tool 5V Reference Circuit Status parameter may help locate the fault. The scan tool parameter will change from Malfunction to OK when the source of the fault is disconnected. If all 5V reference components have been disconnected and a fault is still indicated, the fault may exist in the wiring harness.

Schematic Reference

Connector End View Reference

Component View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the scan tool 5V reference 1 and 2 parameters. Each parameter should display OK.
  2. Ignition ON, observe the DTC information with a scan tool. DTC P0641 and P0651 should not set.
  3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Note. Additional DTCs may set when disconnecting components.

  1. Ignition OFF, disconnect the harness connector of all the sensors connected to the 5V reference circuit for the applicable DTC. Refer to Diagnostic Aids.
  2. Ignition ON, test for 4.8-5.2 V between one of the 5V reference circuits and ground. If less than the specified range, test for a short to ground on the 5V reference circuit for each affected component. If all circuits test normal, replace the K20 Engine Control Module. If greater than the specified range, test for a short to voltage on the 5V reference circuit for each affected component. If all circuits test normal, replace the K20 Engine Control Module.
  3. Connect each component associated with the 5V reference circuit, one at a time, while monitoring the appropriate scan tool 5V Reference 1 or 2 voltage parameter. Verify the voltage remains between 4.8-5.2 V. If not within the specified range when a component is connected, test the signal circuit for a short to voltage. If the circuit tests normal, replace the component.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Accelerator Pedal Position Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (L96)»(/chevrolet/express-g3500/2013-2013/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning)
  3. «Brake Pedal Position Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/exterior-lights/#lighting-system__brake-pedal-position-sensor-replacement)
  4. «Camshaft Position Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  5. «Crankshaft Position Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  6. «Engine Oil Pressure Sensor and/or Switch Replacement»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3__engine-oil-pressure-sensor-andor-switch)
  7. «Fuel Tank Pressure Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  8. «Manifold Absolute Pressure Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  9. «Throttle Body Assembly Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  10. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Ignition VoltageP0650P0650
MIL ControlP0650*P0650P0650
* The MIL remains ON

The malfunction indicator lamp (MIL) illuminates to inform the driver that an emission system failure has occurred and the engine control system requires service. Ignition voltage is supplied directly to the MIL. The engine control module (ECM) turns the MIL ON by grounding the MIL control circuit when the emission system fault occurs. Under normal operating conditions, the MIL should be ON only when the ignition is ON and the engine is OFF.

  1. The ignition is in the Run or Crank position.
  2. The ignition voltage is between 9-18 volts.
  3. DTC P0650 runs continuously when the ignition is ON.

The ECM detects that the commanded state of the MIL driver and the actual state of the control circuit do not match for more than 5 seconds.

DTC P0650 is a Type B DTC.

DTC P0650 is a Type B DTC.

If the condition is intermittent, move the related harnesses and connectors while monitoring the scan tool MIL control circuit status parameters. Perform this test with the ignition ON and the engine OFF, and with the engine running. The MIL control circuit status parameters will change from OK or Not Run to Malfunction if there is a condition with the circuit or a connection.

Schematic Reference

  1. «Instrument Cluster Schematics»(/chevrolet/express-g3500/2013-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)
  2. «Engine Controls Schematics»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-wiring-schematic-diagrams)

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, command the malfunction indicator lamp ON and OFF with a scan tool.
  2. Verify that the malfunction indicator lamp turns ON and OFF as commanded. If the malfunction indicator lamp does not turn ON and OFF as commanded Refer to Circuit/System Testing. If the malfunction indicator lamp turns ON and OFF as commanded
  3. Ignition ON, command the malfunction indicator lamp ON and OFF with a scan tool.
  4. Verify that the control circuit status parameters listed below display OK or Not Run The MIL Control Circuit Low Voltage Test Status The MIL Control Circuit Open Test Status The MIL Control Circuit High Voltage Test Status If Malfunction is displayed Refer to Circuit/System Testing. If OK or Not Run is displayed
  5. Engine running, command the malfunction indicator lamp ON and OFF with a scan tool.
  6. Verify that the control circuit status parameters listed below display OK or Not Run The MIL Control Circuit Low Voltage Test Status The MIL Control Circuit Open Test Status The MIL Control Circuit High Voltage Test Status If Malfunction is displayed Refer to Circuit/System Testing. If OK or Not Run is displayed
  7. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. If any DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If a DTC does not set
  8. All OK.
  1. Ignition OFF.
  2. Disconnect the X1 harness connector at the K20 Engine Control Module.
  3. Ignition ON, verify the malfunction indicator lamp does not illuminate. If the malfunction indicator lamp illuminates Test for infinite resistance between the malfunction indicator lamp control circuit terminal X1 27 and ground. If less than infinite resistance, repair the short to ground in the circuit. If resistance is infinite, replace the P16 instrument cluster. If the malfunction indicator lamp does not illuminate
  4. Connect a 3 A fused jumper wire between the malfunction indicator lamp control circuit terminal X1 27 and ground.
  5. Verify the malfunction indicator lamp illuminates. If the malfunction indicator lamp does not illuminate Test the malfunction indicator lamp control circuit terminal X1 27 for a short to voltage or an open/high resistance. If the malfunction indicator lamp control circuit terminal X1 27 is shorted to voltage or has an open/high resistance, repair as necessary. If the malfunction indicator lamp control circuit terminal X1 27 tests normal Test the instrument cluster ignition voltage circuit for a short to ground or an open/high resistance. If the instrument cluster ignition voltage circuit is shorted to ground or has an open/high resistance, repair as necessary. If the instrument cluster ignition voltage circuit tests normal, replace the P16 instrument panel cluster/bulb. If the malfunction indicator lamp illuminates
  6. Replace the K20 Engine Control Module.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup.
  2. «Instrument Cluster Replacement»(/chevrolet/express-g3500/2013-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to Voltage
Relay Coil Supply VoltageP0685P0685
Relay Control CircuitP0685P0685, P1682P0685, P0690, P1682
Relay Feedback CircuitP0690

Engine Controls Ignition Relay

CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Component commanded OFF Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component OFF - OK for Open/Low Voltage test and Not Run for High Voltage test Component ON - Not Run for Open/Low Voltage test and OK for High Voltage test
B+Malfunction
ControlMalfunctionMalfunctionNot Run

Engine Controls Ignition Relay Control Circuit Low Voltage, Open, and High Voltage Test Status-Component Commanded OFF

CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Component commanded ON Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component OFF - OK for Open/Low Voltage test and Not Run for High Voltage test Component ON - Not Run for Open/Low Voltage test and OK for High Voltage test
B+Not Run
ControlNot RunNot RunMalfunction

Engine Controls Ignition Relay Control Circuit Low Voltage, Open, and High Voltage Test Status-Component Commanded ON

There are 2 ignition voltage circuits supplied to the engine control module (ECM). One is supplied by the engine controls ignition relay and the other is supplied by the run/crank relay. The ECM monitors and compares the ignition voltage supplied by the 2 relays.

P0685

  1. The ignition is ON.
  2. Ignition 1 signal voltage is between 11-32 V.
  3. The DTC runs continuously when the above conditions are met.

P0690

  1. The engine controls ignition relay is commanded on.
  2. P0685 is not set.
  3. The DTC runs continuously when the above conditions are met.

P1682

  1. The engine controls ignition relay is commanded on.
  2. The ignition voltage is greater than 5.5 V.
  3. The DTC runs continuously when the above conditions are met.

P0685

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 2 s.

P0690

  1. The ECM detects the engine controls ignition relay feedback circuit is greater than 3 V when the relay is commanded OFF.
  2. The ECM detects the engine controls ignition relay feedback circuit is greater than 18 V when the relay is commanded ON.
  3. The condition is present for greater than 4 s.

P1682

The ECM detects that the voltage level difference is greater than 3 V between the 2 ignition voltage circuits for greater than 1 s.

  1. DTCs P0685 and P0690 are Type B DTCs.
  2. DTC P1682 is a Type A DTC.
  1. DTCs P0685 and P0690 are Type B DTCs.
  2. DTC P1682 is a Type A DTC.

The engine controls ignition relay may also be labeled the powertrain relay, the engine control module relay, or the main relay. The run/crank relay may also be labeled the ignition run relay, the ignition main relay, the ignition 1 relay, or the ignition relay.

Schematic Reference

  1. «Engine Controls Schematics»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-wiring-schematic-diagrams)
  2. «Power Distribution Schematics»(/chevrolet/express-g3500/2013-2013/remont/body-electrical/#wiring-systems-and-power-management-wiring-schematics-and-wiring-harness-routing-diagrams)

Connector End View Reference

Component View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Electrical Center Identification Views»(/chevrolet/express-g3500/2013-2013/remont/electrical-component-locations/#wiring-systems-and-power-management-component-locator-electrical-center-identification-views)
  4. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  5. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, command the Engine Controls Ignition Relay ON and OFF with a scan tool while observing the parameters listed below: Engine Controls Ignition Relay Control Circuit Low Voltage Test Status Engine Controls Ignition Relay Control Circuit Open Test Status Engine Controls Ignition Relay Control Circuit High Voltage Test Status Each parameter should display OK or Not Run in each commanded state.
  2. Ignition ON, view the DTC information with a scan tool. DTC P0685, P0690, or P1682 should not set.
  3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Note. You must perform the Circuit/System Verification before proceeding with Circuit/System Testing unless sent here from Engine Cranks But Does Not Run.

  1. Ignition OFF, disconnect the KR75 Engine Controls Ignition Relay.
  2. Verify a test lamp illuminates between ground and the relay circuit terminals listed below: Terminal 85 Terminal 30 If the test lamp does not illuminate, test the relay battery voltage circuit for an open/high resistance.
  3. Ignition ON, verify that a test lamp does not illuminate between the ignition voltage circuit terminal 87 and ground. If the test lamp illuminates, test the ignition voltage circuit for a short to voltage.
  4. Connect a 20 A fused jumper wire between the relay switch B+ circuit terminal 30 and the relay switch ignition voltage circuit terminal 87.
  5. Ignition ON, verify the Engine Controls Ignition Relay Feedback Signal parameter displays B+. If not the specified value, test the ignition voltage circuit between the KR75 Engine Controls Ignition Relay and the K20 Engine Control Module for a short to ground or for an open/high resistance. If the circuit/connections test normal, replace the K20 Engine Control Module.
  6. Ignition OFF, connect a DMM set to the diode setting between control circuit terminal 86 and ground. Verify the DMM displays OL. If not the specified value, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.
  7. Ignition ON, verify the DMM displays less than 1 V. If not the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
  8. If all circuits test normal, replace the KR75 Engine Controls Ignition Relay.
  1. Test for one of the following resistance specifications between terminals 85 and 86 of the KR75 Engine Controls Ignition Relay: 70-110 ohms 200-250 ohms If not within the specified range, replace the relay.
  2. Test for infinite resistance between the following terminals of the relay: 30 and 86 30 and 87 30 and 85 85 and 87 If not the specified value, replace the relay.
  3. Install a 20 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87. If greater than the specified range, replace the relay.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Relay Replacement (Within an Electrical Center)»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) , «Relay Replacement (Attached to Wire Harness)»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each of the diagnostic category.

Diagnostic trouble code (DTC) P0700 is an informational DTC that indicates that an emission related transmission DTC has set in the transmission control module (TCM). The engine control module (ECM) turns ON the malfunction indicator lamp (MIL) when the TCM sends a message over the serial data circuit requesting MIL illumination. The DTC information for the ECM will only display DTC P0700, and the ECM Freeze Frame/Failure Records data will display the engine operating conditions that were present when the transmission DTC was set. The TCM Freeze Frame/Failure records data is available from the DTC that was set in the TCM.

  1. The ignition is ON or the engine is operating.
  2. DTC P0700 runs continuously.

The ECM receives a serial data message from the TCM requesting the ECM to turn ON the MIL.

DTC P0700 is a Type A DTC.

DTC P0700 is a Type A DTC.

Communication codes, U-codes, as well as powertrain codes, P-codes, set in the TCM can cause the TCM to request DTC P0700 to be set in the ECM.

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Verify there are no engine control or communication DTCs set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If a DTC is not set
  2. Verify there are no transmission control module DTCs set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If a DTC is not set
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  4. Verify the DTC does not set. If the DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If the DTC does not set
  5. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The engine control module (ECM) detects engine misfire by detecting variations in crankshaft deceleration between firing strokes. For accurate detection of engine misfire, the ECM must distinguish between crankshaft deceleration caused by actual misfire and deceleration caused by rough road conditions. The antilock brake system (ABS) can detect if the vehicle is on a rough road based on wheel acceleration/deceleration data supplied by the wheel speed sensors. If the ABS detects rough road above predetermined threshold, this information is sent to the ECM. The ECM uses the rough road information when calculating engine misfire. If the ABS is malfunctioning and cannot detect rough roads, the misfire diagnostic will continue to run; however, if an engine misfire DTC sets, this DTC also sets indicating that rough road data was not available, or there was no communication with the brake control module during the misfire calculation due to an ABS malfunction.

  1. The vehicle speed is greater than 8 km/h (5 mph).
  2. The engine speed is less than 7,000 RPM.
  3. The engine load is less than 60 percent.
  4. Engine misfire is detected and DTC P0300 sets with the MIL illuminated.
  5. DTCs P1380 and P1381 run continuously when the above conditions are met.

P1380

  1. The ABS controller sends a message to the ECM indicating that a failure has occurred in the ABS module.
  2. Engine misfire is detected and DTC P0300 set.

P1381

  1. An ABS malfunction exists for more than 10 seconds, preventing the ECM from receiving rough road detection data.
  2. Engine misfire is detected and DTC P0300 set.

DTCs P1380 and P1381 are Type C DTCs.

DTCs P1380 and P1381 are Type C DTCs.

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Monitor the ABS DTCs on the scan tool.

  1. If any ABS DTCs are set, diagnose those first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. If there are no ABS DTCs set, refer to «Symptoms - Antilock Brake System»(/chevrolet/express-g3500/2013-2013/remont/anti-locktraction-control/#antilock-brake-system) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The catalytic converter must be warmed to efficiently reduce the emissions. The cold start strategy is to reduce the amount of time it takes to warm the catalytic converter. During a cold start, the engine idle speed is elevated and spark timing is retarded to allow the catalyst to warm quickly. This diagnostic monitors the following to build an exhaust energy model

  1. Engine speed
  2. Spark advance
  3. Throttle position
  4. Engine airflow
  5. Engine coolant temperature
  6. Engine runtime
  7. Park/neutral position
  8. Vehicle speed

The actual model is then compared to the expected exhaust energy model.

  1. The engine is running, and a cold start has been detected.
  2. Vehicle speed is less than 2 km/h (1 mph).
  3. The engine is at idle with no input from the accelerator pedal.
  4. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0201, P0202, P0203, P0204, P0205, P0206, P0300, P0335, P0336, P0351, P0352, P0353, P0501, P0502, P0506, P0507, P0601, P0602, P0603, P0604, P0606, P0607, P060D, P062F, P0641, P0651, P1101, P1516, P1682, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, P2610 are not set.

This DTC runs for 15 seconds within the first 2 minutes of start-up. This diagnostic runs once per trip when a cold start has been determined.

The actual exhaust energy model does not match the expected exhaust energy model.

DTC P1400 is a Type A DTC.

DTC P1400 is a Type A DTC.

Description and Operation

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Any loading of the engine that lowers engine RPM, such as with partial application of the clutch, A/C cycling etc., during the first 120 seconds of engine runtime may set this DTC.

  1. Allow the engine to cool.
  2. Start and idle the engine for at least 2 minutes.
  3. DTC P1400 should run and pass.
  1. Inspect the air intake system for the following: Damage, restriction, or modification Dirty or deteriorating air filter element Crankcase ventilation system for correct operation-Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) . Water intrusion Vacuum leak and other un-metered air downstream of the mass air flow (MAF) sensor Intake manifold leak
  2. Inspect the exhaust system for the following: Water intrusion Exhaust leak Damaged, restricted, modified or enhanced exhaust system-Refer to «Symptoms - Engine Exhaust»(/chevrolet/express-g3500/2013-2013/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) .
  3. Inspect the engine mechanical for items that could alter the air flow into the combustion chamber. Refer to «Symptoms - Engine Mechanical»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

To improve vehicle shift feel, the transmission control module (TCM) is constantly sending the ECM serial data messages with information regarding its request for modifying engine speed or torque. The ECM sets this code when it detects a discrepancy in the structure of this message causing its integrity to be questioned.

An intermittent fault in the controller area network (CAN) circuits will cause DTC P150C to set.

  1. DTCs P0506, P0507, or U0101 are not set.
  2. The engine is running 0.5 s.
  3. The DTC runs continuously when the above conditions are met.

The ECM detects that the TCM engine speed request does not match the expected engine speed request.

DTC P150C is a Type B DTC.

DTC P150C is a Type B DTC.

Description and Operation

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Note. DTC P150C is an informational DTC. Diagnose all other engine control module DTCs prior to DTC P150C.

  1. Verify that no other DTCs are set except for DTC P150C. If any other DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If only DTC P150C is set
  2. Replace the K17 Electronic Brake Control Module.
  3. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.
  4. Verify the DTC does not set. If the DTC sets Replace the K20 Engine Control Module. If the DTC does not set
  5. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for ECM or control solenoid valve assembly replacement, programming, and setup.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
TAC Motor Control ClosedP1516, P2101, P2176P1516, P2101, P2176P1516, P2101, P2176P1516, P2101, P2176
TAC Motor Control OpenP1516, P2101, P2176P1516, P2101, P2176P1516, P2101, P2176P1516, P2101, P2176

The Engine Control Module (ECM) controls the throttle valve by applying a varying voltage to the control circuits of the throttle actuator control (TAC) motor. The ECM monitors the duty cycle that is required to actuate the throttle valve. The ECM monitors the throttle position (TP) sensors 1 and 2 to determine the actual throttle valve position.

P1516

  1. DTC P1682 is not set.
  2. The run/crank or powertrain relay voltage is greater than 6.0 V and reduced power is not active.
  3. DTC P1516 runs continuously when the above conditions are met.

P2101

  1. DTC P1682 is not set.
  2. The run/crank or powertrain relay voltage is greater than 6.0 V and reduced power is not active.
  3. The engine is running or the following conditions are met: The engine is not running. The ignition voltage is greater than 11 V. The TAC system is not in the Battery Saver mode. The ECM is commanding the throttle. The ECM has learned the minimum throttle position.
  4. DTC P2101 runs continuously when the above conditions are met.

P2119

  1. DTC P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0651, or P2135 is not set.
  2. The ignition is ON.
  3. The run/crank or powertrain relay voltage is greater than 5.5 V and reduced power is not active.
  4. DTC P2119 runs continuously when the above conditions are met.

P2176

  1. DTCs P0120, P0121, P0122, P0123, P0220, P0222, P0223, P1682, or P2135 is not set.
  2. The ignition is ON.
  3. The run/crank or powertrain relay voltage is greater than 6.0 V and reduced power is not active.
  4. The ECM enable the minimum throttle learn procedure.
  5. DTC P2176 run continuously when the above conditions are met.

P1516

The ECM detects an unstable throttle position for greater than 0.2 s.

P2101

The ECM detects the actual throttle position does not match the predicted throttle position for greater than 1 s.

P2119

The ECM detects the throttle blade did not return to the default position when the TAC motor is de-energized for greater than 0.5 s.

P2176

The ECM detects that both throttle position (TP) sensors were greater than a predetermined voltage during the minimum throttle learn procedure for greater than 2 s.

  1. DTCs P1516, P2101, and P2176 are Type A DTCs.
  2. DTC P2119 is a Type C DTC.
  3. The control module commands the TAC system to operate in the Reduced Engine Power mode.
  4. A message center or an indicator displays Reduced Engine Power.
  5. Under certain conditions, the control module commands the engine OFF.
  1. DTCs P1516, P2101, and P2176 are Type A DTCs.
  2. DTC P2119 is a Type C DTC.
  1. Depending on the Start Up ECT, the Desired Throttle Position percentage maybe greater or less than the Throttle Position with the TAC motor at rest. When the ignition is initially turned ON, or when the engine is cranking or running the Desired and Actual Throttle positions should closely match.
  2. Inspect for a condition in which the throttle valve may have been held open. For example, ice may have formed in the throttle bore causing the throttle valve not to close.
  3. A high resistance condition on the throttle position and throttle actuator control circuits could cause a DTC to set.
  4. A low battery condition may cause a DTC to set.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify DTC P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0562, P0621, P0622, or P2135 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If none of the DTCs are set
  3. Verify the scan tool TB Idle Airflow Compensation parameter is less than 90 %. If 90 % or greater Refer to «Throttle Body Cleaning»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-repair-instructions__throttle-body-cleaning) . If less than 90 %
  4. Clear the DTCs with a scan tool.
  5. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down.
  6. Ignition ON.
  7. Verify the scan tool TAC Motor parameter displays Enabled while slowly depressing the accelerator pedal. If Enabled is not displayed Refer to Circuit/System Testing. If Enabled is displayed
  8. Verify DTC P1516, P2101, P2119, or P2176 is not set. If any of the DTCs are set Refer to Circuit/System Testing. If none of the DTCs are set
  9. Verify the scan tool TAC Motor parameter displays Enabled while performing the Throttle Sweep Test with a scan tool. If Enabled is not displayed Test or replace the Q38 Throttle Body Assembly. If Enabled is displayed
  10. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  11. Verify a DTC does not set. If any DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If no DTCs set
  12. All OK.
  1. Ignition OFF.
  2. Verify the conditions listed below do not exist with the Q38 Throttle Body Assembly: NOTE: The rest position is defined as the actual Throttle Position percentage when the ignition is OFF or with the ignition ON for greater than 30 seconds. When the ignition is OFF, spring tension should hold the throttle plate in the rest position. You should be able to open the throttle plate to wide open throttle (WOT) or push the throttle plate to the fully closed position. In each case, the throttle plate should return to the rest position without assistance. A throttle blade that is not in the rest position A throttle blade that is binding open or closed A throttle blade that is free to move open or closed without spring pressure If a condition is found Test or replace the Q38 Throttle Body Assembly. If a condition is not found
  3. Ignition OFF.
  4. Disconnect the harness connector at the Q38 Throttle Body Assembly, ignition ON.
  5. Verify that a test lamp does not illuminate between each motor control circuit listed below and ground. TAC Motor Control Closed circuit terminal A TAC Motor Control Open circuit terminal B If the test lamp illuminates Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON Test for less than 1 V between the control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If the test lamp is always OFF
  6. Verify that a test lamp does not illuminate between each motor control circuit listed below and B+. TAC Motor Control Closed circuit terminal A TAC Motor Control Open circuit terminal B If the test lamp illuminates Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K20 Engine Control Module. If the test lamp is always OFF
  7. Ignition OFF, set the DMM to the 40 V scale, select the Min/Max Recording Mode, and set the Peak Min/Max response time to 1 ms.
  8. Verify the Max voltage is within 3 V of B+ while using DMM Min/Max Recording Mode function on each control circuit listed below as the ignition is turned ON. TAC Motor Control Closed circuit terminal A TAC Motor Control Open circuit terminal B If not within 3 V of B+ Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If within 3 V of B+
  9. Test or replace the Q38 Throttle Body Assembly.
  1. «Throttle Body Assembly Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Engine Control Module replacement, programming, and setup
  1. Ignition OFF.
  2. Install any components that have been removed or replaced during diagnosis.
  3. Perform any adjustments, programming or setup procedures that are required when a component is removed or replaced.
  4. Ignition ON.
  5. Clear the DTCs with a scan tool.
  6. Turn the ignition OFF for 60 s.
  7. Ignition ON.
  8. Verify the scan tool TAC Motor parameter displays Enabled while performing the Throttle Sweep Test with a scan tool. If Enabled is not displayed Test or replace the Q38 Throttle Body Assembly. If Enabled is displayed
  9. If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not set. If DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If DTC does not set
  10. All OK.
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Fuel trim bias is used to keep the post catalyst air/fuel ratio within a predetermined range. This allows optimal catalyst efficiency under various operating conditions. The engine control module (ECM) constantly monitors how lean or rich the fuel trim bias is commanded, to determine if the fuel trim bias is greater than a calibrated amount.

  1. DTC P0016, P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0116, P0117, P0118, P0128, P0131-P0135, P0137, P0138, P013A-P013F, P0140, P0141, P014A, P014B, P0151-P0155, P0157, P0158, P015A-P015D, P0160, P0161, P0178, P0179, P0201-P0206, P0300, P0301-P0306, P0340, P0341, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P1133, P1153, P219A, P219B, P2227, P2228, P2229, P2269, P2270, P2271, P2272, or P2273 is not set.
  2. The barometric pressure (BARO) is greater than 70 kPa (10.2 PSI).
  3. The manifold absolute pressure (MAP) is between 0-200 kPa (0-29 PSI).
  4. The intake air temperature (IAT) is between -20 and +200°C (-4 and +392°F).
  5. The engine coolant temperature is warmer than -20°C (-4°F).
  6. The engine is in closed loop status.
  7. The fuel control intrusive diagnostics are not active.
  8. The power take-off is not active, if equipped.
  9. DTCs P2096 and P2098 run continuously when the conditions above have been met.

The lean correction limit for a condition causing a rich air/fuel ratio has been exceeded.

  1. DTCs P2096 and P2098 are Type B DTCs.
  2. The ECM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the ECM stores this information in the Failure records. If the diagnostic reports a failure on the second ignition cycle, the ECM records the operating conditions at the time of the failure. The ECM writes the operating conditions to the Freeze Frame and updates the Failure records. The ECM illuminates the malfunction indicator lamp (MIL) when one of the following occurs: The ECM detects the same fuel trim failure during 2 consecutive trips. The ECM detects any fuel trim failure during any subsequent trip if the conditions at the time of failure meet the following criteria: The engine load is within 20 percent of the previous test that failed. The engine speed is within 375 RPM of the previous test that failed. The engine coolant temperature is in the same range of the previous test that failed.
  1. DTCs P2096 and P2098 are Type B DTCs.
  2. The ECM turns OFF the malfunction indicator lamp (MIL) at the beginning of the fourth ignition cycle, after 3 ignition cycles that the diagnostic runs and does not fail.
  3. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  1. The post catalyst fuel trim diagnostic is very sensitive to heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part number may cause a DTC to set.
  2. Certain aftermarket air filters may cause a DTC to set.
  3. Certain aftermarket air induction systems or modifications to the air induction system may cause a DTC to set.
  4. Certain aftermarket exhaust system components may cause a DTC to set.

Schematic Reference

Connector End View Reference

Component View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, verify there is no other HO2S or fuel trim DTC set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. Ignition OFF, verify that none of the conditions listed below exist: Collapsed or restricted air intake duct. Dirty or restricted air filter. Objects blocking the throttle body. Excessive fuel in the crankcase. Change the engine oil as necessary. Rich fuel injectors. Refer to «Fuel Injector Diagnosis (CH47976)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (J39021 or Tech 2)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . High fuel system pressure. Refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Contaminated fuel. Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Fuel saturation of the evaporative emissions (EVAP) canister Stuck open or leaking evaporative emissions purge valve. Restricted exhaust. Refer to «Symptoms - Engine Exhaust»(/chevrolet/express-g3500/2013-2013/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) . Incorrect PCV system operation. Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) . If a condition is found, repair as necessary.
  3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Perform the Diagnostic Repair Verification after completing the repair.

Reset the fuel trim after completing the repair.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Fuel trim bias is used to keep the post catalyst air/fuel ratio within a predetermined range. This allows optimal catalyst efficiency under various operating conditions. The engine control module (ECM) constantly monitors how lean or rich the fuel trim bias is commanded, to determine if the fuel trim bias is greater than a calibrated amount.

  1. DTC P0016, P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0131-P0135, P0137, P0138, P013A-P013F, P0140, P0141, P014A, P014B, P0151-P0155, P0157, P0158, P015A-P015D, P0160, P0161, P0178, P0179, P0201-P0206, P0300, P0301-P0306, P0340, P0341, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P1133, P1153, P219A, P219B, P2227, P2228, P2229, P2269, P2270, P2271, P2272, or P2273 is not set.
  2. The barometric pressure (BARO) is greater than 70 kPa (10.2 PSI).
  3. The manifold absolute pressure (MAP) is between 0-200 kPa (0-29 PSI).
  4. The intake air temperature (IAT) is between -20 and +200°C (-4 and +392°F).
  5. The engine coolant temperature is warmer than -20°C (-4°F).
  6. The engine is in closed loop status.
  7. The fuel control intrusive diagnostics are not active.
  8. The power take-off is not active, if equipped.
  9. DTCs P2097 and P2099 run continuously when the conditions above have been met.

The rich correction limit for a condition causing a lean air/fuel ratio has been exceeded.

  1. DTCs P2097 and P2099 are Type B DTCs.
  2. The ECM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the ECM stores this information in the Failure records. If the diagnostic reports a failure on the second ignition cycle, the ECM records the operating conditions at the time of the failure. The ECM writes the operating conditions to the Freeze Frame and updates the Failure records. The ECM illuminates the malfunction indicator lamp (MIL) when one of the following occurs: The ECM detects the same fuel trim failure during 2 consecutive trips. The ECM detects any fuel trim failure during any subsequent trip if the conditions at the time of failure meet the following criteria: The engine load is within 20 percent of the previous test that failed. The engine speed is within 375 RPM of the previous test that failed. The engine coolant temperature is in the same range of the previous test that failed.
  1. DTCs P2097 and P2099 are Type B DTCs.
  2. The ECM turns OFF the malfunction indicator lamp (MIL) at the beginning of the fourth ignition cycle, after 3 ignition cycles that the diagnostic runs and does not fail.
  3. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  1. The post catalyst fuel trim diagnostic is very sensitive to heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part number may cause a DTC to set.
  2. An exhaust system leak that may not be audible can set this DTC.
  3. Certain aftermarket air filters may cause a DTC to set.
  4. Certain aftermarket air induction systems or modifications to the air induction system may cause a DTC to set.
  5. Certain aftermarket exhaust system components may cause a DTC to set.

Schematic Reference

Connector End View Reference

Component View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, verify there is no other HO2S or fuel trim DTC set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. Ignition OFF, verify that none of the conditions listed below exist: Exhaust system leaks. Refer to «Symptoms - Engine Exhaust»(/chevrolet/express-g3500/2013-2013/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) . Split, kinked, or improperly connected vacuum hoses. Insufficient fuel in the tank. Leaks in the air induction system or the air intake ducts. Missing air filter element. A cracked evaporative emissions canister. Plugged, obstructed, or leaking evaporative emissions system pipes. Leaks in the crankcase ventilation system. Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) . Engine vacuum leaks. Low fuel system pressure. Refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Contaminated fuel. Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Lean fuel injectors. Refer to «Fuel Injector Diagnosis (CH47976)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (J39021 or Tech 2)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . If a condition is found, repair as necessary.
  3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Perform the Diagnostic Repair Verification after completing the repair.

Reset the fuel trim after completing the repair.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
APP Sensor 1 5 V ReferenceP0651P2138P2122P0651P2138
APP Sensor 2 5 V ReferenceP0108, P0641P2138P2127P0107, P0522, P0532, P0641P2138
APP Sensor 1 SignalP2122P2138P2122P2123P2138
APP Sensor 2 SignalP2127P2138P2127P2128P2138
APP Sensor 1 Low ReferenceP2138P2123P2138
APP Sensor 2 Low ReferenceP2138P2128P2138
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: The engine is operating at idle. Parameter Normal Range: APP Sensor 1 0.88-1.08 V
APP Sensor 1 5 V Reference0.00 V0.00 V2-4 V
APP Sensor 1 Signal0.00 V0.00 V4-5 V
APP Sensor 1 Low Reference4-5 V

APP Sensor 1

CircuitShort to GroundOpenShort to Voltage
Operating Conditions: The engine is operating at idle. Parameter Normal Range: APP Sensor 2 0.39-0.59 V
APP Sensor 2 5 V Reference0.00 V0.00 V1-3 V
APP Sensor 2 Signal0.00 V0.00 V2-5 V
APP Sensor 2 Low Reference4-5 V

APP Sensor 2

The accelerator pedal assembly contains 2 accelerator pedal position (APP) sensors. The APP sensors are mounted to the accelerator pedal assembly and are not serviceable. The APP sensors provide a signal voltage that changes relative to pedal position. The engine control module (ECM) supplies each APP sensor with a 5 V reference circuit, a low reference circuit, and a signal circuit.

P2120, P2122, P2123, P2125, P2127, P2128

  1. DTC P0641 and P0651 are not set.
  2. The ignition is ON or the engine is running.
  3. The run/crank or powertrain relay voltage is greater than 6.0 V and reduced power is not active.
  4. DTC 2120, P2122, P2123, P2125, P2127, P2128 run continuously when the above conditions are met.

P2138

  1. DTC P0641, P0651, P2120, P2122, P2123, P2125, P2127, and P2128 are not set.
  2. The ignition is ON or the engine is running.
  3. The run/crank or powertrain relay voltage is greater than 6.0 V and reduced power is not active.
  4. DTC P2138 runs continuously when the above conditions are met.

P2120

The ECM detects the APP sensor 1 voltage is less than 0.46 V or greater than 4.75 V for greater than 1 s.

P2122

The ECM detects the APP sensor 1 voltage is less than 0.46 V for greater than 1 s.

P2123

The ECM detects the APP sensor 1 voltage is greater than 4.75 V for greater than 1 s.

P2125

The ECM detects the APP sensor 2 voltage is less than 0.32 V or greater than 2.6 V for greater than 1 s.

P2127

The ECM detects the APP sensor 2 voltage is less than 0.32 V for greater than 1 s.

P2128

The ECM detects the APP sensor 2 voltage is greater than 2.6 V for greater than 1 s.

P2138

The ECM detects the voltage difference between APP sensor 1 and APP sensor 2 exceeds a predetermined value for greater than 1 s.

  1. DTCs P2120, P2122, P2123, P2125, P2127, P2128, and P2138 are Type A DTCs.
  2. The control module commands the TAC system to operate in the Reduced Engine Power mode.
  3. A message center or an indicator displays Reduced Engine Power.
  4. Under certain conditions the control module commands the engine OFF.

DTCs P2120, P2122, P2123, P2125, P2127, P2128, and P2138 are Type A DTCs.

A high resistance condition on the accelerator pedal sensor circuits could cause a DTC to set.

Ensure that the in-line harness connector seals are installed correctly. Improper installation could result in water intrusion into the connector and cause a DTC to set.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify DTC P0641 or P0651 is not set. If any of the DTCs are set Refer to «DTC P0641 or P0651 (ECM)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) for further diagnosis. If none of the DTCs are set
  3. Verify the scan tool APP Sensor 1 voltage parameter is between 0.46-4.75 V and changes with accelerator pedal input. If not between 0.46-4.75 V or does not change Refer to Circuit/System Testing If between 0.46-4.75 V and changes
  4. Verify the scan tool APP Sensor 2 voltage parameter is between 0.32-2.6 V and changes with accelerator pedal input. If not between 0.32-2.6 V or does not change Refer to Circuit/System Testing If between 0.32-2.6 V and changes
  5. Verify the scan tool APP Sensor 1 and 2 Agree/Disagree parameter displays Agree while performing the tests listed below: Rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release pedal. Repeat the procedure several times. Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times. If Disagree Refer to Circuit/System Testing If Agree
  6. Verify that DTC P2120, P2122, P2123, P2125, P2127, P2128, or P2138 is not set. If any of the DTCs are set Refer to Circuit/System Testing If none of the DTCs set
  7. Clear the DTCs with the scan tool. Operate the vehicle within the Conditions for Running the DTC, or within the conditions that you observed from the Freeze Frame/Failure Records.
  8. Ignition ON.
  9. Verify DTC P2120 or P2125 are not the only APP sensor DTCs set. If DTC P2120 or P2125 are the only DTCs set Replace the K20 Engine Control Module. If DTC P2120 or P2125 are not set
  10. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  11. Verify a DTC does not set. If any DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If no DTCs set
  12. All OK
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B107 Accelerator Pedal Position Sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the appropriate low reference circuit terminal listed below and ground. APP Sensor 1 low reference circuit terminal D APP sensor 2 low reference circuit terminal E If 5 ohms or greater Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If less than 5 ohms
  3. Ignition ON.
  4. Test for 4.8-5.2 V between the appropriate 5 V reference circuit terminal listed below and ground. APP Sensor 1 5 V reference circuit terminal B APP Sensor 2 5 V reference circuit terminal A If less than 4.8 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the 5 V reference circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the 5 V reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 5.2 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the 5 V reference circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If between 4.8-5.2 V
  5. Verify the scan tool APP sensor 1 and APP sensor 2 voltage parameters are less than 0.3 V. If 0.3 V or greater Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal listed below and ground. APP Sensor 1 signal circuit terminal C APP Sensor 2 signal circuit terminal F If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If less than 0.3 V
  6. Install a 3 A fused jumper wire between the appropriate signal circuit terminal listed below and the 5 V reference circuit terminal C or 1. APP Sensor 1 signal circuit terminal C APP Sensor 2 signal circuit terminal F
  7. Verify the scan tool APP sensor 1 or APP sensor 2 voltage parameter is greater than 4.8 V. If 4.8 V or less Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit terminal and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 4.8 V
  8. Test or replace the B107 Accelerator Pedal Position Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Accelerator Pedal Position Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-repair-instructions)
  2. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The Fuel Trim Cylinder Balance diagnostic detects a rich or lean cylinder to cylinder air/fuel ratio imbalance in each bank. The diagnostic monitors the pre-catalyst heated oxygen sensor (HO2S) signal's frequency and amplitude characteristics by calculating an accumulated voltage over a predetermined sample period. An imbalance is indicated when multiple samples of the accumulated voltage are consistently higher than the desired value.

  1. DTCs P0030, P0050, P0053, P0059, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0122, P0123, P0128, P0131-P0135, P0151- P0155, P015A-P015D, P0178, P0179, P0201-P0206, P0220, P0222, P0223, P0300, P0301-P0306, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P1133, P1153, P1516, P2135, P2176, P2269 are not set.
  2. A scan tool device control is not active.
  3. The intrusive diagnostics are not active.
  4. The engine overspeed protection is not active.
  5. The power take-off is not active.
  6. The traction control is not active.
  7. The engine is in closed loop status.
  8. The system voltage is between 10-32 V for greater than 4 s.
  9. The engine run time is greater than 100 s.
  10. The engine coolant temperature (ECT) is warmer than -20°C (-4°F).
  11. The engine speed is between 425-2,500 RPM.
  12. The mass air flow is between 15-65 g/s.
  13. The fuel ethanol content is less than 87 percent.
  14. The DTCs run continuously when the above conditions have been met.

Multiple samples of the pre-catalyst HO2S accumulated voltage are consistently greater than the desired value.

DTCs P219A and P219B are Type B DTCs.

DTCs P219A and P219B are Type B DTCs.

  1. The fuel trim cylinder balance diagnostic is very sensitive to heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part number may cause a DTC to set.
  2. Monitoring the misfire current counters, or misfire graph, may help to isolate the cylinder that is causing the condition.
  3. Certain aftermarket air filters may cause a DTC to set.
  4. Certain aftermarket air induction systems or modifications to the air induction system may cause a DTC to set.
  5. Certain aftermarket exhaust system components may cause a DTC to set.

Schematic Reference

Connector End View Reference

Component View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Troubleshooting with a Test Lamp»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__troubleshooting-with-a-test-lamp)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, verify there are no other DTCs set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.
  2. Engine idling, verify the Manifold Absolute Pressure Sensor parameter is between 19-42 kPa (2.7-6 PSI). If not within the specified range, refer to «DTC P0106»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) , or «DTC P0107 or P0108»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  3. Ignition OFF, verify that none of the conditions listed below exists: Modified, damaged, leaking, or restricted air induction system components. Improper operation of the crankcase ventilation system. Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) . Split, kinked, or improperly connected vacuum hoses. Restricted, damaged, leaking, or modified exhaust system from the catalytic converter forward. Refer to «Symptoms - Engine Exhaust»(/chevrolet/express-g3500/2013-2013/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) . Vacuum leaks at the intake manifold, the throttle body, or the injector O-rings. Improper operation of the fuel injectors. Refer to «Fuel Injector Diagnosis (CH47976)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (J39021 or Tech 2)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Fuel contamination. Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Excessive fuel in the crankcase due to leaking injectors. Improper operation of the ignition system. Refer to «Electronic Ignition System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . If a condition is found, repair as necessary.
  4. If all the above conditions test normal, test the engine for any mechanical conditions which could alter the flow into the combustion chamber. Refer to «Symptoms - Engine Mechanical»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) .

Perform the Diagnostic Repair Verification after completing the repair.

Reset the fuel trim after completing the repair.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
HO2S SignalP0131, P0132, P0137, P0140, P0151, P0152, P0157, P0158, P1133P0131, P0132, P0133, P0134, P0137, P013A, P013B, P013E, P013F, P0140, P0151, P0152, P0153, P0154, P0157, P0160, P1133, P1153P0131, P0132, P0133, P0134, P0137, P013A, P013B, P013E, P013F, P0140, P0151, P0152, P0153, P0154, P0157, P0160, P1133, P1153P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160, P1133, P1153P0133, P0134, P013A, P013B, P013E, P013F, P0140, P0153, P0154, P0160, P1133, P1153, P2270, P2271
HO2S Low ReferenceP0131, P0132, P0133, P0134, P0138, P013A, P013B, P013E, P013F, P0140, P0151, P0152, P0153, P0154, P0158, P0160, P1133P0131, P0132, P0133, P0134, P0138, P013A, P013B, P013E, P013F, P0140, P0151, P0152, P0153, P0154, P0158, P0160, P1133, P1153P0134, P0138, P0140, P0154, P0158, P0160, P1133, P1153
CircuitShort to GroundOpenShort to Voltage
Parameter Normal Range: 200-800 mV
HO2S Signal0 mVApproximately 470 mVApproximately 1,100 mV
HO2S Low Reference455 mVApproximately 450 mVApproximately 445 mV

HO2S Bank 1 or 2 Sensor 2 Voltage

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the engine control module (ECM) operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,275 mV. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.

The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the control module to calculate the air-to-fuel ratio sooner.

  1. DTCs P0036, P0037, P0038, P0137, P0138, P0140, P0141, P0443, P0458, P0459, P2232 are not set.
  2. The ignition 1 voltage is between 10-32 volts.
  3. The engine run time is greater than 5 minutes.
  4. The engine speed is between 1,000-2,550 RPM.
  5. The mass air flow (MAF) is between 3-20 g/s.
  6. The vehicle speed is between 71-120 km/h (44-75 mph).
  7. Evap is not in control of purge.
  8. HO2S heater is on for greater than 100 s.
  9. Power Take Off Mode is not active.
  10. EGR Intrusive diagnostic is not active.
  11. The fuel level is greater than 10 percent.
  12. The fuel system is in Closed Loop.
  13. The catalytic converter temperature is between 600-900°C (1,112-1,652°F).
  14. The DTCs run once per ignition cycle when the above conditions are met.

P2270

The ECM does not detect a HO2S voltage greater than 805 mV before accumulated mass air flow exceeds a calibrated value.

P2272

The ECM does not detect a HO2S voltage greater than 775 mV before the accumulated mass air flow exceeds a calibrated value.

DTCs P2270 and P2272 are Type B DTCs.

DTCs P2270 and P2272 are Type B DTCs.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the DTC information with a scan tool. Verify that no HO2S heater DTCs are set. If any HO2S heater DTCs are set, perform those diagnostics first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. Engine running, observe the appropriate scan tool HO2S Bank 1 or 2 Sensor 1 or 2 voltage parameter. The reading should be within the range of 50-1,050 mV.
  3. Move the related wiring and connectors while observing the HO2S Heater parameter with a scan tool. The parameter should not change with movement. If movement affects the parameter, repair the appropriate harness or connector.
  4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate B52 HO2S. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference circuit terminal A and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  3. Ignition ON, verify the appropriate scan tool B52 HO2S parameter is approximately 450 mV. If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM. If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  4. Install a 3 A fused jumper wire between the signal circuit terminal B and ground. Verify the scan tool HO2S parameter is less than 60 mV. If greater than the specified range, test the signal circuit for an open/high resistance. If the circuits test normal, replace the ECM.
  5. Verify none of the following conditions exist: Lean fuel injectors-Refer to «Fuel Injector Diagnosis (LC8\FHZ)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (J 39021 or Tech 2)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (CH47976)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (LC8\K07)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) Water intrusion in the B52 HO2S harness connector Low fuel system pressure-Refer to «Fuel System Diagnosis (Without FPCM)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (LC8\K07\UFP)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (LC8\FHZ)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (FPCM)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (LC8\K07\UFM)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) Fuel that is contaminated-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) Exhaust leaks Engine vacuum leaks Contaminated B52 HO2S - Silicon An engine mechanical condition- «Symptoms - Engine Mechanical»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-48l-l20-53l-lmf-or-60l-l96-lc8-diagnostic-information-and-procedures) If you find any of the above conditions, repair as necessary.
  6. If all circuits test normal, replace the appropriate B52 HO2S.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 2»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  3. Perform the scan tool Heated Oxygen Sensor Resistance Learn Reset after replacing a HO2S.
  4. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
HO2S High SignalP0131, P0132, P0137, P0140, P0151, P0152, P0157, P0158, P1133P0131, P0132, P0133, P0134, P0137, P013C, P013D, P0140, P014A, P014B, P0151, P0152, P0153, P0154, P0157, P0160, P1133, P1153P0131, P0132, P0133, P0134, P0137, P013C, P013D, P0140, P014A, P014B, P0151, P0152, P0153, P0154, P0157, P0160, P1133, P1153P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160, P1133, P1153P0133, P0134, P013C, P013D, P0140, P014A, P014B, P0153, P0154, P0160, P1133, P1153, P2272, P2273
HO2S Low SignalP0131, P0132, P0133, P0134, P0138, P013C, P013D, P0140, P014A, P014B, P0151, P0152, P0153, P0154, P0158, P0160, P1133P0131, P0132, P0133, P0134, P0138, P013C, P013D, P0140, P014A, P014B, P0151, P0152, P0153, P0154, P0158, P0160, P1133, P1153P0134, P0138, P0140, P0154, P0158, P0160, P1133, P1153
CircuitShort to GroundOpenShort to Voltage
Parameter Normal Range: 200-800 mV
HO2S High Signal0 mVApproximately 470 mVApproximately 1,100 mV
HO2S Low Signal455 mVApproximately 450 mVApproximately 445 mV

HO2S Bank 1 or 2 Sensor 2 Voltage

Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The engine control module (ECM) supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started, the control module operates in Open Loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and Closed Loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream. Low HO2S voltage indicates a lean exhaust stream.

  1. Before the ECM can report DTC P2271, or P2273 failed, DTCs P013A, P013C, P013E, P014A, P2270, and P2272 must run and pass.
  2. DTCs P0036, P0037, P0038, P0137, P0138, P0140, P0141, P0443, P0458, P0459, P2232 are not set.
  3. The ignition voltage is between 10-32 volts.
  4. The engine speed is between 500-5,000 RPM.
  5. The mass air flow (MAF) is between 3-20 g/s.
  6. The vehicle speed is between 24-132 km/h (15-82 mph).
  7. The fuel level is greater than 10 percent.
  8. The fuel system is in Closed Loop.
  9. Evap is not in control of purge.
  10. Power Take Off is not active.
  11. EGR Intrusive diagnostic is not active.
  12. The DTCs run once per ignition cycle, during decel fuel cut-off, when the above conditions are met.

P2271

The ECM does not detect an HO2S voltage less than 150 mV before accumulated mass air flow exceeds a calibrated value.

P2273

The ECM does not detect an HO2S voltage less than 100 mV before the accumulated mass air flow exceeds a calibrated value.

DTCs P2271 or P2273 are Type B DTCs.

DTCs P2271 or P2273 are Type B DTCs.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the DTC information with a scan tool. Verify that no HO2S heater DTCs are set. If any HO2S heater DTCs are set, perform those diagnostics first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. Engine running, observe the appropriate scan tool HO2S Bank 1 or 2 Sensor 1 or 2 voltage parameter. The reading should be within the range of 50-1,050 mV.
  3. Move the related wiring and connectors while observing the HO2S Heater parameter with a scan tool. The parameter should not change with movement. If movement affects the parameter, repair the appropriate harness or connector.
  4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate B52 HO2S. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference circuit terminal A and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  3. Ignition ON, verify the appropriate scan tool B52 HO2S parameter is approximately 450 mV. If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM. If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
  4. Install a 3 A fused jumper wire between the signal circuit terminal B and ground. Verify the scan tool B52 HO2S parameter is less than 60 mV. If greater than the specified range, test the signal circuit for an open/high resistance. If the circuits test normal, replace the K20 ECM.
  5. Verify none of the following conditions exist: Rich fuel injectors-Refer to «Fuel Injector Diagnosis (LC8\FHZ)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (J 39021 or Tech 2)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (CH47976)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (LC8\K07)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) Water intrusion in the B52 HO2S harness connector High fuel system pressure-Refer to «Fuel System Diagnosis (Without FPCM)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (LC8\K07\UFP)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (LC8\FHZ)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (FPCM)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (LC8\K07\UFM)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) Fuel that is contaminated-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) Fuel saturation of the evaporative emission (EVAP) canister If you find any of the above conditions, repair as necessary.
  6. If all circuits test normal, replace the appropriate B52 HO2S.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-repair-instructions)
  2. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 2»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-repair-instructions)
  3. Perform the scan tool Heated Oxygen Sensor Resistance Learn Reset after replacing a HO2S.
  4. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for a overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

To improve shift feel, the transmission control module (TCM) is constantly sending the engine control module (ECM) serial data messages with information regarding it's request for modifying engine speed or torque. The serial data messages are sent through two circuits which are part of a communication network called the controller area network (CAN). The ECM sets DTC P2544 when it detects a discrepancy in the structure of the message causing the integrity of the message to be questioned.

  1. The engine run time is greater than 0.5 s.
  2. No other CAN errors are present.

The ECM detects that the engine speed and torque modification messages from the TCM are either corrupted or intermittently missing for greater than 4 s.

  1. DTC P2544 is a Type B DTC.
  2. The TCM commands maximum line pressure during shifts, which results in harsh shifts.
  3. The TCM freezes adaptive functions.

DTC P2544 is a Type B DTC.

An intermittent fault in the CAN circuits will cause the ECM to set DTC P2544.

DTC Type Reference

Note. DTC 2544 is an informational DTC. Diagnose all other engine control module DTCs prior to DTC 2544.

  1. Verify that no other DTCs are set except for DTC 2544. If any other DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) If only DTC P2544 is set
  2. Replace the K17 Electronic Brake Control Module.
  3. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.
  4. Verify the DTC does not set. If DTC sets Replace the K20 Engine Control Module. If DTC does not set
  5. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for ECM or control solenoid valve assembly replacement, programming, and setup.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Symptoms Description

Symptoms cover conditions that are not by covered DTCs. Certain conditions can cause multiple symptoms. These conditions are listed together under Symptoms Testing. Conditions that may only cause certain symptoms are listed separately under Additional Symptoms Test. Perform the Symptoms Testing before using the Additional Symptoms Tests. Poor Fuel Fill Quality test may be performed separately from the Symptoms Testing and Additional Symptoms Tests procedures.

Symptoms Verification

Before using the Symptom tables, perform the following inspections

  1. Verify that the engine control module (ECM) and malfunction indicator lamp (MIL) are operating correctly.
  2. Verify that there are no diagnostic trouble codes (DTCs) that are stored.
  3. Verify that the scan tool data is within a normal operating range.
  4. Verify the customer concern.
  5. Perform the Visual/Physical Inspection in this section. The visual/physical inspection is extremely important, and can lead to correcting a condition without additional testing. It may also help reveal the cause of an intermittent condition.

Identifying Intermittent Conditions

Many intermittent conditions occur with harness or connector movement due to engine torque, rough pavement, vibration or physical movements of a component. Refer to the following for a list of issues that may cause an intermittent condition

  1. Moisture and water intrusion in connectors, terminals, and components
  2. Incomplete connector mating
  3. Poor terminal contact
  4. High circuit or component resistance-High resistance can include any resistance, regardless of the amount, which can interrupt the operation of the component.
  5. Harness that is too short or tight.
  6. Wire insulation that is chaffed or cut.
  7. High or low ambient temperature
  8. High or low engine coolant temperatures
  9. High underhood temperatures
  10. Heat build up in component or circuit due to circuit resistance, poor terminal contact, or high electrical load
  11. High or low system voltage
  12. High vehicle load conditions
  13. Rough road surfaces
  14. Electro-magnetic interference (EMI)/circuit interference from relays, solenoids or other electrical surge
  15. Incorrect installation of aftermarket, add on accessories

Visual/Physical Check

  1. Verify that the control module grounds are clean, tight, and correctly located.
  2. Verify that the vacuum hoses are not split or kinked, and are properly connected, as shown on the Vehicle Emission Control Information label.
  3. Verify that the air filter is clean and free from restrictions.
  4. Verify that there is no water intrusion in connectors terminals and components.
  5. Inspect the air intake ducts for the following conditions: Collapsed Damaged areas Looseness Incorrect installation Leaking
  6. Inspect for air leaks at the throttle body mounting area, the mass air flow (MAF) sensor and intake manifold sealing surfaces.
  7. Inspect the wiring harness for the following conditions: Poor connections Pinches Cuts
  8. Inspect for loose, damaged, unseated, or missing sensors/components.
  9. Inspect the terminals for corrosion and correct contact.

Symptoms Testing

Backfire, Cuts Out/Misses, Detonation/Spark Knock, Engine Control Module (ECM) Commanded Reduced Engine Power, Dieseling/Run-On, Hard Start, Hesitation/Sag/Stumble, Lack of Power/Sluggishness/Sponginess, Poor Fuel Economy, Rough, Unstable, or Incorrect Idle and Stalling, or Surges/Chuggles

  1. Test for the following conditions: Incorrectly operating fuel system. Inspect for the following: Incorrect fuel pressure-Refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) Fuel injectors that are leaking or incorrectly operating-Refer to «Fuel Injector Diagnosis (CH47976)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) , «Fuel Injector Diagnosis (J39021 or Tech 2)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Contaminated or a poor fuel quality condition-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Incorrectly operating ignition system. Inspect for the following: Spark plugs with incorrect heat range or an abnormal condition-Refer to «Spark Plug Inspection»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__spark-plug-inspection) . Coolant or oil fouled spark plugs. For diagnosis, refer to «Loss of Coolant»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) , or «Symptoms - Engine Mechanical»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) . Secondary ignition system susceptible to moisture. Engine running, wet down the secondary ignition system with water from a spray bottle to help locate damaged or deteriorated components. Look/listen for arcing or misfiring as the water is applied. Weak spark using the J 26792 spark tester -Refer to «Electronic Ignition System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Incorrectly operating transmission torque converter clutch (TCC)-The scan tool should indicate an engine speed drop when the TCC is commanded ON. Refer to «Torque Converter Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/automatic-trans/#automatic-transmission-4l60-e-m30-diagnostic-information-and-procedures__torque-converter-diagnosis) Incorrectly operating A/C compressor Items that can cause an engine to run rich or lean. Refer to «DTC P0171, P0172, P0174, or P0175»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) for additional information. Slow responding heated oxygen sensors (HO2S). The heated oxygen sensors should respond quickly to different throttle positions. CAUTION: Refer to «Heated Oxygen and Oxygen Sensor Caution»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#dangers-warnings-and-cautions__heated-oxygen-and-oxygen-sensor-caution) . Water intrusion in the heated oxygen sensors connectors NOTE: The embossed arrows on the mass air flow (MAF) sensor indicate the direction of the intake air flow. The arrows must point toward the engine. Incorrect mass air flow sensor installation. A mass air flow sensor that is incorrectly installed may cause a hard start. Install the mass air flow in the proper direction. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions) . Incorrect mass air flow (MAF) sensor connections. Engine oil contaminated by fuel Engine mechanical failures. Inspect for the following and refer to «Symptoms - Engine Mechanical»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) : Excessive oil in the combustion chamber or leaking valve seals Incorrect cylinder compression Sticking or leaking valves Worn camshaft lobes Incorrect valve timing Worn rocker arms Broken valve springs Excessive carbon buildup in the combustion chambers-Clean the chambers with top engine cleaner, if necessary. Follow the instructions on the can. Incorrect engine parts Split or kinked vacuum hoses-Verify that the routing and connections are as shown on the Vehicle Emission Control Information label. Excessive knock sensor (KS) system spark retard activity Deteriorated or damaged exhaust system. Inspect the exhaust components for the following: Physical damage or possible internal failure Restricted three-way catalytic converter For more information, refer to «Symptoms - Engine Exhaust»(/chevrolet/express-g3500/2013-2013/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) . Electromagnetic interference (EMI) on the reference circuit, which can cause a misfire condition. You can usually detect electromagnetic interference with a scan tool by monitoring the engine speed parameter. A sudden increase in the engine speed parameter with little change in actual engine speed indicates that electromagnetic interference is present. Inspect the high voltage components near the ignition control circuit if a condition exists. Incorrectly operating crankcase ventilation valve-Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) . Stuck open evaporative emission (EVAP) canister purge solenoid Incorrectly operating engine cooling system. Inspect for the following conditions: The thermostat is the correct heat range. Refer to «Thermostat Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system__thermostat-diagnosis) . Proper engine coolant level-Refer to «Cooling System Draining and Filling (Vac N Fill)»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-vac) , «Cooling System Draining and Filling (Static Fill Diesel)»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. If the above conditions do not address the symptom, refer to the additional symptoms tests.

Additional Symptoms Tests

Detonation/Spark Knock

  1. Test for an engine overheating condition. Refer to «Engine Overheating»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system__engine-overheating) .
  2. Verify that the engine coolant temperature (ECT) sensor has not shifted in value. Allow the engine to run and reach operating temperature. Observe the ECT Sensor parameter with a scan tool and compare the reading to that parameter listed on the «K20 Engine Control Module: Scan Tool Information (LGH)»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-scan-tool-information__k20-engine-control-module-scan-tool) , list. If the reading is not in the range specified in the list, test the resistance of the engine coolant temperature sensor. Refer to «Temperature Versus Resistance»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-specifications__temperature-versus-resistance) , for resistance specifications. Replace the engine coolant temperature sensor if the resistance is not within specification. Refer to «Engine Coolant Temperature Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions) . If the engine coolant temperature sensor is within the specification, test the sensor circuits for high resistance.
  3. Inspect for excessive carbon buildup in the combustion chambers. Clean the chambers with Top Engine Cleaner, if necessary. Follow the instructions on the can.
  4. If there are no engine mechanical faults, fill the fuel tank with a known high quality fuel that meets the vehicle minimum octane requirements.

ECM Commanded Reduced Engine Power

Under certain conditions the ECM may limit engine power by reducing engine torque and, for some vehicles, fuel pressure as well. For most, but not all of the conditions, the ECM will illuminate the reduced engine power lamp on the instrument panel cluster, however a DTC may not be set. Observe the scan tool Reduced Engine Power History parameter or refer to K20 Engine Control Module: Scan Tool Information (LGH) to help determine the reason for the reduced engine power event.

Verify or inspect for the following

  1. Vehicle being operated at sustained high engine speeds, or, towing heavy loads up an incline for an extended period of time, which may cause the engine oil or coolant to overheat. A repair may not be necessary. Inspect the airflow passageways in front of the engine for obstructions and clear away any debris or foreign material that is found. If no obstructions are found, review approved driving habits with the customer. The customer may need to operate the vehicle at a higher engine speed to improve cooling system performance, or, at a slower engine speed to reduce engine load.
  2. A cooling fan condition which may cause the ECM to reduce engine power. Refer to «Cooling Fan Description and Operation (w/LGH)»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system) , and «Cooling System Description and Operation»(/chevrolet/express-g3500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system) to verify correct operation of the cooling fan.
  3. Reduced engine power due to OnStar® remote command. A repair may not be necessary. Verify the vehicle is not in the OnStar® initiated Stolen Vehicle Slowdown mode. Refer to «OnStar Stolen Vehicle Slowdown Active»(/chevrolet/express-g3500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system) , and «Remote Vehicle Speed Limiting Description and Operation»(/chevrolet/express-g3500/2013-2013/remont/door-locks-anti-theft-systems/#immobilizer-system__remote-vehicle-speed-limiting-description-and) for additional information.
  4. Excessively high fuel pressure condition. Refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) , and «Fuel System Description»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-description-and-operation) to verify fuel system operation.
  5. Maximum recommended engine oil life exceeded. Refer to the Owners Manual for scheduled maintenance recommendations.
  6. If equipped with automatic transmission, an incorrect learned brake pedal position (BPP) sensor. Verify the following do not exist: An engine control module has been replaced A BPP sensor that has been replaced An incorrect BPP sensor alignment or installation If any of the above occurred, the Brake Pedal Position Learn procedure must be performed.

Fuel Odor

  1. Inspect for a saturated EVAP canister-Refer to «Evaporative Emission Control System Description»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-description-and-operation) .
  2. Inspect for damaged, deteriorated, or leaking fuel lines and fuel system components.
  3. Inspect for a condition with the internal components of the fuel tank assembly-Refer to «Fuel System Description»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-description-and-operation) .

Hard Start

  1. Test the engine coolant temperature (ECT) sensor. Compare the ECT sensor value to the intake air temperature (IAT) sensor value on a cold engine. The ECT and IAT sensor values should be within ± 3°C (5°F). If the ECT sensor is out of range with the IAT sensor, test the resistance of the ECT sensor. Refer to «Temperature Versus Resistance»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-specifications__temperature-versus-resistance) , for resistance specifications. Replace the ECT sensor if the resistance is not within specification. Refer to «Engine Coolant Temperature Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions) . If the sensor is within the specification, test the ECT circuits for a high resistance.
  2. Test the idle air control (IAC) system.
  3. Test the fuel pump relay operation. The fuel pump should turn ON for 2 seconds when the ignition is turned ON. Refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  4. Observe the TB Idle Airflow Compensation parameter with a scan tool. A value greater than 90% may indicate an excessive accumulation of deposits in the throttle bore. Inspect the throttle body and clean, if necessary. Refer to «Throttle Body Cleaning»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__throttle-body-cleaning) .

Hesitation, Sag, Stumble

  1. Test the manifold absolute pressure (MAP) sensor. Refer to «DTC P0106»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p0010-to-dtc-p0507) .
  2. Test the generator. Refer to «Symptoms - Engine Electrical»(/chevrolet/express-g3500/2013-2013/remont/charging-system/#battery-charging-system-and-starting-system__symptoms-engine-electrical) . Repair the charging system if the generator output voltage is less than 9 volts or more than 16 volts.
  3. Test the fuel system for incorrect pressure or operation. Refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .

Lack of Power, Sluggishness, or Sponginess

  1. Inspect the engine electrical system for correct operation. Refer to «Symptoms - Engine Electrical»(/chevrolet/express-g3500/2013-2013/remont/charging-system/#battery-charging-system-and-starting-system__symptoms-engine-electrical) .
  2. Verify that each injector harness is connected to the correct injector.
  3. Inspect the mass air flow (MAF) sensor for obstruction, contamination, and damage. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions) .

Poor Fuel Economy

  1. Inspect for heavy loads being carried or towed
  2. Inspect for acceleration rate too much or too often
  3. Inspect for incorrect operation of the speedometer.
  4. Observe the TB Idle Airflow Compensation parameter with a scan tool. A value greater than 90% may indicate an excessive accumulation of deposits in the throttle bore. Inspect the throttle body and clean, if necessary. Refer to «Throttle Body Cleaning»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__throttle-body-cleaning) .
  5. Verify that the engine coolant temperature (ECT) has not shifted in value. Allow the engine to run and reach operating temperature. Observe the ECT Sensor parameter with a scan tool and compare the reading to that parameter listed on the «K20 Engine Control Module: Scan Tool Information (LGH)»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-scan-tool-information__k20-engine-control-module-scan-tool) , list. If the reading is not in the range specified in the list, test the resistance of the ECT sensor. Refer to «Temperature Versus Resistance»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-specifications__temperature-versus-resistance) , for resistance specifications. Replace the ECT sensor if the resistance is not within specification. Refer to «Engine Coolant Temperature Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions) . If the sensor is within the specification, test the ECT sensor circuits for high resistance.
  6. Inspect the mass air flow (MAF) sensor for obstruction, contamination, and damage. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions) .
  7. Inspect the brake system for brake drag.

Rough, Unstable, or Incorrect Idle and Stalling

  1. Observe the Throttle Body Idle Airflow Compensation parameter with a scan tool. A value greater than 90% may indicate an excessive accumulation of deposits in the throttle bore. Inspect the throttle body and clean, if necessary. Refer to «Throttle Body Cleaning»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__throttle-body-cleaning) .
  2. Inspect the engine mounts. Refer to «Engine Mount Inspection»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3__engine-mount-inspection) .

Surges/Chuggles

  1. Inspect for slow responding heated oxygen sensors (HO2S). The heated oxygen sensors should respond quickly to a change in throttle position. If the heated oxygen sensors do not respond to different throttle positions, inspect for contamination from fuel, silicon, or the incorrect use of RTV sealant. The sensors may have a white powdery coating and result in a high, but false, signal voltage, which gives a rich exhaust indication. The PCM reduces the amount of fuel delivered to the engine, causing a driveability condition.
  2. Verify that each injector harness is connected to the correct injector.

Poor Fuel Fill Quality

ProblemCauses
DEFINITION: During the fueling process a continual, occasional, or no-fuel nozzle shut-off condition has occurred.
Difficult to fillFuel fill limiter vent valve stuck closed Evaporative emission (EVAP) canister restricted EVAP vent valve stuck closed Hose between canister and canister vent solenoid twisted or kinked if applicable High fuel temperature Fuel filler hose is kinked Faulty dispensing nozzle Ignition switch ON, vent valve closed
Over fillFill limiter vent valve stuck open or leaking Fuel inlet check valve stuck open
Pre-mature shut-off of the fuel dispensing nozzle occurs immediately after engaging dispensing nozzle, tank emptyRestricted vapor lines or fuel fill pipe High fuel temperature Inlet check valve at tank stuck closed, fill pipe full of fuel Fuel tank full, gauge not accurate
Pre-mature shut-off of the fuel dispensing nozzle, more than 1/8 of tank capacity dispensedKinked, pinched or plugged lines in fuel tank vent system EVAP vent valve stuck closed or restricted EVAP canister restricted Fuel limiting vent valve stuck closed or obstruction at top of fuel tank
Fuel SpitbackRestricted EVAP canister High fuel temperature Ignition switch ON, EVAP vent valve closed

Poor Fuel Fill Quality

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The malfunction indicator lamp (MIL) illuminates to inform the driver that an emission system failure has occurred and the engine control system requires service. Ignition voltage is supplied directly to the MIL. The engine control module (ECM) turns the MIL ON by grounding the MIL control circuit when the emission system fault occurs. Under normal operating conditions, the MIL should be ON only when the ignition is ON and the engine is OFF.

If the condition is intermittent, move the related harnesses and connectors while monitoring the scan tool MIL control circuit status parameters. Perform this test with the ignition ON and the engine OFF, and with the engine running. The MIL control circuit status parameters will change from OK or Not Run to Malfunction if there is a condition with the circuit or a connection.

Schematic Reference

  1. «Instrument Cluster Schematics»(/chevrolet/express-g3500/2013-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)
  2. «Engine Controls Schematics»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-wiring-schematic-diagrams)

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, command the malfunction indicator lamp ON and OFF with a scan tool.
  2. Verify that the malfunction indicator lamp turns ON and OFF as commanded. If the malfunction indicator lamp does not turn ON and OFF as commanded Refer to Circuit/System Testing. If the malfunction indicator lamp turns ON and OFF as commanded
  3. Ignition ON, command the malfunction indicator lamp ON and OFF with a scan tool.
  4. Verify that the control circuit status parameters listed below display OK or Not Run The MIL Control Circuit Low Voltage Test Status The MIL Control Circuit Open Test Status The MIL Control Circuit High Voltage Test Status If Malfunction is displayed Refer to Circuit/System Testing. If OK or Not Run is displayed
  5. Engine running, command the malfunction indicator lamp ON and OFF with a scan tool.
  6. Verify that the control circuit status parameters listed below display OK or Not Run The MIL Control Circuit Low Voltage Test Status The MIL Control Circuit Open Test Status The MIL Control Circuit High Voltage Test Status If Malfunction is displayed Refer to Circuit/System Testing. If OK or Not Run is displayed
  7. All OK.
  1. Ignition OFF.
  2. Disconnect the X1 harness connector at the K20 Engine Control Module.
  3. Ignition ON, verify the malfunction indicator lamp does not illuminate. If the malfunction indicator lamp illuminates Test for infinite resistance between the malfunction indicator lamp control circuit terminal X1 27 and ground. If less than infinite resistance, repair the short to ground in the circuit. If resistance is infinite, replace the P16 instrument cluster. If the malfunction indicator lamp does not illuminate
  4. Connect a 3 A fused jumper wire between the malfunction indicator lamp control circuit terminal X1 27 and ground.
  5. Verify the malfunction indicator lamp illuminates. If the malfunction indicator lamp does not illuminate Test the malfunction indicator lamp control circuit terminal X1 27 for a short to voltage or an open/high resistance. If the malfunction indicator lamp control circuit terminal X1 27 is shorted to voltage or has an open/high resistance, repair as necessary. If the malfunction indicator lamp control circuit terminal X1 27 tests normal Test the instrument cluster ignition voltage circuit for a short to ground or an open/high resistance. If the instrument cluster ignition voltage circuit is shorted to ground or has an open/high resistance, repair as necessary. If the instrument cluster ignition voltage circuit tests normal, replace the P16 instrument panel cluster/bulb. If the malfunction indicator lamp illuminates
  6. Replace the K20 Engine Control Module.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup.
  2. «Instrument Cluster Replacement»(/chevrolet/express-g3500/2013-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

This Engine Cranks but Does Not Run diagnostic is an organized approach to identify a condition which causes the engine to crank but does not continue to run. This diagnostic directs the service technician to the appropriate system diagnosis. This diagnostic assumes the vehicle system voltage levels are adequate for starter motor operation. Refer to Battery Inspection/Test , and Engine Cranks Slowly . The fuel level supply must be adequate, and the fuel quality must be able to sustain the combustion process.

  1. When disconnecting electrical connectors or removing fuses and relays from a fuse block, always inspect both mating electrical terminals for corrosion and terminal tightness.
  2. Use the J 35616 connector test adapter kit for any test that requires probing the underhood fuse block terminals, component wire harness terminals, or the ECM wire harness terminals.

Schematic Reference

Connector End View Reference

  1. «COMPONENT CONNECTOR END VIEWS - INDEX»(/chevrolet/express-g3500/2013-2013/remont/body-electrical/#wiring-systems-and-power-management-component-connector-end-views-index)
  2. «Electrical Center Identification Views»(/chevrolet/express-g3500/2013-2013/remont/electrical-component-locations/#wiring-systems-and-power-management-component-locator-electrical-center-identification-views)

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Special Tools

  1. J 34730-1A Fuel Pressure Gauge
  2. J 35616 Connector Test Adapter Kit

Attempt to start the engine. The engine should start and run.

  1. If the vehicle passes the Circuit/System Verification test, then refer to «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures) .
  1. Crank the engine while observing the scan tool Vehicle DTC Information. If any of the following DTCs are set, diagnose these first: DTC P0117, P0118, P0122, P0123, P0201-P0208, P0222, P0223, P0335, P0336, P0351-P0358, P0513, P0562, P0563, P0601-P0604, P0606, P0607, P062F, P0633, P0685, P0690, P1516, P1631, P1682, or P2610. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. With the ignition ON and the engine OFF, test the fuses that are supplied ignition 1 voltage by the powertrain relay. The test lamp should illuminate ON for each test point of the fuses. If the test lamp does not illuminate on, for at least one test point of each fuse, refer to «DTC P0685, P0689, P0690, or P1682»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  3. Crank the engine while observing the scan tool engine speed parameter. If engine RPM is not indicated, refer to «DTC P0335 or P0336»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  4. Install a spark plug tester onto one ignition module/coil assembly, on each bank of the engine.
  5. Crank the engine while observing both spark plug testers. Both spark plug testers should spark. If spark is not observed, is inconsistent, or weak on either spark plug tester, refer to «Electronic Ignition System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  6. With the ignition ON and the engine OFF, command the fuel pump ON and OFF with the scan tool. The fuel pump should energize when commanded ON, and de-energize when commanded OFF. If the fuel pump does not turn ON and OFF, refer to «Fuel System Diagnosis (Without FPCM)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (LC8\K07\UFP)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (LC8\FHZ)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (FPCM)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel System Diagnosis (LC8\K07\UFM)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  7. Turn OFF the ignition.
  8. Install the J 34730-1A fuel pressure gauge . With the ignition ON and the engine OFF, command the fuel pump ON several times with the scan tool. Refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) for the fuel pressure specification.
  9. Inspect for the following conditions: Skewed Engine Coolant Temperature (ECT) sensor. Compare the actual engine coolant temperature to the ECT parameter Restricted air filter and air intake system Contaminated fuel-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) . Spark plugs damaged, fouled or incorrect heat range-Refer to «Spark Plug Inspection»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__spark-plug-inspection) . Restricted exhaust system-Refer to «Restricted Exhaust»(/chevrolet/express-g3500/2013-2013/remont/exhaust/#engine-exhaust-system) . Engine mechanical conditions, such as worn timing chain, sprocket gears, low compression, etc-Refer to «Symptoms - Engine Mechanical»(/chevrolet/express-g3500/2013-2013/remont/mechanical/#engine-mechanical-43l-lu3) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The engine control module (ECM) enables the appropriate fuel injector pulse for each cylinder. The ignition voltage is supplied directly to the fuel injectors. The ECM controls each fuel injector by grounding the control circuit via a solid state device called a driver. A fuel injector coil winding resistance that is too high or too low will affect the engine driveability. A fuel injector control circuit DTC may not set, but a misfire may be apparent. The fuel injector coil windings are affected by temperature. The resistance of the fuel injector coil windings will increase as the temperature of the fuel injector increases.

When performing the fuel injector balance test, the scan tool is first used to energize the fuel pump relay. The fuel injector tester or the scan tool is then used to pulse each injector for a precise amount of time, allowing a measured amount of the fuel to be injected. This causes a drop in the system fuel pressure that can be recorded and used to compare each injector.

  1. Monitoring the misfire current counters, or misfire graph, may help to isolate the fuel injector that is causing the condition.
  2. Operating the vehicle over a wide temperature range may help isolate the fuel injector that is causing the condition.
  3. Perform the fuel injector coil test within the conditions of the customer's concern. A fuel injector condition may only be apparent at a certain temperature, or under certain conditions.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

  1. CH-48027 Digital Pressure Gauge
  2. J 39021 Fuel Injector Coil and Balance Tester
  3. J 39021-210 Injector Tester Adapter Box
  4. J 39021-301 V-6 Fuel Injector Test Adapter
  5. J 44602 Injector Test Adapter

Fuel Injector Coil Test

Verify the resistance of each fuel injector with one of the following methods

  1. If the engine coolant temperature (ECT) sensor is between 10-32°C (50-90°F), the resistance of each fuel injector should be 11-14 ohms. If the injectors measure OK, perform the Fuel Injector Balance Test - Fuel Pressure Test. If not within the specified range, replace the fuel injector.
  2. If the ECT sensor is not between 10-32°C (50-90°F), measure and record the resistance of each fuel injector with a DMM. Subtract the lowest resistance value from the highest resistance value. The difference between the lowest value and the highest value should be equal to or less than 3 ohms. If the difference is equal to or less than 3 ohms, refer to Fuel Injector Balance Test - Fuel Pressure Test for further diagnosis of the fuel injectors. If the difference is more than 3 ohms, add all of the fuel injector resistance values to obtain a total resistance value. Divide the total resistance value by the number of fuel injectors to obtain an average resistance value. Subtract the lowest individual fuel injector resistance value from the average resistance value. Compute the difference between the highest individual fuel injector resistance value and the average resistance value. Replace the fuel injector that displays the greatest difference above or below the average.
IMPORTANTDO NOT perform this test if the engine coolant temperature (ECT) is above 94°C (201°F). Irregular fuel pressure readings may result due to hot soak fuel boiling. Verify that adequate fuel is in the fuel tank before proceeding with this diagnostic. Before proceeding with this test review the User Manual CH 48027-5 for Safety Information and Instructions.

Fuel Injector Balance Test-Fuel Pressure Test

  1. Install a CH-48027 digital pressure gauge . Refer to «Fuel Pressure Gauge Installation and Removal»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions) .
  2. Turn ON the ignition, with the engine OFF.
  3. Command the fuel pump relay ON with a scan tool.
  4. Observe the fuel pressure gauge with the fuel pump commanded ON. The fuel pressure should be 345-414 kPa (50-60 psi). If the fuel pressure is not 345-414 kPa (50-60 psi), refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  5. Monitor the CH-48027 digital pressure gauge for one minute. The fuel pressure should not decrease more than 34 kPa (5 psi). If the fuel pressure decreases more than 34 kPa (5 psi), refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  6. Perform the Fuel Injector Balance Test with Special Tool or the Fuel Injector Balance Test with Tech 2.

Fuel Injector Balance Test with Special Tool

  1. Set the amperage supply selector switch on the fuel injector tester to the Balance Test 0.5-2.5 amp position.
  2. Connect the J 39021 fuel injector coil and balance tester , J 39021-210 injector tester adapter box , and the J 39021-301 V-6 fuel injector test adapter to the fuel meter body.
  3. Command the fuel pump relay ON and then OFF three times with a scan tool. On the last command, as the fuel pressure begins to slowly degrade and stabilize, select a fuel pressure within 34 kPa (5 psi) of the maximum pump pressure. Record this fuel pressure. This is the starting pressure at which you will pulse each injector.
  4. Command the fuel pump relay ON one more time and energize the fuel injector by depressing the Push to Start Test button on the J 39021 fuel injector coil and balance tester at the previously selected pressure.
  5. After the injector stops pulsing, select Min from the Display Mode and record the Min pressure.
  6. Clear the Min/Max results.
  7. Select Normal from the Display Mode.
  8. Repeat steps 2 and 4 through 7 for each fuel injector.
  9. Perform the Pressure Drop Calculation.

Fuel Injector Balance Test with Tech 2

  1. Command the fuel pump relay ON and then OFF three times with a scan tool. On the last command, as the fuel pressure begins to slowly degrade and stabilize, select a fuel pressure within 34 kPa (5 psi) of the maximum pump pressure. Record this fuel pressure. This is the starting pressure at which you will pulse each injector.
  2. With a scan tool, select the Fuel Injector Balance Test function within the Special Functions menu.
  3. Select an injector to be tested.
  4. Press Enter to prime the fuel system.
  5. Energize the fuel injector by depressing the Pulse Injector button on the scan tool at the previously selected pressure.
  6. After the injector stops pulsing, select Min from the Display Mode on the CH-48027 digital pressure gauge and record the Min pressure.
  7. Clear the Min/Max results on the CH-48027 digital pressure gauge .
  8. Select Normal from the Display Mode on the CH-48027 digital pressure gauge.
  9. Press Enter on the scan tool to bring you back to the Select Injector screen.
  10. Repeat steps 3 through 9 for each fuel injector.
  11. Perform the Pressure Drop Calculation.

Pressure Drop Calculation

  1. Subtract the minimum pressure from the starting pressure for one fuel injector. The result is the pressure drop value.
  2. Obtain a pressure drop value for each fuel injector.
  3. Add all of the individual pressure drop values except for the injector suspected of being faulty. This is the total pressure drop.
  4. Divide the total pressure drop by the number of fuel injectors that were added together. This is the average pressure drop. The difference between any individual pressure drop and the average pressure drop should not be more than 20 kPa (3 psi). If the difference between any individual pressure drop and the average pressure drop is more than 20 kPa (3 psi), replace the fuel injector, E-85 only. All other engine, refer to «Fuel Injector Cleaning»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__fuel-injector-cleaning) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The engine control module (ECM) enables the appropriate fuel injector pulse for each cylinder. The ignition voltage is supplied directly to the fuel injectors. The ECM controls each fuel injector by grounding the control circuit via a solid state device called a driver. A fuel injector coil winding resistance that is too high or too low will affect the engine driveability. A fuel injector control circuit DTC may not set, but a misfire may be apparent. The fuel injector coil windings are affected by temperature. The resistance of the fuel injector coil windings will increase as the temperature of the fuel injector increases.

The CH-47976 active fuel injector tester , is used to test the fuel pump, fuel system leak down, and the fuel injectors. Following the User Guide, CH 47976-11, and the on screen prompts or selections, will indicate the steps required to perform each of the available tests. The tester will perform all of the tests automatically and display results of the test. The results can also be down loaded for storage and printing.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Special Tools

CH-47976 Active Fuel Injector Tester

Fuel Injector Coil Test

Verify the resistance of each fuel injector with one of the following methods

  1. If the engine coolant temperature (ECT) sensor is between 10-32°C (50-90°F), the resistance of each fuel injector should be 11-14 ohms. If the injectors measure OK, perform the Active Fuel Injector Tester (AFIT) Test Procedure. If not within the specified range, replace the fuel injector.
  2. If the ECT sensor is not between 10-32°C (50-90°F), measure and record the resistance of each fuel injector with a DMM. Subtract the lowest resistance value from the highest resistance value. The difference between the lowest value and the highest value should be equal to or less than 3 ohms. If the difference is equal to or less than 3 ohms, refer to AFIT Test Procedure. If the difference is more than 3 ohms, add all of the fuel injector resistance values to obtain a total resistance value. Divide the total resistance value by the number of fuel injectors to obtain an average resistance value. Subtract the lowest individual fuel injector resistance value from the average resistance value. Compute the difference between the highest individual fuel injector resistance value and the average resistance value. Replace the fuel injector that displays the greatest difference above or below the average.
IMPORTANTDO NOT perform this test if the engine coolant temperature (ECT) is above 94°C (201°F). Irregular fuel pressure readings may result due to hot soak fuel boiling. Verify that adequate fuel is in the fuel tank before proceeding with this diagnostic.

AFIT Test Procedure

  1. Turn OFF all accessories.
  2. Turn OFF the ignition.
  3. Install the AFIT. Refer to the AFIT User Guide.
  4. Turn ON the AFIT and select the vehicle.
  5. Turn ON the ignition and perform the Injector Test. If the AFIT aborts testing due to fuel pressure or fuel leak down, refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  6. View the test results. If any injector exceeds the recommended tolerance, replace the injector(s), E-85 only. All other engine, refer to «Fuel Injector Cleaning»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__fuel-injector-cleaning) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Battery Voltage - Relay Switch Side12
Fuel Pump Supply Voltage123
Fuel Pump Relay ControlP0230P0230P0230
Fuel Pump Relay GroundP0230
Fuel Pump Ground2
1 Open fuel pump fuse, cranks no start 2 Cranks no start 3 Fuel pump operates continuously, then discharged battery

The engine control module (ECM) enables the fuel pump relay when the ignition switch is turned ON. The ECM will disable the fuel pump relay within 2 seconds unless the ECM detects ignition reference pulses. The ECM continues to enable the fuel pump relay as long as ignition reference pulses are detected. The ECM disables the fuel pump relay within 2 seconds if ignition reference pulses cease to be detected and the ignition remains ON.

The following conditions may cause the fuel pump fuse to open

  1. The fuse is faulty.
  2. There is an intermittent short to ground in the supply voltage circuit of the fuel pump.
  3. The fuel pump has an intermittent internal condition.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 43244 Relay Puller Pliers

IMPORTANTAn open or a short to voltage in the control circuit will cause both the Ckt. Open Test Status and the Ckt. Short Volts Test Status parameters to display Fault.

Ignition ON, command the fuel pump relay ON and OFF with a scan tool while observing the following control circuit status parameters

  1. Fuel Pump Relay Ckt. Short Gnd Test Status
  2. Fuel Pump Relay Ckt. Open Test Status
  3. Fuel Pump Relay Ckt. Short Volts Test Status

Each parameter should toggle between OK and Not Run or Not Run and OK.

  1. Ignition OFF, disconnect the fuel pump relay.
  2. Ignition ON, verify that a test lamp illuminates between the ground circuit terminal and B+. If the test lamp does not illuminate, test the ground circuit for a short to voltage or an open/high resistance.
  3. Verify that a test lamp does not illuminate between the ground circuit terminal and the control circuit terminal. If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  4. Remove the test lamp.
  5. Command the fuel pump relay ON with a scan tool. Verify the scan tool fuel pump relay Ckt. Short Grnd Test Status parameter is OK. If not the specified value, test the fuel pump relay control circuit for a short to ground. If the circuit tests normal, replace the ECM.
  6. Install a 3A fused jumper wire between the fuel pump relay control circuit terminal and the ground circuit terminal. Command the fuel pump ON with a scan tool. Verify the scan tool fuel pump relay Ckt. Short Grnd Test Status parameter is Fault. If not the specified value, test the fuel pump relay control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  7. Inspect the fuel pump fuse. If the fuel pump fuse is open, test for the following conditions: A short to ground in the relay switch B+ circuit A short to ground in the supply voltage circuit of the fuel pump If the above circuits test normal, replace the fuel tank module.
  8. Verify that a test light illuminates between the B+ circuit and ground. If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.
  9. Connect a 15 A fused jumper wire between the B+ circuit and the supply voltage circuit of the fuel pump. Verify the fuel pup is activated. If the fuel pump does not activate, test for the following conditions: An open/high resistance in the supply voltage circuit of the fuel pump An open/high resistance in the ground circuit of the fuel pump If the above circuits test normal, replace the fuel tank module.
  10. If all circuits test normal, test or replace the fuel pump relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Fuel Tank Fuel Pump Module Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__fuel-tank-fuel-pump-module-replacement)
  2. «Relay Replacement (Within an Electrical Center)»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) , «Relay Replacement (Attached to Wire Harness)»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
  3. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) enables the fuel pump relay when the ignition switch is turned ON. The ECM will disable the fuel pump relay within 2 seconds unless the ECM detects ignition reference pulses. The ECM continues to enable the fuel pump relay as long as ignition reference pulses are detected. The ECM disables the fuel pump relay within 2 seconds if ignition reference pulses cease to be detected and the ignition remains ON.

The fuel system is a returnless on-demand design. The fuel pressure regulator is a part of the fuel pump module, eliminating the need for a return pipe from the engine. A returnless fuel system reduces the internal temperature of the fuel tank by not returning hot fuel from the engine to the fuel tank. Reducing the internal temperature of the fuel tank results in lower evaporative emissions.

The fuel tank stores the fuel supply. An electric turbine style fuel pump attaches to the fuel pump module inside the fuel tank. The fuel pump supplies high pressure fuel through the fuel filter and the fuel feed pipe to the fuel injection system. The fuel pump provides fuel at a higher rate of flow than is needed by the fuel injection system. The fuel pump also supplies fuel to a venturi pump located on the bottom of the fuel pump module. The function of the venturi pump is to fill the fuel pump module reservoir. The fuel pressure regulator, a part of the fuel pump module, maintains the correct fuel pressure to the fuel injection system. The fuel pump module contains a reverse flow check valve. The check valve and the fuel pressure regulator maintain fuel pressure in the fuel feed pipe and the fuel rail in order to prevent long cranking times.

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Special Tools

  1. CH-48027 Digital Pressure Gauge
  2. J 37287 Fuel Line Shut-off Adapter
IMPORTANTInspect the fuel system for damage or external leaks before proceeding. Verify that adequate fuel is in the fuel tank before proceeding. The fuel pump relay may need to be commanded ON a few times in order to obtain the highest possible fuel pressure. Before proceeding with this test review the User Manual CH 48027-5 for Safety Information and Instructions.
  1. Ignition ON, engine OFF, command the fuel pump relay ON with a scan tool. You should hear the fuel pump turn ON and OFF. If the fuel pump does not operate, refer to «Fuel System Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  2. Ignition OFF, all accessories OFF, install a CH-48027 digital pressure gauge. Refer to «Fuel Pressure Gauge Installation and Removal»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions) .
  3. Ignition ON, engine OFF, command the fuel pump relay ON with a scan tool. Verify the fuel pressure is between 345-414 kPa (50-60 psi) and does not decrease more than 34 kPa (5 psi) in 1 minute.
  1. Ignition ON, engine OFF, command the fuel pump relay ON with a scan tool and observe the fuel pressure gauge while the fuel pump is operating. Verify the fuel pressure is between 345-414 kPa (50-60 psi). If the fuel pressure is greater than the specified range, replace the fuel pump module. If the fuel pressure is less than the specified range, test, inspect, and repair the items listed below. If all items test normal, replace the fuel pump module. Restricted fuel feed pipe Inspect the harness connectors and the ground circuits of the fuel pump for poor connections.
  2. Verify that the fuel pressure does not decrease more than 34 kPa (5 psi) in 1 minute. If the fuel pressure decreases more than the specified value, perform the following procedure: Ignition OFF, relieve the fuel pressure. Refer to «Fuel Pressure Relief (CH-48027)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-repair-instructions__fuel-pressure-relief-ch-48027) , «Fuel Pressure Relief (Without CH-48027)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-repair-instructions__fuel-pressure-relief-without-ch-48027) . Install the J 37287 fuel line shut-off adapter between the fuel feed pipe and the fuel rail. Open the valve on the J 37287 fuel line shut-off adapter. Ignition ON, command the fuel pump relay ON with a scan tool and bleed the air from the CH-48027 digital pressure gauge . Command the fuel pump relay ON and then OFF with a scan tool. Close the valve on the J 37287 fuel line shut-off adapter. Monitor the fuel pressure for 1 minute. If the fuel pressure decreases more than 34 kPa (5 psi) within the specified time, locate and replace the leaking fuel injector(s). If the fuel pressure does not decrease more than 34 kPa (5 psi) within the specified time, replace the fuel pump module.
  3. Relieve the fuel pressure to 69 kPa (10 psi). Verify that the fuel pressure does not decrease more than 14 kPa (2 psi) in 5 minutes. If the fuel pressure decreases more than the specified value, replace the fuel pump module.
  4. Operate the vehicle within the conditions of the customer's concern while monitoring the fuel pressure with the CH-48027 digital pressure gauge . The fuel pressure should not drop off during acceleration, cruise or hard cornering. If the fuel pressure drops off, test, inspect, and repair the items listed below. If all items test normal, replace the fuel pump module. Restricted fuel feed pipe Inspect the harness connectors and the ground circuits of the fuel pump for poor connections
  5. If the fuel system tests normal, refer to «Symptoms - Engine Controls»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Fuel Hose/Pipe Assembly Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Fuel Injector Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  3. «Fuel Tank Fuel Pump Module Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__fuel-tank-fuel-pump-module-replacement)
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Test Description

Water contamination in the fuel system may cause driveability conditions such as hesitation, stalling, no start, or misfires in one or more cylinders. Water may collect near a single fuel injector at the lowest point in the fuel injection system and cause a misfire in that cylinder. If the fuel system is contaminated with water, inspect the fuel system components for rust or deterioration.

Ethanol concentrations of greater than 10 percent in nonblended gasoline, or greater than 85 percent with E85 blended gasoline for flexible fuel applications can cause driveability conditions such as hesitation, lack of power, stalling, or no start. Excessive concentrations of ethanol used in vehicles not designed for it may cause fuel system corrosion, deterioration of rubber components, and fuel filter restriction.

Special Tools

J 44175 Fuel Composition Tester

System Verification

The fuel sample should be drawn from the bottom of the tank so that any water present in the tank will be detected. The sample should be bright and clear.

  1. If the sample appears cloudy, or contaminated with water, as indicated by a water layer at the bottom of the sample, perform the Particulate Contaminants in Fuel Testing Procedure.
  2. If alcohol contamination is suspected, perform the Alcohol in Fuel Testing procedure.

Alcohol in Fuel Testing with Special Tool

  1. Test the fuel composition using J 44175 fuel composition tester and Instruction Manual.
  2. If water appears in the fuel sample, clean the fuel system.
  3. Subtract 50 from the reading on the DMM in order to obtain the percentage of alcohol in the fuel sample.
  4. If the nonblended gasoline fuel sample measures more than 15 percent ethanol, or if the E85 blended gasoline fuel sample measures more than 91 percent ethanol, add fresh regular gasoline to the vehicles's fuel tank.
  5. Test the fuel composition.
  6. If additional testing indicates that the ethanol percentage is still above 15 percent for a nonblended gasoline sample, drain and replace the vehicle's fuel. Refer to «Fuel Tank Draining (L59)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__fuel-tank-draining-l59) , «Fuel Tank Draining (Without L59)»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions__fuel-tank-draining-without-l59) . If additional testing indicates that the E85 blended gasoline sample still measures above 91 percent, continue adding fresh, regular gasoline until the ethanol content is 85 percent or less.

Alcohol in Fuel Testing without Special Tool

  1. Using a 100 ml (3.38 oz) specified cylinder with 1 ml (0.034 oz) graduation marks, fill the cylinder with fuel to the 90 ml (3.04 oz) mark.
  2. Add 10 ml (0.34 oz) of water in order to bring the total fluid volume to 100 ml (3.38 oz) and install a stopper.
  3. Shake the cylinder vigorously for 10-15 seconds.
  4. Carefully loosen the stopper in order to release the pressure.
  5. Re-install the stopper and shake the cylinder vigorously again for 10-15 seconds.
  6. Put the cylinder on a level surface for approximately 5 minutes in order to allow adequate liquid separation. If alcohol is present in the fuel, the volume of the lower layer, which would now contain both alcohol and water, will be more than 10 ml (0.34 oz). For example, if the volume of the lower layer is increased to 15 ml (0.51 oz), this indicates at least 5 percent alcohol in the fuel. The actual amount of alcohol may be somewhat more because this procedure does not extract all of the alcohol from the fuel.

Particulate Contaminants in Fuel Testing Procedure

  1. Using an approved fuel container, draw approximately 0.5 liter (0.53 qt) of fuel.
  2. Place the container on a level surface for approximately 5 minutes in order to allow settling of the particulate contamination. Particulate contamination will show up in various shapes and colors. Sand will typically be identified by a white or light brown crystals. Rubber will appear as black and irregular particles.
  3. Observe the fuel sample. If any physical contaminants or water are present, clean the fuel system.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This ignition system uses an ignition control module. The engine control module (ECM) controls the spark events by transmitting the timing pulses on the ignition control (IC) circuits to the cylinder ignition coils in firing order sequence.

  1. An open/high resistance on the low reference circuit to the ignition coil may cause a misfire.
  2. An erratic or weak spark is considered a no spark condition.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
  4. «Wiring Repairs»(/chevrolet/express-g3500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Special Tools

EL 26792 HEI Spark Tester

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

Verify the following conditions. Refer to Spark Plug Wire Inspection , and Ignition System Specifications .

  1. The ignition coil and spark plug wires are correctly connected
  2. The spark plug wire resistance is within specifications
  3. The correct spark plug type
  4. The correct spark plug gap
  5. The correct spark plug torque
  1. If a condition was found Repair or replace as necessary.
  1. If a condition was not found Refer to Circuit/System Testing.

Note. Do not perform this diagnostic procedure unless you were sent here from a misfire DTC or the Engine Cranks But Does Not Run diagnostic.

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the Ignition Control Module. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 5 ohms between the ground circuit terminal E and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
  3. Test for less than 5 ohms between the low reference circuit terminal D and ground. If 5 ohms or greater Ignition OFF, disconnect the X2 harness connector at the Engine Control Module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the Engine Control Module. If less than 5 ohms
  4. Ignition ON.
  5. Verify a test lamp illuminates between the ignition circuit terminal F and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF, remove the test lamp. Test for less than 2 ohms in the ignition circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open NOTE: The ignition circuit may supply voltage to other components. Make sure to test all circuits and components for a short to ground that share the ignition circuit. Ignition OFF, remove the test lamp, and disconnect all components on the circuit. Test for infinite resistance between the ignition circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Replace the fuse, ignition ON. Verify the fuse is good after connecting each of the components one at a time. If the fuse opens, replace the component that opens the fuse when connected. If the fuse is good, all OK. If the test lamp illuminates
  6. Test or replace the Ignition Control Module.

Note. You must perform the Circuit/System Testing before proceeding with Component Testing.

  1. Ignition OFF, connect the EL 26792 HEI Spark Tester to each spark plug wire.
  2. Engine Running.
  3. Verify the spark output of the Ignition Control Module at each spark plug wire. If any have no output or the output is weak Replace the Ignition Control Module. If the output is good
  4. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Ignition Coil Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  2. «Spark Plug Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  3. «Spark Plug Wire Replacement»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-repair-instructions)
  4. «Control Module References»(/chevrolet/express-g3500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.

Evaporative Emission System Diagnosis

Special Tools

EN 41413-VLV EVAP Service Port Vent Fitting

Operating Instructions for the Evaporative Emission System Tester (EEST)

Vehicle Setup

  1. Engine OFF, open the hood. Position a large fan to blow air under the vehicle onto the fuel tank area.
  2. Connect the red battery clip from the tester to the positive battery terminal.
  3. Connect the black battery clip from the tester to chassis ground.

Flow Meter Test - Leak Detection

  1. Open the Nitrogen tank valve and turn the NITROGEN/SMOKE valve on the front control panel to NITROGEN.
  2. Connect the hose to the correct test orifice on the bottom front of the tester. For orifice size, refer to the vehicle specific information found in service procedures for DTCs that relate to evaporative emission (EVAP) system leaks.
  3. Press and release the remote switch to activate the tester.
  4. Position the sliding red flag on the flow meter to align with the floating indicator. When the red flag is set, press and release the remote switch to deactivate the tester.
  5. Remove the hose from the test orifice and install the hose onto the vehicle. For proper connection location, and the special tool numbers for any adapters that may be required, refer to the service procedures for DTCs that relate to EVAP system leaks.
  6. Ignition ON, seal the EVAP system per instructions in the service procedures for DTCs that relate to EVAP system leaks. Most systems can be sealed using a scan tool output control for the EVAP vent solenoid valve, other systems require that the vent system be plugged.
  7. Press and release the remote switch to activate the nitrogen flow and fill the system.
  8. Compare the stable floating indicator position to the red flag. Below the red flag, the result is acceptable, Pass. Test complete Above the red flag, the result is unacceptable, Fail. Go to the Smoke Procedure
  9. Press and release the remote switch to deactivate the tester.

Smoke Procedure - Locate the Leak

  1. Turn OFF any fans that may cause air movement around or near the vehicle.
  2. Connect the nitrogen/smoke hose to the vehicle as directed in the service procedures. Some vehicles require that the nitrogen/smoke hose be connected at the front of the EVAP system at the EVAP service port. An adapter may be necessary. Other vehicles require the connection be made at the rear of the system using an adapter at the fuel fill cap. Consult the service procedures for DTCs that relate to evaporative emission (EVAP) system leaks for vehicle specific instructions regarding connection location and adapters.
  3. Open the nitrogen tank valve and turn the nitrogen/smoke valve on the control panel to smoke.
  4. Press and release the remote switch to activate the tester and inject smoke into the EVAP system.
  5. Verify smoke has filled the EVAP system by opening the system opposite the end where smoke is injected. When injecting smoke at the service port, remove the fuel fill cap until smoke is observed. Then close the system and continue testing. If using a special tool fuel fill cap adapter at the filler neck, vent the system at the service port, with special tool EN 41413-VLV EVAP Service Port Vent Fitting, until smoke is observed then remove the vent fitting tool and close the system to continue with the test.
  6. Press and release the remote switch to deactivate the tester.
  7. Introduce smoke into the system for an additional 60 s. Continue introducing smoke at 15 s intervals, as necessary.
  8. Using a high-intensity white light, inspect the entire EVAP system path, and look for the source of the leak indicated by the exiting smoke. Introduce smoke at 15 s intervals, as needed, until leak source is identified.

Temperature Variation Instructions

The Concern

Ideal circumstances for conducting the EVAP flow meter test require equal temperatures between the nitrogen gas and the vehicle EVAP system. Significant differences in temperature between them can result in a flow or pressure change during testing, causing misleading results. Typically, the EEST is stored indoors, approximately 21°C (70°F). Vehicles brought in for diagnosis may have an EVAP system at significantly different temperatures.

For Example

Note. With no temperature difference between the nitrogen gas and EVAP system, the resulting vehicle EVAP system pressure will remain stable at 3.2 kPa, 13 in. H2O (0.5 PSI) once pressurized, providing no leaks are present.

When the EVAP flow meter tests are performed with significant differences in temperature between the nitrogen gas and the vehicle EVAP system, the following results can occur

  1. An increase in flow during the flow meter test can be caused by a vehicle's warm EVAP system cooling down.
  2. A decrease in flow during the flow meter test can be caused by a vehicle's cool EVAP system warming up.

The Solution

When working on a vehicle with significant temperature differences between the vehicle EVAP system and the nitrogen gas, allow the vehicle EVAP system temperature to stabilize as close as possible to the temperature of the nitrogen gas before conducting the Flow Meter Test.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Description

Several states require that a vehicle pass on-board diagnostic (OBD) system tests and the inspection/maintenance (I/M) emission inspection in order to renew license plates. This is accomplished by viewing the I/M System Status display on a scan tool. Using a scan tool, the technician can observe the I/M System Status in order to verify that the vehicle meets the criteria that complies with the local area requirements. While testing in the I/M System Status mode, some DTCs may occur that are called I/M Test DTCs. An I/M Test DTC is defined as a fault code that is currently commanding the MIL ON, and is stored in non-volatile memory. The intended use of this data is to prevent vehicles from passing I/M inspection without proper repair to the vehicle. These fault codes are not erasable from any scan tool command or erasable by disconnecting power to the controller. The I/M Test DTCs will be supported by all emissions related ECUs such as ECMs, TCMs, FPCMs, etc. An I/M Test DTC will not be stored or erased from the ECU except at the end of trip processing which occurs 5 s after ignition OFF.

Conditions for Updating the I/M System Status

Each system requires at least one, and sometimes several, diagnostic tests. The results of these tests are reported by a diagnostic trouble code (DTC). A system monitor is complete when either all of the DTCs comprising the monitor have Run and Passed, or any one of the DTCs comprising the monitor have illuminated the malfunction indicator lamp (MIL) . Once all of the tests are completed, the I/M System Status display will indicate YES in the Completed column.

For example, when the HO2S Heater Status indicates YES, either all of the oxygen sensor heater tests have passed or one of the tests has illuminated the MIL. If the vehicle has four heated oxygen sensors, either all four heater circuit tests have passed or one of the heater circuit tests has illuminated the MIL. The I/M System Status will indicate NO under the Completed column when any of the required tests for that system have not run. The following is a list of conditions that would set the I/M System Status indicator to NO

  1. The vehicle is new from the factory and has not yet been driven through the necessary drive conditions to complete the tests.
  2. The battery has been disconnected or discharged below operating voltage.
  3. The control module power or ground has been interrupted.
  4. The control module has been reprogrammed.
  5. The control module DTCs have been cleared as part of a service procedure.

Conditions for Clearing I/M Test DTCs

  1. Only the OBD II System can erase the I/M Test DTC. The OBD II system must determine that the malfunction that caused the I/M Test DTC to be stored is no longer present and is not commanding the MIL. Each of the following represents ways to clear an I/M Test DTC: If the MIL goes out due to 3 passing drive cycles, scan tool code clear is not used, the I/M Test DTC is erased at power down of the last drive cycle. If a scan tool code clear is used to turn OFF the MIL, the I/M Test DTC is not erased, the DTC must PASS and not FAIL. The I/M Test DTC is erased at power down of the drive cycle. If the controller is reflashed/reprogrammed, all I/M Test DTCs are erased.
  2. For the OBD II System to run a single drive cycle for clearing an I/M Test DTC, all of the following conditions must occur: Cumulative time of engine run time is greater than 600 s. Cumulative vehicle operation above 41 km/h (25 mph) for over 300 s. Continuous vehicle idle for greater than 30 s. Turn ignition OFF for 5 s and allow the code to clear.

Monitored Emission Control Systems

The OBD II system monitors all emission control systems that are on-board. Not all vehicles need every possible emission control system. For example, a vehicle may not be equipped with secondary air injection (AIR) or exhaust gas recirculation (EGR). The OBD II regulations require monitoring of the following; if equipped

  1. The air conditioning system
  2. The catalytic converter efficiency
  3. Comprehensive component monitoring-Emission related inputs and outputs
  4. The evaporative emission (EVAP) system
  5. The fuel delivery system
  6. Heated catalyst monitoring
  7. Misfire monitoring
  8. The oxygen sensor system (O2S or HO2S)
  9. The oxygen sensor heater system (HO2S heater)

For the specific DTCs required for each system, refer to Inspection/Maintenance (I/M) System DTC Table . Systems such as misfire and comprehensive components may not be listed in a system status list. These tests run continuously and do not require an I/M System Status indicator.

The I/M System Status display provides an indication of when the control module has completed the required tests. This does not necessarily mean that the test has passed, only that a decision was made. If the diagnostic fails, a DTC will indicate the failure. If a failure indication is present for a DTC associated with one of the I/M regulated systems, it may prevent other required tests from running. For example, a DTC for the control circuit of the EVAP purge solenoid may not be listed in the Inspection/Maintenance System DTC Table because it is a continuous test. If this DTC is set, the Active Tests for the EVAP system may not run.

The I/M System Status information may be useful for a technician to determine if diagnostics have run when verifying repairs.

Review the I/M System Status indicators. All I/M System Status indicators should report YES, and no I/M Test DTCs should be present.

  1. Observe the Engine DTC information with a scan tool. Verify no I/M DTCs are present. If an I/M DTC is set that would prevent the I/M System Status tests from completing, diagnose that DTC before continuing. Refer to «Inspection/Maintenance (I/M) System DTC Table»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures__inspectionmaintenance-im-system-dtc-table) .
  2. Review applicable service bulletins for software updates that would prevent the I/M System Status tests from completing. If a control module re-program or other repair is required, perform the «Inspection/Maintenance Complete System Set Procedure»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  3. Observe the I/M System Status indicators. If any I/M System Status indicators report NO, perform the «Inspection/Maintenance Complete System Set Procedure»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-48l-l20-53l-lmf-or-60l-l96-lc8-dtc-p057b-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The purpose of the Inspection/Maintenance (I/M) complete system set procedure is to satisfy the enable criteria necessary to execute all of the I/M readiness diagnostics and complete the trips for those particular diagnostics. When all I/M monitored diagnostic tests are completed, the I/M System Status indicators are set to YES. Perform the Inspection/Maintenance (I/M) Complete System Set Procedure if any I/M System Status indicators are set to NO.

Conditions for Meeting a Cold Start

  1. The ignition voltage between 10-15 V.
  2. The barometric pressure (BARO) is more than 75 kPa.
  3. The engine coolant temperature (ECT) at start-up is less than 42°C (108°F).
  4. The intake air temperature (IAT) is between 2-32°C (36-90°F).
  5. The engine is OFF for greater than 6 hours or the following conditions must be met: The start-up IAT minus start-up ECT are within 12°C (22°F). The start-up ECT minus start-up IAT are within 50°C (90°F).
  6. Fuel level is between 25-75 %.

Review the Inspection/Maintenance (I/M) System Status indicators. All I/M System Status indicators should report YES, and no I/M Test DTCs should be present.

Inspection/Maintenance (I/M) System Set Procedure

  1. Ensure that the vehicle meets the conditions for a cold start listed above. If the EVAP I/M System Status indicator displays NO, perform the EVAP Service bay test if applicable.
  2. Turn OFF all accessories; HVAC system, other electrical loads, including aftermarket/add-on equipment, etc., and open the hood.
  3. Set the vehicle parking brake and ensure the vehicle is in park for automatic transmission or neutral for manual transmission.
  4. Start and idle the engine for 2 min.
  5. Close the hood, release the parking brake and Accelerate at part throttle to 72-80 km/h (45-50 mph) with this speed maintained until the engine reaches operating temperature, 8-10 min .
  6. Continue operation under these conditions for an additional 6 min.
  7. Accelerate at part throttle to 90 km/h (55 mph) with this speed maintained for 2 min.
  8. Release the accelerator pedal for at least 10 s. This will allow the vehicle to enter the decel fuel cut off.
  9. Safely stop the vehicle, with the engine in drive for automatic or neutral with the clutch pedal depressed and parking brake applied for manual. Allow the vehicle to idle for 2 min.
  10. Shift the vehicle to park for automatic and neutral for manual. Turn OFF the ignition and exit the vehicle. Do NOT disturb the vehicle for 45 min.
  11. Observe the Inspection/Maintenance (I/M) System Status with a scan tool. All of the I/M System Status indicators should display YES. If the EVAP I/M System Status indicator displays NO, turn OFF the ignition, ensure that the vehicle meets the conditions for a cold start, and repeat steps 6-11 three more times, or until the EVAP I/M System Status indicator transitions to YES. If the indicator continues to display NO, refer to the «Inspection/Maintenance (I/M) System DTC Table»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures__inspectionmaintenance-im-system-dtc-table) to identify the DTCs that did not run. If any of the I/M System Status indicators display NO, refer to the «Inspection/Maintenance (I/M) System DTC Table»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures__inspectionmaintenance-im-system-dtc-table) for the indicator which did not display YES. The I/M System DTC Table identifies the DTCs associated with each I/M System Status Indicator.
  12. Observe the I/M Test DTC information with a scan tool. Verify there are no I/M Test DTCs present. If an I/M Test DTC is set, diagnose the DTC using the «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) , and refer to «Inspection/Maintenance System Check»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) .
  13. Observe the engine DTC information with a scan tool. Verify no DTCs are present. If a DTC is set, diagnose using the «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) , . After repairs, perform the «Inspection/Maintenance Complete System Set Procedure»(/chevrolet/express-g3500/2013-2013/remont/testing-diagnostics/#engine-controlsfuel-43-lu3-diagnostic-information-and-procedures) to verify no further DTCs are set.

Inspection/Maintenance (I/M) System DTC Table

SystemDTCs Required to Set System Status to YES
If an I/M System Status indicator did NOT update to YES during the Inspection/Maintenance Complete System Set Procedure , review each indicator and reference this table to determine each DTC associated with the I/M System Status Indicator. Each DTC listed below has specific conditions that must be met for the diagnostic to run. Included within the conditions are additional DTCs which, if set, may inhibit the DTCs listed below from running. Reviewing and operating the vehicle within the Conditions for Running for each DTC listed below will allow the I/M System Status Indicators to transition to YES.
Catalyst MonitorDTC P0420 or P0430 .
Fuel SystemDTC P219A or P219B .
Evaporative Emission (EVAP)DTC P0442 . DTC P0446 . DTC P0455 .
Oxygen SensorDTC P0133, P013A-P013F, P014A, P014B, P0153, P015A, P015B, P015C, or P015D . DTC P0134, P0140, P0154, or P0160 DTC P2270 or P2272 DTC P2271 or P2273
Oxygen Sensor HeaterDTC P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0135, P0141, P0155, or P0161

Inspection/Maintenance (I/M) System DTC Table

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/express-g3500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The purpose of the evaporative emission (EVAP) Service Bay Test is to aid in resetting the EVAP inspection/maintenance system status. For this vehicle that is equipped with the engine off natural vacuum diagnostic, the Service Bay Test uses the scan tool to initiate the engine control module (ECM) regular sequence of EVAP system DTC tests, but with different enable criteria. By using the Service Bay Test the inspection/maintenance indicator can be set without the need for multiple cold soaks.

The scan tool displays for the Service Bay Test are based on the events that occur within the following three categories

  1. The engine running portion of the tests-The vehicle must remain at rest, in Park, or in Neutral, during this portion of the test. This test inspects for large leaks, a leaking purge valve and/or vent system restrictions. The scan tool will display test progress or the reason for an abort or failure.
  2. Drive cycle-The scan tool will display time and distance needed to warm the fuel.
  3. Ignition OFF-During this portion of the test, the engine controller will remain active for up to 45 minutes when the ignition is turned OFF to allow control of the EVAP canister vent valve and run the engine off natural vacuum test. The engine controller inspects for small leaks during this period by monitoring fuel tank pressure or vacuum. If the system is sealed, there will be a pressure or vacuum change. Pressure or vacuum changes that are less than the calibrated values indicate a leak.

When the EVAP diagnostics are initiated by the Service Bay Test, the scan tool will indicate if the enable conditions listed below are not met, or will display a specific reason if the test aborts. When complete, the display will indicate that the tests passed or failed.

Conditions for Running the Test

The following conditions must be met in order to enable the Service Bay Test

  1. The battery voltage is between 11-18V.
  2. The engine coolant temperature (ECT) is less than 35°C (95°F) at start-up.
  3. The EVAP inspection/maintenance system status indicator is set to NO.
  4. The fuel level is 15-85 percent capacity and cannot be refueled during the tests.
  5. There are no DTCs displayed.
  6. The vehicle must be driven for the time and distance specified on the scan tool.
  7. The ambient air temperature is between 0-40°C (32-104°F).
  8. The ignition must remain OFF during the engine OFF portion of the test, and the vehicle must remain at rest.

Test Procedure

Note. If the Service Bay Test aborts or fails, a DTC will NOT be set.

  1. Install a scan tool.
  2. Select the Service Bay Test with the scan tool.
  3. Follow the instructions on the scan tool. If the test aborts, correct the condition for running the test, then retest. If the test fails, repair the vehicle for the condition indicated by the failure message on the scan tool.
  4. Verify that the EVAP inspection/maintenance system status is set to YES.

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Electronic Ignition System Description
• Control Module References
• Diagnostic Trouble Code (DTC) List - Vehicle
• Diagnostic Repair Verification
• Camshaft Position Sensor Replacement
• Camshaft Timing Chain, Sprocket, and Tensioner Replacement
• Engine Controls Schematics
• COMPONENT CONNECTOR END VIEWS - INDEX
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Temperature Versus Resistance
• Throttle Body Cleaning
• Altitude Versus Barometric Pressure
• Special Tools (Diagnostic Tools)
• Checking Aftermarket Accessories
• Engine Compression Test
• Restricted Exhaust
• Cooling System Leak Testing
• Cooling System Draining and Filling (Vac N Fill)
• Cooling System Draining and Filling (Static Fill Diesel)
• Engine Controls Schematics
• Throttle Actuator Control (TAC) System Description
• DTC P0641 or P0651 (ECM)
• Throttle Body Cleaning
• Altitude Versus Barometric Pressure
• DTC P0106
• Throttle Body Assembly Replacement
• Thermostat Diagnosis
• Oil Consumption Diagnosis
• Loss of Coolant
• Symptoms - Engine Exhaust
• Crankcase Ventilation System Inspection/Diagnosis
• Relay Replacement (Within an Electrical Center)
• Battery Inspection/Test
• Powertrain Component Views
• Ignition System Specifications
• Spark Plug Wire Inspection
• Spark Plug Inspection
• Crankshaft Position System Variation Learn
• Crankshaft and Bearing Cleaning and Inspection
• K20 Engine Control Module: Programming and Setup (Gasoline Engines)
• Exhaust Leakage
• Evaporative Emission Control System Description (LC8\ K07\ UFM)
• Special Tools (Diagnostic Tools)
• Evaporative Emission System Diagnosis
• Troubleshooting with a Test Lamp
• Crankcase Ventilation System Inspection/Diagnosis
• Exterior Lighting Systems Description and Operation
• Inline Harness Connector End Views
• Brake Pedal Position Sensor Learn
• Brake Pedal Position Sensor Replacement
• Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (L96)
• Engine Oil Pressure Sensor and/or Switch Replacement
• Instrument Cluster Schematics
• Power Distribution Schematics
• Electrical Center Identification Views
• Symptoms - Antilock Brake System
• Engine Control Module Description
• Data Link Communications Description and Operation
• Symptoms - Engine Mechanical
• Torque Converter Diagnosis
• Heated Oxygen and Oxygen Sensor Caution
• Engine Overheating
• K20 Engine Control Module: Scan Tool Information (LGH)
• OnStar Stolen Vehicle Slowdown Active
• Remote Vehicle Speed Limiting Description and Operation
• Symptoms - Engine Electrical
• Engine Mount Inspection
• Fuel Injector Cleaning
• Fuel Tank Fuel Pump Module Replacement
• Fuel Pressure Relief (CH-48027)
• Fuel Pressure Relief (Without CH-48027)
• Fuel Tank Draining (L59)
• Fuel Tank Draining (Without L59)
• Fuel System Cleaning
• Fuel and Evaporative Emission Pipe Warning
• Clean, Dry, Low Pressure Gas Source Caution
• Fuel and Evaporative Emission Hose/Pipe Connection Cleaning Caution
• Inspection/Maintenance (I/M) System DTC Table
• Road Test Warning
• DTC P0120-P0123, P0220, P0222, P0223, or P2135
• Evaporative Emission System Diagnosis
• Inspection/Maintenance (I/M) System DTC Table

More articles — Engine Performance