Engine Controls and Fuel - 6.6l (Lgh) - DTC P041C to DTC P04B Chevrolet Express G2500

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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 25070 Heat Gun 500-750°F

Circuit/System Verification

Engine running, observe the scan tool EGR cooler temperature Sensor 1 parameter. The reading should be within the normal range -39°C-999°C (-38°F-1830°F), and vary depending on the vehicle operating conditions.
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

Ignition OFF, disconnect the harness connector at the B130A EGR temperature Sensor 1.
Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. 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 K20 ECM.
Ignition ON, verify the scan tool EGR cooler temperature Sensor 1 parameter is -39°C (-38°F) or less. If greater than the specified range, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the K20 ECM.
Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the scan tool EGR cooler temperature Sensor 1 parameter is 999°C (1830°F) or greater. 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 K20 ECM.
If all circuits test normal, test or replace the B130A EGR temperature Sensor 1.

Component Testing

Note. The J 25070 Heat Gun 500-750°F may be used to evaluate the sensor under high temperature conditions.

Measure and record the resistance of the B130A EGR temperature Sensor 1 and compare those measurements to the Temperature Versus Resistance (Fuel Temperature Sensor) , Temperature Versus Resistance (ECT Sensors) , Temperature Versus Resistance (IAT Sensor 1) , Temperature Versus Resistance (IAT Sensor 2) , Temperature Versus Resistance (EGT Sensors) , Temperature Versus Resistance (EGR Temperature Sensors) , Temperature Versus Resistance (Emission Reduction Fluid Injector) .

If the resistance is not within the specified range for the known temperature, replace the B130A EGR temperature Sensor 1.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Exhaust Gas Recirculation Valve Temperature Sensor Replacement - Position 1»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

The diesel oxidation catalyst, main function is to control emissions of non methane hydrocarbons and soluble organic fraction. Its secondary function is to assist with the diesel particulate filter (DPF) regeneration, by obtaining and sustaining the temperature necessary for regeneration. In order to generate the high exhaust temperatures needed for regeneration, the aftertreatment system increases exhaust temperatures by injecting diesel fuel directly into the exhaust gases entering the DOC. This is accomplished by means of an ECM-controlled fuel injector called the hydrocarbon injector (HCI), also referred to as the indirect fuel injector or exhaust aftertreatment fuel injector. The fuel injector is located in the exhaust pipe upstream of the DOC. The injected fuel is converted into heat by the DOC to incinerate soot accumulated in the DPF. The engine control module (ECM) monitors the exhaust gas temperature (EGT) sensor 1 and 2 to determine if the operating temperature of the catalyst is achieved during a regeneration event.

The hydrocarbon conversion to oxygen is calculated from the heat flow in the oxidation catalyst, based on measured and modeled temperatures, to determine the efficiency of the oxidation catalyst. The modeled temperatures are calculated using the injection quantity and air mass flow. When the ECM detects that the diesel oxidation catalyst hydrocarbon conversion rate is below a calibrated threshold during an active regeneration event this DTC sets.

The hydrocarbon converted in the diesel oxidation catalyst is greater than 115 g and the hydrocarbon mass flow is greater than 0.0009 g/s.
The ECM is commanding a regeneration.
The exhaust gas temperature sensor 1 is greater than 250°C (482°F).
The engine speed is between 700-3,400 RPM.
The barometric pressure (BARO) is greater than 74.8 kPa (10.8 psi).
The ambient air temperature is greater than -7°C (19.4°F).
DTC P0420 runs once per driving cycle when the above conditions are met.

The ECM determines that the efficiency of the diesel oxidation catalyst has degraded below a calibrated threshold.

DTC P0420 is a Type B DTC.
DPF regeneration is inhibited.

DTC P0420 is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The use of off road red dye fuel or continuing use of non ultra low sulfur fuel may be a contributor to diesel oxidation catalyst failure.
If exhaust gas temperature sensor 4 is greater than exhaust gas temperature sensor 2 during an extended (greater than 5 min) steady state DPF regeneration event, the fuel from the indirect fuel injector is being consumed in the DPF. This may indicate that the diesel oxidation catalyst is not functioning properly.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Ignition ON.
Verify DTC P003A, P0047, P0048, P0101, P0201-P0208, P02E0, P02E2, P02E3, P02E7-P02E9, P02EB, P0300-P0308, P0402, P0545, P0546, P1048, P1049, P10CC, P10CD, P10CE, P2032, P2033, P2047, P2048, P2049, P20CB, P20CC, P20CD, or P20CE is not set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) If no DTC is set
Engine running, observe the DTC information with a scan tool. DTC P0420 should not be set. If the DTC is set Refer to Circuit/System Testing If the DTC is not set
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.
Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing If the DTC does not set
All OK.

Verify the following conditions do not exist with the exhaust system: Exhaust leaks before or after the diesel oxidation catalyst. Refer to «Exhaust Leakage»(/chevrolet/express-g2500/2013-2013/remont/exhaust/#engine-exhaust-system__exhaust-leakage) for further diagnosis. Physical damage Loose or missing hardware If a condition is found Repair or replace the affected exhaust system components as necessary If no condition is found
Verify the following conditions do not exist with the diesel oxidation catalyst: Physical damage or alterations Internal rattles caused by a damaged catalyst substrate Restrictions If a condition is found Replace the diesel oxidation catalyst If no condition is found
Observe the scan tool Freeze Frame/Failure Records data for DTC P0420. Determine the temperature difference between EGT Sensor 1 and 2 and between EGT Sensor 2 and 4. If Exhaust Gas Temperature Sensor 4 is greater than Exhaust Gas Temperature Sensor 2 by at least 100°C (180° F) and Exhaust Gas Temperature Sensor 2 is within 100°C (180° F) of Exhaust Gas Temperature Sensor 1 Replace the diesel oxidation catalyst If Exhaust Gas Temperature Sensor 4 is not greater than Exhaust Gas Temperature Sensor 2 by at least 100°C (180° F) and Exhaust Gas Temperature Sensor 2 is greater than 100°C (180° F) of Exhaust Gas Temperature Sensor 1
Test the Q57 Indirect fuel injector flow. Refer to «Exhaust Aftertreatment Fuel Injector Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) .
Verify the following conditions do not exist: Off road fuel or red dye fuel Low quality B20 fuel Fuel containing high sulfur content Engine oil or coolant consumption If a condition is found Repair as necessary If no condition is found
If all components test normal and no conditions are found, 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. If the DTC sets Refer to Circuit/System Testing - step 1 If the DTC does not set
All OK.

Perform the Diagnostic Repair Verification after completing the repair.

«Catalytic Converter Replacement (LGH)»(/chevrolet/express-g2500/2013-2013/remont/exhaust/#engine-exhaust-system)
If the scan tool DPF Soot Mass is 40 g or greater, perform the «Diesel Particulate Filter (DPF) Service Regeneration»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) procedure.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
5 V Reference	P0406, P046C, P06A3, P2495	P0406, P046C	P0406, P06A3, P2495	P046C
EGR Valve Position Sensor Signal	P0405	P0406, P046C	P0406	P046C
Low Reference		P0406, P046C		P046C

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Engine Running Parameter Normal Range: 0.25-4.8 V
5 V Reference	5.0 V	5.0 V	5.0 V
EGR Valve Position Sensor Signal	0 V	5.0 V	5.0 V
Low Reference		5.0 V

EGR Position Sensor

The engine control module (ECM) uses the exhaust gas recirculation (EGR) position sensor to determine the position of the EGR valve. The ECM sends a reference voltage through the 5-volt reference circuit to the EGR position sensor. The ECM provides a voltage return path for the sensor through the low reference circuit. A variable voltage signal, based on the EGR valve position, is sent from the sensor to the ECM through the EGR position sensor signal circuit. The ECM compares the actual EGR position with the desired EGR position when the EGR valve is commanded open or closed.

The EGR valve is controlled by the ECM through the EGR motor high control and the EGR motor low control circuits. The ECM supplies voltage that is near ignition voltage to the high and low control circuits at all times. The ECM will pulse width modulate the low control circuit to ground when EGR is desired. The lower the pulse width, the more the valve will open. The ECM will pulse width modulate the high control circuit to ground when the EGR valve is desired closed.

Engine speed is greater than 600 RPM.
The Battery voltage is greater than 11 V.
The Air Intake Heater duty cycle is less than 5 %.
The EGR Valve is active.
The EGR Valve offset learning from the previous drive cycle is complete.
EGR offset learning is not active.
DTC P046C runs continuously when the above conditions are met.

The ECM detects that the difference between the actual EGR position and the desired EGR position is greater than 5 % or less than -5 % for greater than 8 s.

DTC P046C is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Ignition ON, observe the scan tool DTC information. Verify DTC P0401, P0402, P0403, P0405, P0406, or P06A3 is not set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.
Ignition ON, observe the scan tool Desired EGR Position and the EGR Position Sensor parameters. Command the EGR valve from 0-40 % with a scan tool. The parameters should increment and remain within 3 % throughout the commanded range.
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.

Ignition OFF, remove the Q14 EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement . Inspect the Q14 EGR valve for the conditions listed below

A sticking, binding or frozen EGR valve
Any coking, soot build up, debris or damage that can cause the EGR valve to stick partially open or closed If a condition is found, clean or replace the Q14 EGR Valve as necessary.

Perform the Diagnostic Repair Verification after completing the repair.

«Exhaust Gas Recirculation Valve Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming and setup

The offset of the EGR valve is checked after the offset learning has been completed in after-run/post drive. The difference between the maximum and minimum EGR valve offset values is calculated by the Engine Control Module (ECM). If the difference is above a calibrated threshold or the offset learned value is not within a calibrated range, a fault is recognized. While the offset learning is active, the EGR valve is checked for a jammed valve. If the valve is stuck during opening or closing for a calibrated time, a fault is reported. If either of these conditions occur, the DTC will be set.

DTC P0403, P0405, P0406, or P140F is not set.
The ignition is OFF and the engine is in after-run/post drive.
The EGR Valve offset learning procedure is active or complete for current drive cycle.
The Engine Coolant Temperature (ECT) is between 5-123°C (41-253°F).
Battery voltage is greater than 10 V.
The DTC runs continuously when the above conditions are met.

The ECM detects that the difference between the minimum and maximum EGR valve learned offset values is greater than 30%. OR
The ECM detects that the offset learned value for the EGR valve is not within a calibrated range. OR
The ECM detects a jammed EGR valve during opening or closing the valve for greater than 5 s.

DTC P049D is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References

Note. Occasionally, when using an EGR device control, Engine Reduced Power and Clean Exhaust Filter messages may occur after a short delay when commanding large EGR positions. The messages are a result of ECM protecting hardware during device control mode. No DTCs will be stored and the Diesel Particulate Filter does not need to be service cleaned. Exiting device control will restore normal function.

Ignition ON, observe the scan tool DTC information. Verify DTC P0403 is not set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.
Ignition ON, observe the scan tool Desired EGR Position and the EGR Position Sensor parameters. Command the EGR valve from 0 to 40 % with a scan tool. The parameters should respond and remain within 3 % throughout the commanded range.
Engine running command the EGR Valve to 40 % with a scan tool, then increase the engine speed to 2,500 RPM. The engine should run rough.
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. Perform the Circuit System Verification before proceeding with Circuit/System Testing.

Ignition OFF, remove the Q14 EGR valve. Refer to «Exhaust Gas Recirculation Valve Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) .
Inspect the Q14 EGR valve for the following conditions: A sticking, binding, or frozen EGR valve Any coking, soot build up, debris or damage that can cause the EGR valve to stick partially open or closed If a condition is found, replace the Q14 EGR Valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Exhaust Gas Recirculation Valve Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming and setup

The engine control module (ECM) adjusts the fuel delivery in order to control crankshaft speed at idle. The ECM monitors the engine speed and will detect an out of range idle speed for the amount of fuel that is delivered.

The engine is operating for greater than 180 s.
The engine speed is greater than 300 RPM.
The engine coolant temperature (ECT) is between -7 to +123°C (19-253°F).
The vehicle speed is less than 3 km/h (2 mph).
DTC P0506 and P0507 run continuously when the above conditions are met.

P0506

The ECM detects the actual idle speed is below a predetermined speed for greater than 20 s.

P0507

The ECM detects the actual idle speed is above a predetermined speed for greater than 20 s.

DTCs P0506 and P0507 are type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Schematic Reference

Connector End Views

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Ignition ON.
Verify there are no other DTCs set. If any other DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/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
Engine idling at the normal operating temperature.
Verify the scan tool Engine Speed parameter is within 200 RPM of the Desired Idle Speed parameter. If not within 200 RPM of the Desired Idle Speed Refer to Circuit/System Testing. If within 200 RPM of the Desired Idle Speed
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.
Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set.
All OK.

Verify none of the following conditions exist

P0506

Verify the conditions listed below do not exist: A crankcase overfill can cause oil to be forced through the positive crankcase ventilation (PCV) system. 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
All OK.

P0507

Verify the conditions listed below do not exist: An outside source that has allowed oil or fuel to enter the air induction system. Fuel in engine oil being drawn into the engine. An aftermarket performance kit using an external fuel source. If a condition is found Repair as necessary. If a condition is not found
All OK.

Perform the Diagnostic Repair Verification after completing the repair.

Circuit	Short to Ground	High Resistance	Open	Short to Voltage
Engine Oil Pressure 5-Volt Reference	P0522	1	P0522	P0523
Engine Oil Pressure Sensor Signal	P0522	1	P0522	P0523
Low Reference		1	P0523
1. Engine Oil Pressure Indicator Malfunction

The engine oil pressure (EOP) sensor changes voltage based on the engine oil pressure. The EOP sensor is a 3-wire sensor comprising of the signal circuit, the low reference circuit and the 5-volt reference circuit. The engine control module (ECM) supplies 5 volts to the EOP sensor via the 5-volt reference circuit and provides ground via the EOP low reference circuit. The ECM monitors the signal circuit of the EOP sensor to determine the EOP sensor voltage is within the normal operating range of approximately 1-4 volts. When the engine oil pressure is high, the EOP sensor voltage is high and the ECM senses a high signal voltage. When the engine oil pressure is low, the EOP sensor voltage is low and the ECM senses a low signal voltage. The ECM sends the EOP information to the instrument panel cluster (IPC) via the serial data circuit.

The engine is running.

P0522

The ECM detects that the EOP sensor signal circuit is less than 0.1 volt.
The above condition is present for greater than 10 seconds.

P0523

The ECM detects that the EOP sensor signal circuit is greater than 4.4 volts.
The above condition is present for greater than 10 seconds.

The ECM records the operating conditions at the time the diagnostics test fails. The ECM displays this information in the Failure Records on the scan tool.
The IPC illuminates the EOP indicator.

The DTC becomes history when the conditions for setting the DTC are no longer present.
The history DTC clears after 40 malfunction-free warm-up cycles.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Instrument Cluster Description and Operation

Description and Operation

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Engine running, observe the scan tool Engine Oil Pressure Sensor parameter. The reading should be between 41-448 kPa (6-65 psi).
Verify the engine oil pressure. Refer to «Oil Pressure Diagnosis and Testing»(/chevrolet/express-g2500/2013-2013/remont/mechanical/#engine-mechanical-66l-lgh-diagnostic-information-and-procedures__oil-pressure-diagnosis-and-testing) .

Ignition OFF, disconnect the harness connector at the engine oil pressure (EOP) sensor.
Ignition OFF, test for less than 1.0 ohms between the low reference terminal 3 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.
Ignition ON, test for 4.8-5.2 volts between the 5-volt reference terminal 2 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.
Verify the scan tool Engine Oil Pressure Sensor parameter is less than 8 kPa (1.2 psi). If greater than the specified range, test the signal circuit terminal listed below for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
Install a 3 A fused jumper wire between the signal circuit terminal and the 5-volt reference circuit terminal listed below. Verify the scan tool Engine Oil Pressure Sensor parameter is greater than 550 kPa (80 psi). Signal Terminal 1 5-Volt Reference Terminal 2 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.
If all circuits test normal, test or replace the EOP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Engine Oil Pressure Sensor and/or Switch Replacement»(/chevrolet/express-g2500/2013-2013/remont/mechanical/#engine-mechanical-66l-lgh-repair-instructions-on-vehicle)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Circuit	Short to Ground	Open	High Resistance	Short to Voltage	Signal Performance
Exhaust Gas Temperature Sensor 1 Signal	P0545	P0546	P20E2, P2080	P0546*	P20E2, P2080
Exhaust Gas Temperature Sensor 1 Low Reference		P0546	P20E2, P2080	P0546*	P20E2, P2080
Exhaust Gas Temperature Sensor 2 Signal	P2032	P2033	P20E2, P2084	P2033*	P20E2, P2084
Exhaust Gas Temperature Sensor 2 Low Reference		P2033	P20E2, P2084	P2033*	P20E2, P2084
Exhaust Gas Temperature Sensor 3 Signal	P242C	P242D	P113A, P242B	P242D*	P113A, P242B
Exhaust Gas Temperature Sensor 3 Low Reference		P242D	P113A, P242B	P242D*	P113A, P242B
Exhaust Gas Temperature Sensor 4 Signal	P2470	P2471	P113A, P246F	P2471*	P113A, P246F
Exhaust Gas Temperature Sensor 4 Low Reference		P2471	P113A, P246F	P2471*	P113A, P246F
* Internal ECM or Sensor damage may occur if the circuit is shorted to B+

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition ON Parameter Normal Range: -39 to +999°C (-38 to +1,830°F)
Exhaust Gas Temperature Sensor 1-4 Signal	40°C (-40°F)	1,000°C (1,832°F)	1,000°C (1,832°F)
Exhaust Gas Temperature Sensor 1-4 Low Reference		1,000°C (1,832°F)	1,000°C (1,832°F)

EGT Sensor 1-4

The exhaust gas temperature sensors are variable resistors that measure the temperature of the exhaust at the inlet and outlet of the diesel oxidation catalyst as well as the inlet and outlet of the diesel particulate filter (DPF). The engine control module (ECM) supplies a bias 5-volt signal to the exhaust gas temperature sensor signal circuit, and supplies a ground to the low reference circuit. The exhaust gas temperature information is used by the ECM during the particulate filter cleaning process.

The following table illustrates the relationship between the temperature of the exhaust gas and the resistance and voltage at the exhaust gas temperature sensor.

Temperature	Resistance	Voltage
Low	Low	Low
High	High	High

The ignition is ON or the engine is running.
The DTCs run continuously when the above conditions are met.

P0545, P2032, P242C and P2470

The ECM detects that the exhaust gas temperature sensor voltage is less than 0.65 V for greater than 5 s.

P0546, P2033, P242D and P2471

The ECM detects that the exhaust gas temperature sensor voltage is greater than 2.21 V for greater than 5 s.

P0545, P0546, P2470 and P2471

DTCs P0545, P0546, P2470 and P2471 are Type B DTCs.

P2032

DTC P2032 is a Type A DTC.
Diesel particulate filter regeneration is inhibited.
Emission control warning strategy is activated. Refer to «Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Quality)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Level)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Emission Control)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Anti-Tampering)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) for more information.

P2033

DTC P2033 is a Type A DTC.
Diesel particulate filter regeneration is inhibited.
Selective catalyst reductant dosing is inhibited.
Emission control warning strategy is activated. Refer to «Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Quality)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Level)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Emission Control)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Anti-Tampering)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) for more information.

P242C and P242D

DTCs P242C and P242D are Type A DTCs.
Selective catalyst reductant dosing is inhibited.
Emission control warning strategy is activated. Refer to «Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Quality)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Level)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Emission Control)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Anti-Tampering)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) for more information.

DTCs P0545, P0546, P2470 and P2471 are Type B DTCs.
DTCs P2032, P2033, P242C and P242D are Type A DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Inspect the exhaust gas temperature sensor terminals for corrosion.
Exhaust gas temperature sensors may fail intermittently while operating under extreme temperatures. Review the Freeze Frame Failure Records to verify the failure criteria.
A plot of scan tool EGT sensor snapshot data taken while the engine is running at extreme temperatures may increase the ability to diagnose an intermittent EGT sensor.
A short to a separate 5 V source will cause this DTC to set.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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 25070 Heat Gun 500-750°F

Ignition ON.
Verify DTC P113A, P20E2, P2080, P2084, P242B, or P246F is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) If none of the DTCs are set
Engine running at operating temperature.
Increase engine speed to 2,500 RPM for 5 minutes while observing the appropriate scan tool Exhaust Gas Temperature (EGT) Sensor 1-4 parameter. The temperature should increase smoothly within the normal range of -39 to +999°C (-38 to +1,830°F) with no spikes or dropouts. If spikes or dropouts occur Refer to Circuit/System Testing. If no spikes or dropouts occur
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.
Verify a DTC does not set. If any DTC sets Refer to Circuit/System Testing. If a DTC does not set
All OK.

Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate B131 Exhaust Gas Temperature sensor. It may take up to 2 minutes for all vehicle systems to power down.
Test for less than 5 ohms between the low reference circuit terminal B 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
Ignition ON.
Verify the scan tool B131 EGT sensor parameter is greater than 998°C (1828°F). If 998°C (1828°F) or less Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit terminal A 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 greater than 998°C (1828°F)
Install a 3 A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B.
Verify the scan tool B131 Exhaust Gas Temperature (EGT) parameter is less than -35°C (-31°F). If -35°C (-31°F) 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 Ignition OFF 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 less than -35°C (-31°F)
Test or replace the B131 Exhaust Gas Temperature sensor.

Ignition OFF, remove the affected B131 Exhaust Gas Temperature sensor while leaving the harness connector connected.
Measure and record the resistance of the B131 Exhaust Gas Temperature sensor and compare the measurements to the «Temperature Versus Resistance (Fuel Temperature Sensor)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-fuel-temperature-sensor) , «Temperature Versus Resistance (ECT Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-ect-sensors) , «Temperature Versus Resistance (IAT Sensor 1)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-iat-sensor-1) , «Temperature Versus Resistance (IAT Sensor 2)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-iat-sensor-2) , «Temperature Versus Resistance (EGT Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-egt-sensors) , «Temperature Versus Resistance (EGR Temperature Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-egr-temperature-sensors) , «Temperature Versus Resistance (Emission Reduction Fluid Injector)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-emission-reduction-fluid) chart. If not within the specified range Replace the B131 Exhaust Gas Temperature sensor. If within the specified range
All OK

«Exhaust Temperature Sensor Replacement - Position 1»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Exhaust Temperature Sensor Replacement - Position 2»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Exhaust Temperature Sensor Replacement - Position 3»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Exhaust Temperature Sensor Replacement - Position 4»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
Perform the scan tool «Diesel Particulate Filter (DPF) Regeneration Enable»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__diesel-particulate-filter-dpf-regeneration-enable) , procedure if the scan tool DPF Soot Mass is less than 30 g. If the scan tool DPF Soot Mass is 30 g or greater, perform the «Diesel Particulate Filter (DPF) Service Regeneration»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) procedure.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Repair Verification

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming or setup procedures that are required when a component or module is removed or replaced.
Clear the DTCs.
Ignition OFF, all vehicle systems OFF, including retained accessory power (RAP) and the scan tool. This may take up to 2 minutes.
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.
Verify the DTC does not set. If the DTC sets A condition with the system still exists If a DTC does not set
Ignition ON, perform the Reductant System Data Reset with a scan tool in order to clear the reductant lamp, if illuminated. If the reductant lamp does not turn OFF A condition with the system still exists If the reductant lamp does turn OFF
All OK.

The idle speed directly depends on the injection quantity. The monitor compares the commanded injection quantity with calculated thresholds. The commanded idle fuel needs to be between 50 percent of max and min expected fuel. The expected fuel is dependent on accessory loads, Ambient temperature, baro, and engine speed.

If the actual injection quantity is lower than a calculated threshold a "Fuel Quantity Lower Than Expected" fault will be set.

If the actual injection quantity is higher than a calculated threshold a "Fuel Quantity Higher Than Expected" fault will be set.

Ambient air temperature is above -7°C (19°F).
Engine temperature is greater than -20°C (-4°F).
Engine speed is between 476-1040 RPM.
Accelerator pedal position is 0 percent.
Vehicle speed is less than 3 km/h (1.8 mph).
Transmission not in Park or Neutral.
No gear change has occurred.
PTO not engaged.
Diesel Particulate Filter (DPF) Regeneration not active.
No other DTCs are present.
The DTC runs continuously when the above conditions exist.

A fault is detected when the current fuel injection quantity is lower than the allowed limit for greater than 30 seconds.

DTCs P054E and P054F are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Contaminated or improper fuel quality may cause this DTC to set.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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.

Ignition ON.
Observe the DTC information with a scan tool. Verify no other DTCs are set. If other DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If no other DTCs are set
Verify there are no aftermarket performance enhancing devices installed on the vehicle.
Worn or failed accessory drive components may cause this DTC to set.
Verify the proper fuel is used. Refer to «Fuel System Specifications»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications) , and «Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures__contaminants-in-fuel-diagnosis) .
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. If DTC resets Refer to Diagnostic Aids. If DTC does not reset
All OK.

Perform the Diagnostic Repair Verification after completing the repair.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Signal	P057C	P057C	P057D	P057B
5 V Reference	P057C P0651	P057C	P0651
Low Reference		P057D	P057D

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition ON. Brake Pedal Position Sensor Parameter Normal Range: 0.25-4.75 V
5 V Reference	0 V	0 V
Signal	0 V	0 V	5 V
Low Reference		5 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 .

Ignition voltage is greater than 10 V.
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.

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

P057B, P057C, and P057D are Type A DTCs

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

«Engine Controls Schematics»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-wiring-schematic-diagrams)
«Exterior Lights Schematics»(/chevrolet/express-g2500/2013-2013/remont/exterior-lights/#lighting-system)

Connector End View Reference

«COMPONENT CONNECTOR END VIEWS - INDEX»(/chevrolet/express-g2500/2013-2013/remont/body-electrical/#wiring-systems-and-power-management-component-connector-end-views-index)
«INLINE HARNESS CONNECTOR END VIEWS - INDEX»(/chevrolet/express-g2500/2013-2013/remont/body-electrical/#wiring-systems-and-power-management-inline-harness-connector-end-views-index)

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

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-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If none of the DTCs are set
Ignition ON, transmission in Park, and service brake pedal released.
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
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
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-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__brake-pedal-position-sensor-learn) . If difference is 0.1 V or less
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
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.
Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
All OK.

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.
Test for less than 10 ohms between the low reference circuit terminal 5 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
Ignition ON.
Test for 4.8-5.2 V between the 5 V reference circuit terminal 6 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
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
Install a 3 A fused jumper wire between the signal circuit terminal 4 and the 5 V reference circuit terminal 6.
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
Replace the B22 Brake Pedal Position Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

«Brake Pedal Position Sensor Replacement»(/chevrolet/express-g2500/2013-2013/remont/exterior-lights/#lighting-system__brake-pedal-position-sensor-replacement)
Perform the «Brake Pedal Position Sensor Learn»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-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.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Engine Control Module replacement, programming and setup.

Description

These DTCs apply to internal microprocessor integrity conditions within the engine control module (ECM). 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.

P0601, P0602, P2610

These DTCs run once per ignition cycle.

P0606

DTCs P2146, P2149, P2152, P2155 are not set.
The engine speed is greater than 1,200 RPM.
The battery voltage is greater than 8 V.
DTC P0606 runs continuously when the above conditions are met.

P060B, P062F

These DTCs run continuously when the ignition is ON.

P061C

DTC P061C runs continuously when the engine is running.

P0601, P0602, P0606, P060B, P061C, P062F, P2610

The ECM detects an internal failure or incomplete programming for greater than 30 s.

P2610

The ECM detects an interruption of its permanent battery voltage supply.

DTCs P0601, P0602, P0606, P060B, and P062F are Type A DTCs.
DTCs P061C and P2610 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0601, P0602, P0606, P060B, and P062F are Type A DTCs.
DTCs P061C and P2610 are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

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

The battery cables are clean and tight, and the battery is fully charged. Refer to «Battery Inspection/Test»(/chevrolet/express-g2500/2013-2013/remont/charging-system/#battery-charging-system-and-starting-system) .
The ECM ground circuits do not have an open or high resistance.
The ECM power circuits do not have an open, short to ground, or high resistance.

Schematic Reference

Connector End View Reference

Component View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Observe the DTC information with a scan tool. DTC P0601, P0602, P0606, P060B, P061C, P062F, or P2610 should not set.
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.

Ignition ON, verify that other DTCs are not set. If any other DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Ignition ON, clear the DTC information with a scan tool.
Ignition OFF and all vehicle systems OFF, disconnect the scan tool.
Wait at least 2 minutes for the K20 Engine Control Module to power down completely.
Reconnect the scan tool.
Ignition ON, observe the DTC information with a scan tool.
If DTC P2610 failed this ignition, test for B+ at the K20 Engine Control Module connector battery positive voltage circuit terminal X1-67. If not the specified value, test the battery positive voltage circuit for an open/high resistance or a short to ground.
Test for less than 2 ohms between ground and the ECM connector ground circuits terminals X2-73 and X3-73. If greater than the specified value, test the ground circuits for an open/high resistance.
If all circuits test normal, replace the K20 Engine Control Module.
If DTC P2610 is not set, observe the DTC information with a scan tool. If DTC P0602 is set, program the K20 Engine Control Module. Refer to «Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) . If DTC P0602 resets, replace the K20 Engine Control Module. If DTC P0601, P0606, P060B, P061C, or P062F failed this ignition, replace the K20 Engine Control Module.

Perform the Diagnostic Repair Verification after completing the repair.

If DTC P0606 was set, perform the scan tool «Diesel Particulate Filter (DPF) Regeneration Enable»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__diesel-particulate-filter-dpf-regeneration-enable) , procedure if the scan tool DPF Soot Mass is less than 30 g. If the scan tool DPF Soot Mass is 30 g or greater, perform the «Diesel Particulate Filter (DPF) Service Regeneration»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) procedure.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Fuel Pump Relay Control Circuit	P0628	P0627	P0629

The engine control module (ECM) provides ignition voltage to the fuel pump relay control circuit whenever the engine is cranking or running. The ECM enables the fuel pump relay as long as the engine is cranking or running, and crank sensor reference pulses are received. The ECM monitors the voltage on the control circuit and sets a DTC if a fault is detected.

The engine speed is greater than 80 RPM.
The ignition 1 signal parameter is 10-18 V.
The ECM has commanded the fuel pump relay control circuit ON and OFF at least once during the ignition cycle.
The DTCs run continuously when the conditions above are met.

P0627

The ECM detects the fuel pump relay control circuit voltage is less than 2.74 V when the control circuit is commanded OFF.
The above condition exists for greater than 4 seconds, or a cumulative of 30 seconds.

P0628

The ECM detects the fuel pump relay control circuit voltage is less than 2.21 V when the control circuit is commanded ON.
The above condition exists for greater than 4 seconds, or a cumulative of 30 seconds.

P0629

The ECM detects the fuel pump relay control circuit voltage is greater than 2.21 V when the control circuit is commanded OFF.
The above condition exists for greater than 4 seconds, or a cumulative of 30 seconds.

DTCs P0627, P0628, and P0629 are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Ignition ON.
Command the fuel pump relay ON and OFF with a scan tool. You should hear and feel a click when you command the fuel pump relay ON and OFF. If a click is not heard or felt Refer to Circuit/System Testing. If a click is heard or felt
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. If DTC resets Refer to Circuit/System Testing. If DTC does not reset
All OK.

Ignition OFF.
Remove the fuel pump relay from the electrical center with the J 43244 Relay Puller Pliers.
Test for less than 5 ohms between the ground circuit terminal 85 and ground . If greater than 5 ohms Repair the open/high resistance in the ground circuit. If less than 5 ohms
Connect a test lamp between the relay control circuit terminal 86 and ground.
Ignition ON.
Command the fuel pump relay ON and OFF with a scan tool. The test lamp should turn ON and OFF with each command. If the test lamp is always ON Test the relay control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module. If the test lamp is always OFF Test the relay control circuit for a short to ground or an open/high resistance. If circuit tests normal, replace the K20 Engine Control Module. If the test lamp turns ON and OFF
Replace the KR107 Fuel Pump Relay.

Ignition OFF.
Remove the KR107 Fuel Pump Relay from the electrical center with the J 43244 Relay Puller Pliers.
Test for 70 to110 ohms between terminals 85 and 86 of the KR107 fuel pump relay. If not within 70 to 110 ohms Replace the KR107 Fuel Pump Relay. If within 70 to 110 ohms
Test for infinite resistance between the following relay terminals: 30 and 86 30 and 87 30 and 85 85 and 87 If there is not infinite resistance Replace the KR107 Fuel Pump Relay. If there is infinite resistance
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 relay terminals 30 and 87. If greater than 2 ohms Replace the KR107 Fuel Pump Relay. If less than 2 ohms
All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Relay Replacement (Within an Electrical Center)»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) , «Relay Replacement (Attached to Wire Harness)»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Intake Air Heater Signal			P0640

The intake air heater (IAH) is located at the intake manifold outlet and is used to heat the air before it enters the inner cooler during cold engine operation. The engine control module (ECM) determines when to request the glow plug control module to turn ON and OFF the intake air heater. The glow plug control module controls the intake air heater current by monitoring the feedback circuits of the intake air heater. The intake air heater will only be commanded ON while the engine is running if required by the ECM.

The Intake Air Heater is commanded OFF.
DTC P0640 runs continuously when the above condition is met.

The glow plug control module detects voltage on the Intake Air Heater Signal circuit for greater than 2 s when the intake air heater is commanded OFF.

DTC P0640 is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Verify the scan tool Intake Air Heater Control Circuit 1 Command Status parameter displays OK. If scan tool displays Malfunction Refer to Circuit/System Testing. If scan tool displays OK
Verify the Intake Air Heater can be commanded ON with the scan tool. If IAH cannot be commanded ON Refer to Circuit/System Testing. If IAH can be commanded ON
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. If DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

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

Ignition OFF.
Disconnect the harness connector at the E24 Intake Air Heater.
Ignition ON.
Test for less than 2 V between the Intake Air Heater Signal circuit terminal 2 and ground. If greater than 2 V Test the Intake Air Heater Signal circuit for a short to voltage. If the circuit tests normal, replace the K34 Glow Plug Control Module. If less than 2 v
Replace the E24 Intake Air Heater.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Intake Air Heater Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for glow plug control module replacement, programming, and setup.

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

DTCs P0641, P0651, P0697, P06A3, and P06D2 run continuously when the ignition is ON and battery voltage is greater than 11 V for greater than 3 s.

The ECM detects a short to ground or voltage on any of the 5V reference circuits for greater than 1 s.

DTCs P0641, P0651, and P0697 are Type A DTCs.
DTCs P06A3 and P06D2 are Type B DTCs.

DTCs P0641, P0651, and P0697 are Type A DTCs.
DTCs P06A3 and P06D2 are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

DTC P0641

The 5V reference 1 circuit provides 5 V to the sensors listed below

Engine oil pressure sensor
Fuel rail pressure sensor
Air conditioning (A/C) refrigerant pressure sensor
Exhaust pressure differential sensor
Camshaft position sensor

DTC P0651

The 5V reference 2 circuit provides 5 V to the sensors listed below

Accelerator pedal position sensor 2
Manifold absolute pressure sensor
Brake pedal position sensor

DTC P0697

The 5V reference 3 circuit provides 5 V to the sensors listed below

Intake air valve position sensor
Accelerator pedal position sensor 1

DTC P06A3

The 5V reference 4 circuit provides 5 V to the exhaust gas recirculation position sensor.

DTC P06D2

The 5V reference 5 circuit provides 5 V to the sensors listed below

Crankshaft position sensor
Cooling fan speed sensor
Diesel exhaust fluid pressure sensor
Turbocharger vane 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

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Ignition ON, observe the DTC information with a scan tool. DTC P0641, P0651, P0697, P06A3, or P06D2 should not set.
Observe the circuit status parameters listed below: 5V Reference 1 Circuit Status 5V Reference 2 Circuit Status 5V Reference 3 Circuit Status 5V Reference 4 Circuit Status 5V Reference 5 Circuit Status Each parameter should display OK.
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.

Ignition OFF, disconnect the harness connector of all appropriate sensors for the applicable DTC. Refer to Diagnostic Aids.
Ignition ON, test for 4.8-5.2 V between one of the affected 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.
Connect each component associated with the affected 5V reference circuit, one at a time, while monitoring the appropriate scan tool 5V Reference 1, 2, 3, 4, or 5 Circuit Status parameter. The parameter should continue to display OK. If the parameter displays Malfunction when a component is connected, test the signal circuit of the component for a short to voltage. If the circuit tests normal, replace the component.

Perform the Diagnostic Repair Verification after completing the repair.

«Accelerator Pedal Position Sensor Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__accelerator-pedal-position-sensor-replacement)
«Air Conditioning Cycling Switch Replacement»(/chevrolet/express-g2500/2013-2013/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning)
«Camshaft Position Sensor Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Crankshaft Position Sensor Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Emission Reduction Fluid Tank Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Engine Oil Pressure Sensor and/or Switch Replacement»(/chevrolet/express-g2500/2013-2013/remont/mechanical/#engine-mechanical-66l-lgh-repair-instructions-on-vehicle)
«Exhaust Gas Recirculation Valve Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Exhaust Pressure Differential Sensor Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Fan Clutch Replacement»(/chevrolet/express-g2500/2013-2013/remont/cooling-system-mechanical/#engine-cooling-system)
«Fuel Injection Fuel Rail Fuel Pressure Sensor Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Throttle Body Assembly Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Manifold Absolute Pressure Sensor Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Turbocharger Vane Position Sensor Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.

The glow plug control module has the ability to perform internal self-test diagnostics. If the glow plug control module detects a failure in any of the internal self-tests it will send a message to the engine control module (ECM) to set this DTC.

The ignition is ON.
DTC P064C runs continuously.

The glow plug control module detects a fault in one or more of the internal self-test diagnostics.

DTC P064C is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Intermittent or poor connection of the glow plug control module X2 connector may cause this DTC to set.
Poor glow plug control module ground may cause this DTC to set.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

If you cannot duplicate the conditions, refer to «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures) .
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. If DTC resets Refer to Circuit/System Testing. If DTC does not reset
All OK.

Ignition OFF.
Disconnect the harness connector X2 at the K34 glow plug control module.
Ignition ON.
Verify that a test lamp illuminates between the Run/Crank Ignition 1 Voltage circuit terminal 33 and ground. If the test lamp does not illuminate Repair the open or high resistance in the Run/Crank Ignition 1 Voltage circuit. If the test lamp illuminates
Verify that a test lamp illuminates between the Run/Crank Ignition 1 Voltage circuit terminal 33 and the Signal Ground circuit terminal 10 If the test lamp does not illuminate Repair the open or high resistance in the Signal Ground circuit. If the test lamp illuminates
Replace the K34 glow plug control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for glow plug control module replacement, setup, and programming

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
MIL Voltage Supply	P0650	P0650
MIL Control	P0650*	P0650	P0650
*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.

The ignition is ON.
The ECM has commanded the MIL ON and OFF at least once during the ignition cycle.
The DTC runs continuously when the above conditions are met.

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

DTC P0650 is a Type A DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

«Engine Controls Schematics»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-wiring-schematic-diagrams)
«Instrument Cluster Schematics»(/chevrolet/express-g2500/2013-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Ignition ON, command the MIL ON and OFF with a scan tool. The MIL should turn ON and OFF as commanded.
Ignition ON, observe each of the MIL Control Circuit Test parameters listed below with a scan tool: The MIL Ckt Short Gnd Test Status The MIL Ckt Open Test Status The MIL Ckt Short Volts Test Status Each parameter should display OK or Not Run.
Engine running, observe each of the MIL Control Circuit Test parameters listed below with a scan tool: The MIL Ckt Short Gnd Test Status The MIL Ckt Open Test Status The MIL Ckt Short Volts Test Status Each parameter should display OK or Not Run.
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.

Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module.
Ignition ON, the MIL should not illuminate. If the MIL is illuminated, test the MIL control circuit terminal X1-17 for a short to ground. If the circuit tests normal, replace the IPC.
Connect a 3 A fused jumper wire between the MIL control circuit terminal X1-17 and ground. The MIL should illuminate. If the MIL illuminates, replace the K20 Engine Control Module. If the MIL does not illuminate, test the MIL control circuit for a short to voltage or an open/high resistance. If the MIL control circuit tests OK, test the cluster ignition circuit terminal 19 for a short to ground or open/high resistance. If the circuits test normal, replace the IPC/bulb.

Perform the Diagnostic Repair Verification after completing the repair.

«Instrument Cluster Replacement»(/chevrolet/express-g2500/2013-2013/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM and ICM replacement, programming, and setup.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Glow Plug Supply Voltage (1)	P0671	P0671	P0671
Glow Plug Supply Voltage (2)	P0672	P0672	P0672
Glow Plug Supply Voltage (3)	P0673	P0673	P0673
Glow Plug Supply Voltage (4)	P0674	P0674	P0674
Glow Plug Supply Voltage (5)	P0675	P0675	P0675
Glow Plug Supply Voltage (6)	P0676	P0676	P0676
Glow Plug Supply Voltage (7)	P0677	P0677	P0677
Glow Plug Supply Voltage (8)	P0678	P0678	P0678

The glow plug control module has the ability to perform internal checks for an open or a short to ground on each of the glow plug circuits. If the glow plug control module senses a problem in a glow plug circuit, the glow plug on the affected cylinder will be disabled and the glow plug control module will send an error message to the engine control module (ECM). If this condition exists, the appropriate DTC will set.

The ignition is ON.
DTCs P0671-P0678 run continuously.

The glow plug control module detects that the glow plug control circuit is open, shorted to ground, or has more than 1 ohms of resistance.

DTCs P0671-P0678 are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

If the battery is connected with the ignition ON, the glow plugs could be damaged without finding any circuit fault.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Ignition ON.
Using a scan tool observe the following parameters: All parameters should closely match each other. Cylinder 1 Glow Plug Cylinder 2 Glow Plug Cylinder 3 Glow Plug Cylinder 4 Glow Plug Cylinder 5 Glow Plug Cylinder 6 Glow Plug Cylinder 7 Glow Plug Cylinder 8 Glow Plug If all parameters do not closely match Refer to Circuit/System Testing. If all parameters closely match
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. If DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

Note. If a glow plug is replaced and the tip is missing or burned off, the cylinder head must be removed and all debris be cleaned out of the cylinder.

Ignition ON.
Glow plugs not commanded ON, verify that a test lamp does not illuminate between the appropriate Glow Plug Supply Voltage circuit terminal A and ground. If the test lamp illuminates Test the glow plug control circuit for a short to voltage. If the circuit tests normal, replace the K34 Glow Plug Control Module. If the test lamp does not illuminate
Command the Glow Plugs 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 does not turn ON and OFF Test the appropriate glow plug control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K34 Glow Plug Control Module. If the test lamp turns ON and OFF
Replace the appropriate E12 Glow Plug.

Ignition OFF.
Disconnect the harness connector of the appropriate glow plug.
Testing for less than 1 ohms between terminal A and ground. If the resistance is more than 1 ohms Replace the affected glow plug. If the resistance is less than 1 ohms
All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Glow Plug Replacement - Bank 1»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Glow Plug Replacement - Bank 2»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for glow plug control module replacement, programming, and setup.

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
Ignition ON, with a scan tool, command the glow plugs ON.
Clear the DTCs. If DTC P0671-P0678 is present, a condition with the system still exists.

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.

The ignition is ON or the engine is operating.
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.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each of the diagnostic category.

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

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

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-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If a DTC is not set
Verify there are no transmission control module DTCs set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If a DTC is not set
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.
Verify the DTC does not set. If the DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If the DTC does not set
All OK.

Perform the Diagnostic Repair Verification after completing the repair.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
DEF Pump Supply Voltage	P1044	P208A	P1044	P208B
DEF Pump Control	P208A	P208A	P1044, P208D	P208B
DEF Pump Low Reference		P208A		P208B

The ECM supplies system voltage to the reductant pump motor. The ECM controls the solenoid by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage. The ECM supplies a ground to the low reference circuit. As the duty-cycle increases, the output of the reductant pump increases.

Conditions for Running the DTCs

DTCs P204F, P20A1, or P2510 are not set
The battery voltage is greater than 11 V.
The engine speed is greater than 600 RPM for at least 10 s.
The DTCs 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 greater than 3 s.

DTCs P1043, P1044, P208A, and P208D are Type A DTCs.
The ECM inhibits the reductant system when DTC P1043, P208A, or P208D is set.
Service Emission System message is displayed on the driver information center (DIC).

DTCs P1043, P1044, P208A, and P208D are Type A DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Quality)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Level)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Emission Control)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Anti-Tampering)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy)
«Exhaust Aftertreatment System Description»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation)

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Ignition ON.
Verify DTC P204B, P204C, or P204D is not set. If one of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If none of the DTCs are set
Ignition ON.
Verify the Reductant System Leak Test turns ON when commanded ON with a scan tool.
Observe the scan tool Reductant Pump Control Circuit Status parameter. The parameter should display OK or Not Run. If OK or Not Run is not displayed Refer to Circuit/System Testing. If OK or Not Run is displayed
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.
Verify a DTC does not set. If any DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If no DTC sets
All OK.

Ignition OFF and all vehicle systems OFF, disconnect 24-way harness connector at the reductant tank. It may take up to 2 minutes for all vehicle systems to power down.
Test for less than 5 ohms between the low reference circuit terminal C8 and ground. If greater than 5 ohms 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
Ignition ON.
Test for B+ between the reductant pump motor supply voltage circuit terminal A6 and ground. If not within the specified range Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance in the supply voltage circuit to ground. If less than infinite resistance, repair the short to ground in the circuit. If infinite resistance Test for less than 2 ohms in the supply voltage 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 the specified range
Test for 2.5-4.5 V between the reductant pump supply motor control circuit terminal B6 and ground. If less than 2.5 V Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground in 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, replace the K20 Engine Control Module. If greater than 4.5 V 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 between 2.5-4.5 V
Connect a test lamp between the reductant pump supply motor control circuit terminal B6 and the reductant pump supply motor voltage circuit terminal A6.
Verify the test lamp illuminates or flashes when commanding the reductant pump to 80% with a scan tool. If the test lamp does not illuminate or flash Replace the K20 Engine Control Module. If the test lamp does illuminate or flash
Remove the reductant tank and verify the items listed below do not exist: Poor connection at the 24-way harness connector Open or shorted reductant pump supply voltage circuit Open or shorted reductant pump control circuit Open reductant pump low reference circuit If a condition is found Repair as necessary. If no condition is found
Replace the A38 Emission Reduction Fluid Supply Pump Module.

«Emission Reduction Fluid Supply Pump Module Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
Perform the scan tool Reductant System Reset procedure after replacing the A38 Emission Reduction Fluid Supply Pump Module.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
Clear the DTCs.
Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes.
Ignition ON.
Command the Reductant System Leak Test ON with a scan tool. Allow the pressure to build for at least 2 minutes. The first 60 s, the system performs a system purge.
Verify the Reductant Pressure sensor parameter is between 400-650 kPa (58-94 psi) with a scan tool. There should be no leaks in the system.
Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes.
Ignition ON.
Verify the Reductant lamp turns off if illuminated when commanding the Reductant System Data Reset ON with a scan tool. If the Reductant lamp does not turn OFF A condition with the system still exists If the Reductant lamp turns OFF
Perform the «Reductant System Malfunction Service Bay Test»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures__reductant-system-malfunction-service-bay-test) with a scan tool in order to clear the Service Emission System message, if displayed. If the Service Emission System message does not turn OFF A condition with the system still exists. If the Service Emission System message turns OFF
All OK.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
DEF Reverting Valve High Control	P20A2	P20A0	P1046, P2510, P204B	P208B
DEF Reverting Valve Low Control	P20A2	P20A0	P1046, P20A0, P20A3	P208B

The reductant purge valve controls the flow of diesel exhaust fluid (DEF). In the normally de-energized state, the purge valve directs reductant from the pump to the reductant injector. When the ignition is turned OFF, the engine control module (ECM) energizes both the reductant purge valve and reductant pump for about 30 to 45 seconds to purge the supply line of reductant. The ECM also commands the reductant injector to 100% to prevent vacuum from forming during the purge process. Purging prevents the reductant from freezing in the pump or supply line to the reductant injector. The ECM will set a DTC when an abnormal voltage condition on the purge valve circuit is detected.

The ECM provides battery voltage on the actuator high control circuit and ground on the actuator low control circuit. Both circuits are controlled through output drivers within the ECM. The ECM monitors the voltage on the circuits to detect a failure.

Battery voltage is greater than 11 V.
Engine speed is greater than 600 RPM for at least 10 s.
The DTCs run continuously when the above conditions are met.

P1046 or P20A3

When the solenoid is commanded ON, the ECM detects the commanded state of the driver and the actual state of the control circuits do not match for greater than 3 s.

P20A0 or P20A2

When the solenoid is commanded OFF, the ECM detects the commanded state of the driver and the actual state of the control circuits do not match for greater than 3 s.

DTC P20A0, P20A2 and P20A3 are Type A DTCs.
DTC P1046, is a Type B DTC.
The ECM inhibits the reductant system when DTC P20A0, P20A2, or P20A3 is set.
Service Emission System message is displayed on the driver information center (DIC).

DTC P20A0, P20A2 and P20A3 are Type A DTCs.
DTC P1046, is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Component View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Quality)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Level)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Emission Control)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Anti-Tampering)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy)
«Exhaust Aftertreatment System Description»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation)

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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.

Ignition ON, command the Reductant Purge Valve ON and OFF with a scan tool. You should hear an audible click. If an audible click is not heard Refer to Circuit/System Testing. If an audible click is heard
Ignition ON, command the Reductant Purge Valve ON and OFF with a scan tool while observing the Reductant Purge Valve Control Circuit Status parameter. Malfunction should not be displayed. If Malfunction is displayed Refer to Circuit/System Testing. If Malfunction is not displayed
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.
Verify a DTC does not set. If any DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If no DTC sets
All OK.

Ignition OFF, disconnect the 24-way harness connector at the reductant tank. Refer to «INLINE HARNESS CONNECTOR END VIEWS - INDEX»(/chevrolet/express-g2500/2013-2013/remont/body-electrical/#wiring-systems-and-power-management-inline-harness-connector-end-views-index) for connector identification.
Ignition ON, test for 2.5-4.5 V between the reductant reverting valve high control circuit terminal A7 and ground. If less than 2.5 V Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground in 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, replace the K20 Engine Control Module. If greater than 4.5 V 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 between 2.5-4.5 V
Command the Reductant Purge Valve ON and OFF with a scan tool. The DMM should transition from 2.5-4.5 V when commanded OFF to greater than 10 V, when commanded ON. If the circuit voltage does not correspond to the specified values Replace the K20 Engine Control Module If the circuit voltage corresponds to the specified values
Test for 2.5-4.5 V between the reductant reverting valve low control circuit terminal B7 and ground. If less than 2.5 V Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground in 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, replace the K20 Engine Control Module. If greater than 4.5 V 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 between 2.5-4.5 V
Command the Reductant Purge Valve ON and OFF with a scan tool. The DMM should transition from 2.5-4.5 V when commanded OFF to less than 2 V, when commanded ON. If the circuit voltage does not correspond to the specified values Replace the K20 Engine Control Module If the circuit voltage corresponds to the specified values
Remove the reductant tank and verify the items listed below do not exist: Poor connection at the 24-way harness connector. Open or shorted reductant reverting valve high control circuit. Open or shorted reductant reverting valve low control circuit. If a condition is found Repair as necessary. If no condition is found
Replace the Q62 Reductant Solenoid Purge Valve.

«Emission Reduction Fluid Supply Pump Module Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) for Q62 Reductant Solenoid Purge Valve
Perform the scan tool Reductant System Reset procedure after replacing the A38 Emission Reduction Fluid Supply Pump Module.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes.
Ignition ON, command the Reductant System Leak Test ON with a scan tool. Allow the pressure to build for at least 2 minutes. The first 60 s, the system performs a system purge. Observe the scan tool Reductant Pressure sensor parameter. The reading should be between 400-650 kPa (58-94 psi) and there should be no leaks in the system. If not within the specified range or a leak is found A condition with the system still exists If within the specified range and no leak is found
Clear the DTCs.
Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes.
Verify the reductant indicator lamp turns off when commanding the Reductant System Data Reset ON with a scan tool, if illuminated. If the reductant indicator lamp does not turn OFF A condition with the system still exists If the reductant indicator lamp turns OFF
Verify the Service Emission System message turns off, if displayed when commanding the «Reductant System Malfunction Service Bay Test»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures__reductant-system-malfunction-service-bay-test) ON with a scan tool. If the Service Emission System message does not turn OFF A condition with the system still exists If the Service Emission System message turns OFF
All OK.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
DEF Dosing Valve High Control	P1048, P2048	P2047	P1049	P202E
DEF Dosing Valve Low Control	P1048, P2048	P2047	P2047	P202E

The ECM supplies voltage to the reductant injector on the injector high control circuit. The ECM turns ON the reductant injector by grounding the low control circuit of the injector.

Engine is running.
Battery voltage is greater than 11 V.
ECM is commanding the reductant injector duty cycle greater than 0%.
Reductant Injection Inhibit Reason displays None.
The DTCs run continuously once 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 5 s.

DTCs P1048, P1049, P2047, P2048, and P2049 are Type A DTCs.
The ECM inhibits the reductant system when DTC P1048, P1049, P2048, or P2049 is set.
Service Emission System message is displayed on the driver information center (DIC).

DTCs P1048, P1049, P2047, P2048, and P2049 are Type A DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Component View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Quality)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Level)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Emission Control)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Anti-Tampering)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy)
«Exhaust Aftertreatment System Description»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation)

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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 34730-2C Injector Test Lamp

Engine idling, observe the DTC information with a scan tool. DTC P1043, P1044, P204B, P204C, P204D, P208A, P208B, P208C, or P208D should not be set. If one of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If none of the DTCs are set
Observe the scan tool Reductant Injector Control Circuit Status parameter. The parameter should display OK or Not Run. If OK or Not Run is not displayed Refer to Circuit/System Testing. If OK or Not Run is displayed
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.
Verify a DTC does not set. If any DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If no DTC sets
All OK.

Ignition OFF, disconnect the harness connector at the Q61 Emission Reduction Fluid Injector.
Ignition ON, test for B+ between DEF dosing valve high control circuit terminal 1 and ground. If not within the specified range Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance in the supply voltage circuit to ground. If less than infinite resistance, repair the short to ground in the circuit. If infinite resistance Test for less than 2 ohms in the supply voltage 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 the specified range
Ignition ON, test for 2.5-4.5 V between the DEF dosing valve low control circuit terminal 2 and ground. If less than 2.5 V Test for infinite resistance between the low control circuit and ground. If less than infinite resistance, repair the short to ground in the circuit. If infinite resistance Test for less than 2 ohms in the low 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 greater than 4.5 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Ignition ON. Test for less than 1 V between the low 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 between 2.5-4.5 V
Connect a J 34730-2C Injector Test Lamp between the DEF dosing valve high control circuit terminal 1 and DEF dosing valve low control circuit terminal 2.
Command the Reductant Injector to 80 percent with a scan tool. The test lamp should illuminate or flash when commanded to 80 percent. If the test lamp does not illuminate or flash Replace the K20 Engine Control Module. If the test lamp does illuminate or flash
Test or replace the Q61 Emission Reduction Fluid Injector.

Ignition OFF, disconnect the harness connector at the Q61 Emission Reduction Fluid Injector.
Test for 10-14 ohms between the DEF dosing valve high control circuit terminal 1 and the DEF dosing valve low control circuit terminal 2 of the Q61 Emission Reduction Fluid Injector. If not within the specified range Replace the Q61 Emission Reduction Fluid Injector. If within the specified range
Test for infinite resistance between each terminal and the Q61 Emission Reduction Fluid Injector housing. If not the specified value Replace the Q61 Emission Reduction Fluid Injector. If the specified value
All OK.

«Emission Reduction Fluid Injector Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
Perform the scan tool Reductant Injector Reset procedure after replacing the Q61 Emission Reduction Fluid Injector.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
Clear the DTCs.
Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes.
Ignition ON, perform the Reductant System Data Reset with a scan tool in order to clear the reductant indicator lamp, if illuminated. If the reductant indicator lamp does not turn OFF A condition with the system still exists. If the reductant indicator lamp turns OFF
Perform the «Reductant System Malfunction Service Bay Test»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures__reductant-system-malfunction-service-bay-test) with a scan tool in order to clear the Service Emission System message, if displayed. If the Service Emission System message does not turn OFF A condition with the system still exists. If the Service Emission System message turns OFF
All OK.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Fuel Filter Pressure Switch Signal		P1082	P1082
Signal Ground		P1082

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition ON Parameter Normal Range: Normal
Fuel Filter Pressure Switch Signal	High Pressure	Normal	Normal

Fuel Filter Pressure Switch

The fuel filter pressure switch is a normally closed switch located near the fuel filter housing. If fuel supply line vacuum is greater than 14 in Hg the switch will open. The engine control module (ECM) monitors the system in after-run for an open circuit.

ECM monitors the circuit 30 s into the after-run mode.

The ECM detects an open or short to voltage in the Fuel Filter Pressure Switch Signal circuit.
The above condition is present for greater than 3 s.

DTC P1082 is a Type C DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

A restricted, kinked, or damaged fuel supply line may cause this DTC to set.
Contaminated or improper fuel may cause this DTC to set. Refer to «Fuel System Specifications»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications) , and «Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures__contaminants-in-fuel-diagnosis) .
A restricted or contaminated fuel filter may cause this DTC to set.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

CH-48027 Digital Pressure Gauge

Ignition ON.
Verify the scan tool Fuel Filter Pressure Switch parameter displays Normal. If parameter does not display Normal Refer to Circuit/System Testing. If parameter displays Normal
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. If DTC resets Refer to Circuit/System Testing. If DTC does not reset
All OK.

Install the CH-48027 digital pressure gauge to the fuel system service port on the right front side of the engine.
Verify the CH-48027 digital pressure gauge displays 0 in Hg. If the value is not 0 in Hg. Refer to «Fuel System Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) . If the value is 0 in Hg.
Ignition OFF.
Disconnect the harness connector at the B181 fuel filter pressure switch.
Test for less than 10 ohms between the B181 fuel filter pressure switch terminal A and terminal B. If greater than 10 ohms Replace the B181 fuel filter pressure switch. If less than 10 ohms
Test for less than 5 ohms between the low reference circuit terminal B and ground. If greater than 5 ohms Repair the open or high resistance in the low reference circuit. If less than 5 ohms
Ignition ON.
Verify the scan tool Fuel Pressure Switch parameter displays High Pressure. If parameter does not display High Pressure Test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the K20 engine control module. If parameter displays High Pressure
Install a 3 A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool Fuel Filer Pressure Switch parameter displays Normal. If parameter does not display High Pressure Test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 engine control module. If parameter displays High Pressure
All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Engine Fuel Vacuum Switch Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup.

The Engine Control Module (ECM) monitors the fuel rail pressure deviation when the vehicle is in a speed deceleration condition and the fuel command request is at zero. The fuel rail pressure deviation needs to exceed 5 MPa while in fuel cutoff for approximately 80 seconds of cumulative deceleration, this may take multiple drive cycles.

Ambient air temperature is above -7°C (19°F).
Fuel temperature is between 0-80°C (32-176°F).
Fuel system status is in fuel shut off mode during deceleration.
Engine temperature is greater the 50°C (122°F).
Engine speed is between 950-1850 RPM.
Accelerator pedal position is less than .05 percent.
Boost pressure is between 75 and 150 kPa.
Vehicle speed greater than 0 mph.
The DTC runs continuous when the above conditions exist.

Rail pressure deviation is greater than 5 MPa (725 PSI) while in fuel cutoff for approximately 80 seconds of cumulative deceleration.

DTC P1089 is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This Diagnostic parameter is stored in the ECM over a period of time. Time to set this DTC may take several drive cycles.
A restricted, kinked, or damaged fuel supply line including restricted fuel filter may cause this DTC to set.
Water or contaminated fuel may cause this DTC to intermittently set. Refer to «Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures__contaminants-in-fuel-diagnosis) .
When ambient temperatures are below 0°C (32°F), the fuel tank pickup screen may be iced over from water in the fuel tank.
When power enhancing devices have been attached to the fuel rail pressure sensor circuits, this DTC may set and adversely affect the fuel system components.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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.

Ignition ON, observe the DTC information with a scan tool. Verify there are no other DTCs set. If another DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If another DTC is not set
Verify the proper fuel is used. Refer to «Fuel System Specifications»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications) , and «Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures__contaminants-in-fuel-diagnosis) .
Verify there are no aftermarket performance enhancing devices installed on the vehicle.
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.

Perform the Diagnostic Repair Verification after completing the repair.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Hydrocarbon Injector High Control or Exhaust Aftertreatment Fuel Injector High Control	P10CD	P20CB	P10CE	P10CC, P20CB
Hydrocarbon Injector Low Control or Exhaust Aftertreatment Fuel Injector Low Control	P20CD	P20CB	P20CE	P10CC, P20CB

The Engine Control Module (ECM) supplies power and ground to the high and low control circuits of the Exhaust Aftertreatment Fuel Injector or Indirect Fuel Injector. When the ECM detects a fault on either of the injector circuits it sets a DTC.

Battery Voltage is greater than 11 V.
Engine speed is greater than 600 RPM.

DTC P10CC

The ECM detects a short in the Exhaust Aftertreatment Fuel Injector control circuit.
The condition exists for more than 0.5 s.

DTC P20CB

The ECM detects an error in the Exhaust Aftertreatment Fuel Injector circuits.
The condition exists for more than 3 s.

DTC P10CC and P20CB are a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Engine running.
Observe the following control circuit parameters with a scan tool: Each parameter should display OK or Not Run. Exhaust Aftertreatment Fuel Injector High Control Circuit High Voltage Test Status Exhaust Aftertreatment Fuel Injector High Control Circuit Low Voltage Test Status Exhaust Aftertreatment Fuel Injector Control Circuit High Voltage Test Status Exhaust Aftertreatment Fuel Injector Control Circuit Low Voltage Test Status Exhaust Aftertreatment Fuel Injector Control Circuit Shorted Test Status Exhaust Aftertreatment Fuel Injector Control Circuit Open Test Status If any parameter does not display OK or Not Run Refer to Circuit/System Testing. If all the parameters display OK or Not Run
Ignition ON.
Command the Exh. Aftertreatment Fuel Injector to 50 %. Verify an audible click at the Q57 Exhaust Aftertreatment Fuel Injector. If no audible click is heard Refer to Circuit/System Testing. If audible click is heard
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. If DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

Note. Poor fuel supply could over heat and damage the Exhaust Aftertreatment Fuel Injector.

Ignition OFF.
Disconnect the harness connector at the Q57 Exhaust Aftertreatment Fuel Injector.
Ignition ON.
Command the Exhaust Aftertreatment Fuel Injector to 90 % with a scan tool, verify a test lamp flashes ON and OFF between the high control circuit terminal 2 and ground. If the test lamp remains illuminated Test the high control circuit for a short to B+. If the circuit tests normal, replace the K20 Engine Control Module. If the test lamp does not flash ON and OFF Test the high control circuit for an open/high resistance or short to ground, If the circuit tests normal, replace the K20 Engine Control Module. If the test lamp flashes ON and OFF
Command the Exhaust Aftertreatment Fuel Injector to 90 % with a scan tool, verify a test lamp flashes ON and OFF between the high control circuit terminal 2 and the low control circuit terminal 1. If the test lamp does not flash ON and OFF Test the low control circuit for an open/high resistance or short to B+, If the circuit tests normal, K20 Engine Control Module. If the test lamp flashes ON and OFF
Replace the Q57 Exhaust Aftertreatment Fuel Injector.

Ignition OFF.
Disconnect the harness connector at the Q57 Exhaust Aftertreatment Fuel Injector.
Test for 10.7-13.3 ohms between the control terminal 1 and the control terminal 2 of the Exhaust Aftertreatment Fuel Injector. If not within 10.7-13.3 ohms Replace the Q57 Exhaust Aftertreatment Fuel Injector. If within 10.7-13.3 ohms
Test for infinite resistance between each terminal and the Q57 Exhaust Aftertreatment Fuel Injector housing/case. If not infinite resistance Replace the Q57 Exhaust Aftertreatment Fuel Injector. If infinite resistance
All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Indirect Fuel Injector Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__indirect-fuel-injector-replacement) for Exhaust Aftertreatment Fuel Injector replacement.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Hydrocarbon Injector High Control or Exhaust Aftertreatment Fuel Injector High Control	P10CD	P20CB	P10CE	P10CC. P20CB
Hydrocarbon Injector Low Control or Exhaust Aftertreatment Fuel Injector Low Control	P20CD	P20CB	P20CE	P10CC, P20CB

The engine control module (ECM) supplies power and ground to the high and low control circuits of the exhaust aftertreatment fuel injector or indirect fuel injector. When the ECM detects a fault on either of the exhaust aftertreatment fuel injector circuits it sets a DTC.

Battery Voltage is greater than 11 V.
Engine speed is greater than 600 RPM.

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match.
The condition exists for more than 3 s.

DTC P10CC, P20CB, P20CD and P20CE are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Engine running.
Observe the following control circuit parameters with a scan tool: Each parameter should display OK or Not Run. Exhaust Aftertreatment Fuel Injector High Control Circuit High Voltage Test Status Exhaust Aftertreatment Fuel Injector High Control Circuit Low Voltage Test Status Exhaust Aftertreatment Fuel Injector Control Circuit High Voltage Test Status Exhaust Aftertreatment Fuel Injector Control Circuit Low Voltage Test Status Exhaust Aftertreatment Fuel Injector Control Circuit Shorted Test Status Exhaust Aftertreatment Fuel Injector Control Circuit Open Test Status If any parameter does not display OK or Not Run Refer to Circuit/System Testing. If all the parameters display OK or Not Run
Ignition ON.
Command the Exh. Aftertreatment Fuel Injector to 50 %. Verify an audible click at the Q57 Exhaust Aftertreatment Fuel Injector. If no audible click is heard Refer to Circuit/System Testing. If audible click is heard
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. If DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

Note. Poor fuel supply could over heat and damage the exhaust aftertreatment fuel injector.

Ignition OFF.
Disconnect the harness connector at the Q57 Exhaust Aftertreatment Fuel Injector.
Ignition ON.
Command the Exhaust Aftertreatment Fuel Injector to 90 % with a scan tool, verify a test lamp flashes ON and OFF between the high control circuit terminal 2 and ground. If the test lamp remains illuminated Test the high control circuit for a short to B+. If the circuit tests normal, replace the K20 Engine Control Module. If the test lamp does not flash ON and OFF Test the high control circuit for an open/high resistance or short to ground, If the circuit tests normal, replace the K20 Engine Control Module. If the test lamp flashes ON and OFF
Command the Exhaust Aftertreatment Fuel Injector to 90 % with a scan tool, verify a test lamp flashes ON and OFF between the high control circuit terminal 2 and the low control circuit terminal 1. If the test lamp does not flash ON and OFF Test the low control circuit for an open/high resistance or short to B+, If the circuit tests normal, replace the K20 Engine Control Module. If the test lamp flashes ON and OFF
Refer to Component Testing.

Static Testing

Ignition OFF.
Disconnect the harness connector at the Q57 Exhaust Aftertreatment Fuel Injector.
Test for 10.7-13.3 ohms between the control terminal 1 and the control terminal 2 of the Exhaust Aftertreatment Fuel Injector. If not within 10.7-13.3 ohms Replace the Q57 Exhaust Aftertreatment Fuel Injector. If within 10.7-13.3 ohms
Test for infinite resistance between each terminal and the Q57 Exhaust Aftertreatment Fuel Injector housing/case. If not infinite resistance Replace the Q57 Exhaust Aftertreatment Fuel Injector. If infinite resistance
Perform Dynamic Testing.

Dynamic Testing

Verify the flow rate of the Q57 Exhaust Aftertreatment Fuel Injector, refer to «Exhaust Aftertreatment Fuel Injector Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) . If not within specified value Replace the Q57 Exhaust Aftertreatment Fuel Injector. If within the specified value
All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Indirect Fuel Injector Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__indirect-fuel-injector-replacement) for Exhaust Aftertreatment Fuel Injector replacement.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Signal	P007C	P007D	P007D*	P007D, P10CF
Low Reference		P007D	P007D*
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

Charge Air Cooler (CAC) Temperature Sensor

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Signal	P00EA	P00EB	P00EB*	P00EB, P0101
Low Reference		P00EB	P00EB*
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

IAT Sensor 3

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition ON or Engine Running Parameter Normal Range: -39 to +198°C (-38 to +388°F)
Signal	199°C (390°F)	40°C (-40°F)	40°C (-40°F)*
Low Reference		40°C (-40°F)	40°C (-40°F)*
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

CAC Temperature Sensor

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition ON or Engine Running Parameter Normal Range: -39 to +213°C (-38 to +415°F)
Signal	215°C (419°F)	40°C (-40°F)	40°C (-40°F)*
Low Reference		40°C (-40°F)	40°C (-40°F)*
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

IAT Sensor 3

The charge air cooler (CAC) temperature sensor and intake air temperature (IAT) sensor 3 are variable resistors. The IAT sensor 3 is located in the CAC inlet duct. The CAC temperature sensor is located in the CAC outlet duct before the throttle body assembly. The engine control module (ECM) supplies 5 V to the signal circuits, and a ground for each sensor's low reference circuit. The ECM monitors the CAC temperature sensor and the IAT sensor 3 circuits in order to calculate the temperature of the fuel air. The ECM monitors the CAC sensor and IAT sensor 3 signal for excessively high or low voltages, or for a voltage that is not in correlation with the other sensor's start up signal.

Condition 1

Ignition has been OFF for 8 hours or more.
The engine is running.
The Ambient temperature is warmer than -60°C (-76°F).

Condition 2

Ignition has been OFF for 8 hours or more.
The engine is running.
The Ambient temperature is warmer than -60°C (-76°F).
In the first 60 s of engine run time, the ECM determines the block heater is OFF. AND
In the first 10 minutes of engine run time, the vehicle speed as been at least 24 Km/h (15 mph) for at least 5 minutes and the ECM determines there is no sun load.

This DTC runs once per key cycle when the conditions in 1 or 2 are met.

Condition 1

The ECM determines the absolute temperature difference between the CAC Temperature Sensor signal and the IAT Sensor 3 signal is more than 100°C (180°F) at start up.

Condition 2

The ECM determines the absolute temperature difference between the CAC Temperature Sensor signal and the IAT Sensor 3 signal is more than 35°C (63°F), but less than or equal to 100°C (180°F) after 10 minutes of engine run time.
The ECM determines the block heater is OFF.
The ECM determines there is no sun load.

DTC P10CF is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The CAC Temperature Sensor is located after the outlet from the CAC. The CAC Temperature Sensor is also known as the CAC Outlet Temperature Sensor (Charge Air Outlet Duct).
The IAT Sensor 3 is located before the inlet to the CAC. The IAT Sensor 3 is also known as the CAC Inlet Temperature Sensor (Turbocharger).
Skewed temperature sensors may cause this DTC to set.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Note. To minimize the effects of residual engine heat and sensor internal heating elements, perform Steps 1 and 2 of this verification procedure only if the ignition has been OFF for 8 hours or more. The vehicle sitting in direct sun light or having the block heater ON will skew the results.

Ignition ON.
Verify the following scan tool parameters are within 15°C (27°F) of each other. CAC Temperature Sensor IAT Sensor 3 If not within 15°C (27°F) Refer to Circuit System Testing. If within 15°C (27°F)
Engine idling.
Verify the following scan tool parameters are within the specified ranges. IAT Sensor 3; -39 to +213°C (-38 to +415°F) CAC Temperature Sensor;-39 to +198°C (-38 to +388°F) If not within the specified ranges Refer to Circuit System Testing. If within the specified ranges
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.
Verify a DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
All OK.

Note. You must perform the Circuit/System Verification before proceeding with the Circuit/System Testing. You must perform the Diagnostic Repair Verification after completing the Circuit/System Testing.

Ignition OFF, disconnect the harness connector at the B193A Charge Air Cooler Temperature sensor.
Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 2 ohms between the B193A Charge Air Cooler Temperature sensor low reference circuit terminal 2 and ground. If 2 ohms or greater Ignition OFF, disconnect the X3 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 or high resistance in the circuit. If less than 2 ohms replace the K20 Engine Control Module. If less than 2 ohms
Test for 4.8-5.2 V between the signal circuit terminal 1 and ground. If less than 4.8 V Ignition OFF, disconnect the X3 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 NOTE: If the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged. Ignition OFF, disconnect the X3 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
Ignition OFF, disconnect the harness connector at the Intake Air Temperature sensor 3.
Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 2 ohms between the Intake Air Temperature sensor 3 low reference circuit terminal 2 and ground. If 2 ohms or greater Ignition OFF, disconnect the X3 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 or high resistance in the circuit. If less than 2 ohms replace the K20 Engine Control Module. If less than 2 ohms
Test for 4.8-5.2 V between the signal circuit terminal B and ground. If less than 4.8 V Ignition OFF, disconnect the X3 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 NOTE: If the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged. Ignition OFF, disconnect the X3 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
If all circuits test normal, test or replace the appropriate temperature sensor.

Test the appropriate temperature sensor by varying the sensor temperature while monitoring the air temperature with a thermometer. Compare the readings with the appropriate scan tool parameter. The values should be within 5%. If not within the specified range, replace the appropriate sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Charge Air Temperature Sensor Replacement (Turbocharger)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) , «Charge Air Temperature Sensor Replacement (Outlet Pipe)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) (Turbocharger) for Intake Air Temperature Sensor 3; Charge Air Cooler Inlet Temperature Sensor Replacement.
«Charge Air Temperature Sensor Replacement (Turbocharger)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) , «Charge Air Temperature Sensor Replacement (Outlet Pipe)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) (Charge Air Outlet Duct) for Charge Air Cooler Temperature Sensor; Charge Air Cooler Outlet Temperature Sensor Replacement
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Engine Control Module replacement, programming, and setup

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Engine Running Parameter Normal Range: -29 to 999°C (0°F to 1830°F)
Signal	40°C (-40°F)	1000°C (1832°F)	1000°C (1832°F)
Low Reference		1000°C (1832°F)	1000°C (1832°F)

EGT Sensor 2

The exhaust gas temperature sensors are variable resistors that measure the temperature of the exhaust gas at the inlet and outlet of the diesel oxidation catalyst as well as the inlet and outlet of the Diesel Particulate Filter (DPF). The Engine Control Module (ECM) supplies a bias 5-volt signal to the exhaust gas temperature sensor signal circuit, and supplies a ground to the low reference circuit. The exhaust gas temperature information is used by the ECM during the particulate filter cleaning process.

The selective catalytic reduction (SCR) system reduces oxides of nitrogen (NOx) emissions by injecting a metered amount of diesel exhaust fluid (DEF) or reductant into the exhaust gas stream entering the SCR catalyst. Within the SCR catalyst, the reductant reacts with the NOx to form nitrogen, carbon dioxide, and water vapor. Upstream and downstream NOx sensors provide the engine control module (ECM) with engine-out and tailpipe-out NOx levels. The ECM varies the amount of reductant added by varying the reductant injector duty-cycle in response to changes in engine-out NOx levels. The ECM supplies voltage to the reductant injector on the injector high control circuit. The ECM turns ON the reductant injector by grounding the low control circuit of the injector. The reductant injector temperature is modeled based on internal injector resistance of the injector coil and is used to monitor the temperature of the injector to prevent damage.

Ignition has been OFF for greater than 8 hours.
Reductant dosing has not been requested by the ECM.
Engine is running for less than 10 s.
Ambient air temperature is greater than -60°C (-76°F)
Battery voltage is greater than 11 V.
DTC P10D0 runs once per key cycle when the above conditions are met.

An implausible injector coil temperature is detected by comparing the coil temperature with the EGT sensor 2 as a reference temperature. This is done after a sufficient engine off time and before the coil has been energized. If the absolute difference between the coil and reference temperature is greater than a calibrated threshold, then P10D0 is set.

DTC P10D0 is a Type B DTC

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

A slight to moderate resistance in either the signal or low reference circuits, can widen the spread between the exhaust gas temperature sensors and the reductant injector, and cause the DTC to set.

Schematic Reference

Connector End View Reference

Component View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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 25070 Heat Gun 500-750°F

Ignition OFF for greater than 8 hours.
Ignition ON.
Verify DTCs P113A, P2080, P2084, P20E2, P242B or P246F are not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) If none of the DTCs are set
Verify the scan tool Exhaust Gas Temperature Sensor 2 parameter is within 30°C (54°F) of the ambient temperature. If not within 30°C (54°F) Replace the B131 EGT sensor 2. If within 30°C (54°F)
Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the Q61 Emission Reduction Fluid Injector. It may take up to 2 minutes for all vehicle systems to power down.
Verify the Q61 Emission Reduction Fluid Injector resistance is within the range specified in the «Temperature Versus Resistance (Fuel Temperature Sensor)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-fuel-temperature-sensor) , «Temperature Versus Resistance (ECT Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-ect-sensors) , «Temperature Versus Resistance (IAT Sensor 1)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-iat-sensor-1) , «Temperature Versus Resistance (IAT Sensor 2)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-iat-sensor-2) , «Temperature Versus Resistance (EGT Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-egt-sensors) , «Temperature Versus Resistance (EGR Temperature Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-egr-temperature-sensors) , «Temperature Versus Resistance (Emission Reduction Fluid Injector)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-emission-reduction-fluid) , table. Measure and record the resistance of the Q61 Emission Reduction Fluid Injector between the low reference circuit terminal 1 and the control circuit terminal 2 and compare to the measurements to the «Temperature Versus Resistance (Fuel Temperature Sensor)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-fuel-temperature-sensor) , «Temperature Versus Resistance (ECT Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-ect-sensors) , «Temperature Versus Resistance (IAT Sensor 1)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-iat-sensor-1) , «Temperature Versus Resistance (IAT Sensor 2)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-iat-sensor-2) , «Temperature Versus Resistance (EGT Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-egt-sensors) , «Temperature Versus Resistance (EGR Temperature Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-egr-temperature-sensors) , «Temperature Versus Resistance (Emission Reduction Fluid Injector)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-emission-reduction-fluid) chart. If not within the specified range Replace the Q61 Emission Reduction Fluid Injector If within the specified range
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.
Verify a DTC does not set. If any DTCs set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) If no DTCs set
All OK.

Perform the Diagnostic Repair Verification after completing the repair.

«Exhaust Temperature Sensor Replacement - Position 2»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Emission Reduction Fluid Injector Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Fuel Temperature Sensor 1 Signal	P0182	P0183, P111F	P0183	P111F
Fuel Temperature Sensor 2 Signal	P0187	P0188, P111F	P0188	P111F
Fuel Temperature Sensor 1 Low Reference		P0183		P111F
Fuel Temperature Sensor 2 Low Reference		P0188		P111F

The fuel temperature sensor is a thermistor. The engine control module (ECM) supplies the fuel temperature sensor a bias voltage of 5 volts on the signal circuit and also provides a low reference circuit to the sensor. When the fuel temperature sensor is cold, the resistance is high. The fuel temperature sensor signal voltage remains near the 5 volt bias voltage cold and decreases as the sensor warms. The ECM compares the fuel temperature between fuel temperature sensor 1 and fuel temperature sensor 2 at engine start up. If the difference is above the calibrated threshold, the fault will be detected unless a block heater was responsible for the deviation.

Engine temperature is greater than -60° C (-76° F).
Engine speed is between 600-850 RPM.
Engine off time is greater than 8 hours.
DTC P111F runs once per trip within the above enabling conditions.

A fault is detected when fuel temperature sensors 1 and 2 are compared at start up and if the difference exceeds the allowed limit for greater than 0.2 seconds.

DTC P111F is a Type B DTC.

DTC P111F is a Type B DTC

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Fuel Temperature Sensor 1 is located on the back side of the fuel injection pump.
Fuel Temperature Sensor 2 also referred to as the Fuel Rail Temperature Sensor is located in the fuel return line near the quick-connect fittings.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)
«Temperature Versus Resistance (Fuel Temperature Sensor)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-fuel-temperature-sensor) , «Temperature Versus Resistance (ECT Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-ect-sensors) , «Temperature Versus Resistance (IAT Sensor 1)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-iat-sensor-1) , «Temperature Versus Resistance (IAT Sensor 2)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-iat-sensor-2) , «Temperature Versus Resistance (EGT Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-egt-sensors) , «Temperature Versus Resistance (EGR Temperature Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-egr-temperature-sensors) , «Temperature Versus Resistance (Emission Reduction Fluid Injector)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-emission-reduction-fluid)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition OFF for greater than 8 hours.
Ignition ON, block heater not active.
Verify DTCs P0182, P0183, P0187, or P0188 are not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If none of the DTCs are set
Verify the scan tool Fuel Temperature Sensor and Fuel Rail Temperature Sensor parameters are within 20°C (68°F) of ambient temperature. If Fuel Temperature Sensor 1 is not within 20°C (68°F) Refer to Fuel Temperature Sensor 1 in Circuit/system testing. If Fuel Rail Temperature Sensor is not within 20°C (68°F) Refer to Fuel Temperature Sensor 2 in Circuit/system testing. If within 20°C (68°F)
All OK.

Fuel Temperature Sensor 1

Ignition OFF.
Disconnect the 12-way harness connector at the engine harness jumper. Refer to «INLINE HARNESS CONNECTOR END VIEWS - INDEX»(/chevrolet/express-g2500/2013-2013/remont/body-electrical/#wiring-systems-and-power-management-inline-harness-connector-end-views-index) .
Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 3 and ground. If less than 4.8 V Test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module. If greater than 5.2 V Test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module. If between 4.8-5.2 V
Install a 3 A fused jumper wire between the signal circuit terminal 3 and the low reference circuit terminal 4. Verify the scan tool Fuel Temperature Sensor parameter is greater than 120°C (248°F). If less than 120°C (248°F) Test the low reference circuit for an open, high resistance or short to voltage. If the circuit tests normal, replace the K20 Engine Control Module. If greater than 120°C (248°F)
Disconnect the harness connector at the B48 Fuel Temperature Sensor. Test, inspect and repair the items below. If all items test normal, replace the B48 Fuel Temperature Sensor. Poor connection at the B48 Fuel Temperature Sensor. Open, high resistance or shorted fuel temperature sensor signal circuit. Open, high resistance or shorted fuel temperature sensor low reference circuit.

Fuel Temperature Sensor 2

Ignition OFF, disconnect the harness connector at the B132 Fuel Rail Temperature Sensor.
Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 1 and ground. If less than 4.8 V Test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module. If greater than 5.2 V Test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the scan tool Fuel Rail Temperature Sensor parameter is greater than 120°C (248°F). If less than 120°C (248°F) Test the low reference circuit for an open, high resistance or short to voltage. If the circuit tests normal, replace the K20 Engine Control Module. If greater than 120°C (248°F)
If all circuits test normal, test or replace the B132 Fuel Rail Temperature Sensor.

Measure and record the resistance of the fuel temperature sensor at various temperatures and compare those measurements to the Temperature vs. Resistance table. Refer to Temperature Versus Resistance (Fuel Temperature Sensor) , Temperature Versus Resistance (ECT Sensors) , Temperature Versus Resistance (IAT Sensor 1) , Temperature Versus Resistance (IAT Sensor 2) , Temperature Versus Resistance (EGT Sensors) , Temperature Versus Resistance (EGR Temperature Sensors) , Temperature Versus Resistance (Emission Reduction Fluid Injector) .

Perform the Diagnostic Repair Verification after completing the repair.

«Fuel Temperature Sensor Replacement (Fuel Return Rail)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) , «Fuel Temperature Sensor Replacement (Injection Pump)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup.

Circuit	Short to Ground	Open	High Resistance	Short to Voltage	Signal Performance
Exhaust Gas Temperature Sensor 1 Signal	P0545	P0546	P20E2, P2080	P0546*	P20E2, P2080
Exhaust Gas Temperature Sensor 1 Low Reference		P0546	P20E2, P2080	P0546*	P20E2, P2080
Exhaust Gas Temperature Sensor 2 Signal	P2032	P2033	P20E2, P2084	P2033*	P20E2, P2084
Exhaust Gas Temperature Sensor 2 Low Reference		P2033	P20E2, P2084	P2033*	P20E2, P2084
Exhaust Gas Temperature Sensor 3 Signal	P242C	P242D	P113A, P242B	P242D*	P113A, P242B
Exhaust Gas Temperature Sensor 3 Low Reference		P242D	P113A, P242B	P242D*	P113A, P242B
Exhaust Gas Temperature Sensor 4 Signal	P2470	P2471	P113A, P246F	P2471*	P113A, P246F
Exhaust Gas Temperature Sensor 4 Low Reference		P2471	P113A, P246F	P2471*	P113A, P246F
* Internal ECM or Sensor damage may occur if the circuit is shorted to B+

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Operating Conditions: Engine Running Parameter Normal Range: -39-999°C (-38-1,830°F)
Exhaust Gas Temperature Sensor 1-4 Signal	40°C (-40°F)	1,000°C (1,832°F)	1,000°C (1,832°F)
Exhaust Gas Temperature Sensor 1-4 Low Reference		1,000°C (1,832°F)	1,000°C (1,832°F)

EGT Sensor 1-4

The following table illustrates the relationship between the temperature of the exhaust gas, and the resistance and voltage of the exhaust gas temperature sensor.

Temperature	Resistance	Voltage
Low	Low	Low
High	High	High

P113A

DTC P0112, P0113, P242C, P242D, P2470, or P2471 is not set.
Ignition has been OFF for greater than 8 hours.
Engine is running.
Ambient air temperature is greater than -60°C (-76°F).
The DTC runs once per key cycle when the above conditions are met.

P20E2

Condition 1

DTC P0016, P0112, P0113, P0335, P0336, P0340, P0341, P0545, P0546, P2032, or P2033 is not set.
Ignition has been OFF for greater than 8 hours.
Engine is running.
Ambient air temperature is greater than -60°C (-76°F).

Condition 2

DTC P0016, P0112, P0113, P0335, P0336, P0340, P0341, P0545, P0546, P2032, or P2033 is not set.
Ignition has been OFF for greater than 8 hours.
Engine is running.
Ambient air temperature is greater than -60°C (-76°F).
In the first 60 s of engine run time, the ECM determines that the engine block heater is OFF.

DTC P02E0 runs once per key cycle when condition 1 or condition 2 above is met.

P113A

The ECM detects, at engine start, that a temperature difference of greater than 30°C (54°F), exists between exhaust gas temperature sensor 3 and exhaust gas temperature sensor 4.

P20E2

Condition 1

The ECM detects, at engine start, that a temperature difference of greater than 100°C (180°F), exists between exhaust gas temperature sensor 1 and exhaust gas temperature sensor 2.

Condition 2

The ECM determines the temperature difference between the exhaust gas temperature sensor 1 and exhaust gas temperature sensor 2 is greater than 30°C (54°F), but less than or equal to 100°C (180°F), after 60 s of engine run time.

DTCs P113A and P20E2 are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

A slight to moderate resistance in either the signal or low reference circuits, can widen the spread between the exhaust gas temperature sensors, and cause the DTCs to set.

Schematic Reference

Connector End View Reference

Component View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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 25070 Heat Gun 500-750°F

Ignition OFF for greater than 8 hours.
Observe the scan tool Exhaust Gas Temperature Sensor 1-4 parameters and compare it to the ambient temperature. The reading for EGT 1-4 should be within 30°C (54°F) of the ambient temperature. If not within the specified range Refer to Circuit/System Testing. If within the specified range
Ignition ON
Observe the scan tool Exhaust Gas Temperature Sensor 1-4 parameters. The reading should be between -40-999°C (-40-1,830°F) depending on the current ambient temperature and the vehicle operating conditions. If not within the specified range Refer to Circuit/System Testing. If within the specified range
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.
Verify a DTC does not set If any DTCs set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If no DTCs set
All OK

Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate B131 Exhaust Gas Temperature sensor. It may take up to 2 minutes for all vehicle systems to power down.
Test for less than 5 ohms between the low reference circuit terminal B 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
Ignition ON.
Verify the scan tool Exhaust Gas Temperature sensor parameter is greater than 998°C (1828°F). If 998°C (1828°F) or less Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit terminal A 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 greater than 998°C (1828°F)
Install a 3 A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B.
Verify the scan tool Exhaust Gas Temperature parameter is less than -35°C (-31°F). If -35°C (-31°F) 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 Ignition OFF 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 less than -35°C (-31°F)
Test or replace the B131 Exhaust Gas Temperature sensor.

Ignition OFF, remove the affected B131 Exhaust Gas Temperature sensor while leaving the harness connector connected.
Measure and record the resistance of the B131 Exhaust Gas Temperature sensor and compare the measurements to the «Temperature Versus Resistance (Fuel Temperature Sensor)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-fuel-temperature-sensor) , «Temperature Versus Resistance (ECT Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-ect-sensors) , «Temperature Versus Resistance (IAT Sensor 1)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-iat-sensor-1) , «Temperature Versus Resistance (IAT Sensor 2)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-iat-sensor-2) , «Temperature Versus Resistance (EGT Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-egt-sensors) , «Temperature Versus Resistance (EGR Temperature Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-egr-temperature-sensors) , «Temperature Versus Resistance (Emission Reduction Fluid Injector)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-emission-reduction-fluid) chart. If not within the specified range Replace the B131 Exhaust Gas Temperature sensor. If within the specified range
All OK

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Exhaust Temperature Sensor Replacement - Position 1»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Exhaust Temperature Sensor Replacement - Position 2»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Exhaust Temperature Sensor Replacement - Position 3»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Exhaust Temperature Sensor Replacement - Position 4»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming and setup.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
NOx Sensor Ignition Voltage	U029D, U029E, P220A, P220B	U029D, U029E	U029D, U029E, P220A, P220B
High Speed GMLAN Serial Data (+)	U0074, P205D	U010E, P205D	U0074, P205D
High Speed GMLAN Serial Data (-)	U029D, U029E, U010E, P205D	U010E, P205D	U010E, P205D
NOx Sensor Ground		U029D, U029E

The reductant system uses two nitrogen oxide (NOx) sensors to monitor the amount of NOx in the engine's exhaust gas. The first sensor is located at the outlet of the turbocharger and monitors the engine out NOx level. The second NOx sensor is located between the selective catalytic reduction (SCR) and the diesel particulate filter (DPF) and monitors NOx levels downstream of the SCR. The second NOx sensor also provides the engine control module (ECM) with information on the exhaust oxygen level during DPF regeneration.

Each NOx sensor contains a sensing cell, a pumping cell, and a heater. A sample of exhaust gas passes through a diffusion gap between the sensing cell and the pumping cell. The NOx sensor maintains a constant reference voltage across the sensing cell. An electronic circuit within sensor controls the pump current through the pumping cell in order to maintain a constant voltage in the sensing cell. The amount of current required to maintain the reference voltage in the sensing cell is proportional to the concentration of NOx in the exhaust.

The ECM varies the amount of diesel exhaust fluid (DEF) or reductant added by varying the reductant injector duty cycle in response to changes in engine exhaust out NOx levels.

The smart NOx sensors consist of two components, the NOx module and the NOx sensor element that are serviced as a unit. A circuit or performance condition with a NOx sensor is detected by the NOx sensor module. The smart NOx sensor module communicates the condition to the ECM over the serial data line. The ECM sets a DTC when a serial data message is received from the NOx sensor module.

DTCs P0101, P0171, P0172, P0234, P026C, P026D, P0299, P0401, P0402, P0480, P0483, P0526, P140B, P140C, P2228, or P2229 are not set.
A DPF Regeneration is not active.
BARO is between 75-106 kPa (11-15 psi).
Ambient air temperature is between -7 to +38°C (19-100°F).
Engine coolant temperature is between 20 to 108°C (68-226°F).
Engine speed is between 1200 RPM and 1800 RPM for at least 30 s.
Battery voltage is greater than 11 V.
NOx sensor 1 is at operating temperature.
Vehicle speed must be greater than 60 km/h (38 mph).
The DTCs run once per drive cycle when the above conditions are met.

The ECM receives a serial data message from the NOx Sensor Module that the NOx concentration disagrees with the calculated NOx concentration for greater than 5 s.

DTCs P11CB and P11CC are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

In order for the NOx 1 NOx Concentration and NOx 2 NOx Concentration to indicate greater than 0 ppm, the vehicle must be driven until the EGT sensor 3 is greater than 250°C (482°F).

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Ignition ON, observe the DTC information with a scan tool. DTC UXXXX should not be set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) If no DTC is set
Verify the following conditions do not exist : Intake system leaks-Refer to «Charge Air Cooler Diagnosis (Full System Air Leak Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) , «Charge Air Cooler Diagnosis (Induction System Smoke Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) . Exhaust system leaks - Refer to «Exhaust Leakage»(/chevrolet/express-g2500/2013-2013/remont/exhaust/#engine-exhaust-system__exhaust-leakage) . A loose or disconnected charge air cooler hose or pipe. Physical damage. Soot plugged B195 NOx sensor. Loose or missing hardware. Loose B195 NOx sensors or B131 Exhaust Gas Temperature sensors. If a condition is found Repair the intake or exhaust system If no condition is found
Engine running.
Verify NOx 1 NOx Concentration and NOx 2 NOx Concentration are greater than 0 ppm.
Accelerate vehicle to 72 km/h (45 mph) and hold at a steady cruise until the DTC reports PASS or FAIL. If the DTC fails Replace the faulty B195 NOx sensor 1 If the DTC passes
All OK.

«Nitrogen Oxide Sensor Replacement - Position 1»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
Perform the scan tool NOx Sensor 1 Reset procedure after replacing the NOx sensor 1.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
Clear the DTCs.
Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes.
Ignition ON, perform the Reductant System Data Reset with a scan tool order to clear the reductant indicator lamp, if illuminated. If the reductant indicator lamp does not turn OFF A condition with the system still exists If the reductant indicator lamp does turn OFF
All OK.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
NOx Sensor Ignition Voltage	U029D, U029E, P220A, P220B	U029D, U029E	U029D, U029E, P220A, P220B
High Speed GMLAN Serial Data (+)	U0074, P205D	U010E, P205D	U0074, P205D
High Speed GMLAN Serial Data (-)	U029D, U029E, U010E, P205D	U010E, P205D	U010E, P205D
NOx Sensor Ground		U029D, U029E

The ECM varies the amount of diesel exhaust fluid (DEF) or reductant added by varying the reductant injector duty cycle in response to changes in engine exhaust out NOx levels.

DTCs P0101, P0234, P0299, P0401, P0402, P140B, P140C, P2200, P2202, P2203, P2205, U029D and U029E are not set.
Ambient air temperature is greater than -7°C (19°F)
BARO pressure is greater than 75 kPa (11 psi).
EGT sensor 3 is less than 300°C (392° F).
EGT sensor 3 is less than 450°C (842° F) during DPF regeneration
NOx 1 NOx Concentration and NOx 2 NOx Concentration are greater than 0 ppm.
The DTC runs when the above conditions are met.

The ECM receives a serial data message of NOx concentration from NOx Sensor 1 and NOx Sensor 2. During the test phase, the delta NOx concentration at NOx sensor 2 is calculated. If the delta is less than 5 ppm, the diagnostic fails. The test phase begins during a tip-in acceleration event when the conditions for running the DTC are satisfied and completes in approximately 10 s.

DTC P11CE and P229F are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

In order for the NOx 1 NOx Concentration and NOx 2 NOx Concentration to indicate greater than 0 ppm, the vehicle must be driven until the EGT sensor 3 is greater than 250°C (482°F).

Schematic Reference

Connector End View Reference

Component View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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.

Ignition ON, observe the DTC information with a scan tool. DTC UXXXX should not be set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If no DTC is set
Verify the following conditions do not exist: Intake system leaks-Refer to «Charge Air Cooler Diagnosis (Full System Air Leak Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) , «Charge Air Cooler Diagnosis (Induction System Smoke Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) . Exhaust system leaks - Refer to «Exhaust Leakage»(/chevrolet/express-g2500/2013-2013/remont/exhaust/#engine-exhaust-system__exhaust-leakage) . A loose or disconnected charge air cooler hose or pipe. Physical damage. Soot plugged B195 NOx sensor. Loose or missing hardware. Loose B195 NOx sensors or B131 eExhaust Gas Temperature sensors. If a condition is found Repair the intake or exhaust system. If no condition is found
Engine running.
Verify NOx 1 NOx Concentration and NOx 2 NOx Concentration are greater than 1 ppm for 60 s.
Accelerate vehicle to 80 km/h (50 mph) then decelerate with no accelerator pedal input to 72 km/h (45 mph), then continue deceleration with no accelerator pedal input for an additional 2 s.
Perform a hard acceleration to 97 km/h (60 mph.) Continue acceleration and deceleration procedure until the DTC passes or fails on this key cycle. If the DTC fails Replace the B195 NOx sensor - position 2. If the DTC passes
All OK.

«Nitrogen Oxide Sensor Replacement - Position 2»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
Perform the scan tool NOx Sensor 2 Reset procedure after replacing the NOx sensor 2.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
Clear the DTCs.
Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes.
Ignition ON, perform the Reductant System Data Reset with a scan tool in order to clear the reductant indicator lamp, if illuminated. If the reductant indicator lamp does not turn OFF A condition with the system still exists If the reductant indicator lamp does turn OFF
All OK.

The selective catalytic reduction system reduces oxides of nitrogen (NOx) emissions by injecting a metered amount of diesel exhaust fluid (DEF)or reductant into the exhaust gas stream entering the diesel particulate filter (DPF). Within the selective catalytic reduction catalyst, the reductant reacts with the NOx to form nitrogen, carbon dioxide, and water vapor. Upstream and downstream NOx sensors provide the engine control module (ECM) with engine-out and tailpipe-out NOx levels.

The ECM uses the 2 NOx sensors to control exhaust NOx levels. The NOx sensor measures the amount of NOx and oxygen in the exhaust system. The first NOx sensor is located at the outlet of the turbocharger and monitors the engine out NOx. The second NOx sensor is located in the DPF that monitors NOx levels exiting the DPF. The ECM varies the amount of reductant added by varying the reductant injector duty cycle in response to changes in engine exhaust out NOx levels.

BARO pressure is greater than 75 kPa (11 psi).
Ambient air and reductant temperatures are warmer than -7°C (+19°F) and the reductant tank is not in frozen tank status.
Engine speed is between 1,000-3,000 RPM for at least 10 s.
Average selective catalytic reduction temperature is between 240-290°C (464-564°F).
Emission reduction fluid tank level is above 33%.
Battery voltage is greater than 11 V for greater than 3 s.
DPF regeneration is not active.
Engine ON time must be less than 25 minutes.
The DTCs run during key off after-run after the above conditions are met and the fault exists for more than 3 events during a key cycle.

Due to aging and poisoning of the sensor element the characteristics could change and have to be monitored. Therefore a self diagnosis is implemented within the sensor control unit which is determining a measurement deviation in relation to a reference point defined during sensor production.

P11D7

The NOx sensor control unit sends a unique message to the ECM upon the self-diagnosis being aborted. The number of aborts is tracked by the ECM. If the number of self diagnostic aborts exceeds a threshold, the DTC is set.

P22FE

The NOx sensor self diagnostic result is received from the NOx sensor control unit and stored in a ring buffer, which takes the average of the last calibrated number of test results and averages them for comparison to an upper and lower calibrated threshold. If the average result is greater than or less than the calibrated thresholds, a NOx sensor self diagnostic fault will be set.

DTC P11D7 and P22FE are Type A DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Component View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Quality)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Level)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Emission Control)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Anti-Tampering)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy)
«Exhaust Aftertreatment System Description»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation)

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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.

Ignition ON.
Verify DTC UXXX is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If none of the DTCs are set
Replace the B195 NOx sensor - Position 2

«Nitrogen Oxide Sensor Replacement - Position 2»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming and setup.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
NOx Sensor Ignition Voltage	U029D, U029E, P220A, P220B	U029D, U029E	U029D, U029E, P220A, P220B
High Speed GMLAN Serial Data (+)	U0074, P205D	U010E, P205D	U0074, P205D
High Speed GMLAN Serial Data (-)	U029D, U029E, U010E, P205D	U010E, P205D	U010E, P205D
NOx Sensor Ground		U029D, U029E

The ECM varies the amount of diesel exhaust fluid (DEF) or reductant added by varying the reductant injector duty cycle in response to changes in engine exhaust out NOx levels.

P11DB

DTCs P064C, P163C, P2200, P2205, P220A, P220B, U029D and U029E are not set.
Exhaust gas temperature sensor 1 is greater than 95°C (203° F).
Engine speed is greater than 600 RPM.
Battery voltage is greater than 11 V.
A DPF regeneration is not active.
The DTCs run continuously when the above conditions are met.

P11DC

DTCs P064C, P163C, P220A, P220B, P22A3, P229E, U029D and U029E are not set.
Exhaust gas temperature sensor 3 is greater than 95°C (203°F).
Engine speed is greater than 600 RPM.
Battery voltage is greater than 11 V.
A DPF regeneration is not active.
The DTC runs continuously when the above conditions are met.

The ECM receives a serial data message from the NOx Sensor Module that the NOx sensor signal is invalid for greater than 20 s.

DTCs P11DB and P11DC are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

In order for the NOx 1 NOx Concentration and NOx 2 NOx Concentration to indicate greater than 0 ppm, the vehicle must be driven until the Exhaust gas temperature sensor 3 is greater than 250°C (482°F).

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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.

Ignition ON, observe the DTC information with a scan tool. DTC UXXXX should not be set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If no DTC is set
Verify the following conditions do not exist : Intake system leaks-Refer to «Charge Air Cooler Diagnosis (Full System Air Leak Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) , «Charge Air Cooler Diagnosis (Induction System Smoke Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) . Exhaust system leaks - Refer to «Exhaust Leakage»(/chevrolet/express-g2500/2013-2013/remont/exhaust/#engine-exhaust-system__exhaust-leakage) . A loose or disconnected charge air cooler hose or pipe. Physical damage. Soot plugged B195 NOx sensor. Loose or missing hardware. Loose B195 NOx sensors or B131 Exhaust Gas Temperature sensors. If a condition is found Repair the intake or exhaust system. If no condition is found
Engine running.
Verify NOx 1 NOx Concentration and NOx 2 NOx Concentration are greater than 0 ppm.
Accelerate vehicle to 72 km/h (45 mph) and hold at a steady cruise until the DTC reports PASS or FAIL. If the DTC fails Replace the faulty B195 NOx sensor. If the DTC passes
All OK.

«Nitrogen Oxide Sensor Replacement - Position 1»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Nitrogen Oxide Sensor Replacement - Position 2»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
Perform the scan tool NOx Sensor 1 or 2 Reset procedure after replacing the B195 NOx sensor 1 or 2.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
Clear the DTCs.
Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes.
Ignition ON, perform the Reductant System Data Reset with a scan tool order to clear the reductant indicator lamp, if illuminated. If the reductant indicator lamp does not turn OFF A condition with the system still exists If the reductant indicator lamp does turn OFF
All OK.

Fuel Injector Circuits	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Fuel Injector High Voltage Control Cylinder 1	P2146	P0201 1	P1224	P0263
Fuel Injector High Voltage Control Control Cylinder 2	P2152	P0202 1	P1227	P0266
Fuel Injector High Voltage Control Control Cylinder 3	P2155	P0203 1	P122A	P0269
Fuel Injector High Voltage Control Control Cylinder 4	P2146	P0204 1	P1233	P0272
Fuel Injector High Voltage Control Control Cylinder 5	P2152	P0205 1	P1236	P0275
Fuel Injector High Voltage Control Control Cylinder 6	P2149	P0206 1	P1239	P0278
Fuel Injector High Voltage Control Control Cylinder 7	P2149	P0207 1	P1242	P0281
Fuel Injector High Voltage Control Control Cylinder 8	P2155	P0208 1	P1247	P0284
1 Misfire DTCs may also set.

The engine control module (ECM) supplies a high voltage supply circuit and a high voltage control circuit for each fuel injector. The injector high voltage supply circuit and the high voltage control circuit are both controlled by the ECM. The ECM energizes each fuel injector by grounding the control circuit and supplying each fuel injector with up to 250 V and 20 A on the voltage supply circuit to activate the piezo type fuel injectors. This is controlled by boost capacitors in the ECM. During the 250 V boost phase, the capacitor is used to charge the injector piezo stack, allowing for injector opening. The injector is then held open with this high voltage. At the end of the injection event the ECM closes the injector by discharging the injector piezo stack. The ECM monitors the status of the voltage supply and voltage control circuits. The injectors are separated into the following four groups

Group 1- injectors 1 and 4
Group 2- injectors 6 and 7
Group 3- injectors 2 and 5
Group 4- injectors 3 and 8

When a fuel injector circuit fault condition is detected by the ECM, the specific fuel injector, or the two fuel injectors in the affected group may be disabled. DTCs for the injector and/or group may set.

Engine speed is greater than 600 RPM.
The charging system voltage is between 10-18 V.

The ECM injector output driver detects an incorrect current on a fuel injector circuit.
The condition exists for less than 1 s.

DTCs P1224, P1227, P122A, P1233, P1236, P1239, P1242 and P1247 are Type A DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The electronic control module (ECM) is sensitive to resistance on the injector circuits.
Inspect each connector terminal for loose terminal fit or signs of fretting.
Ensure that the ohm meter is zeroed before making any resistance checks.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Engine Running.
Observe the following scan tool parameters. Each parameter should display OK or Not Run. Cylinder 1 Injector Control Circuit Status Cylinder 2 Injector Control Circuit Status Cylinder 3 Injector Control Circuit Status Cylinder 4 Injector Control Circuit Status Cylinder 5 Injector Control Circuit Status Cylinder 6 Injector Control Circuit Status Cylinder 7 Injector Control Circuit Status Cylinder 8 Injector Control Circuit Status If any parameters do not display OK or Not Run Refer to Circuit/System Testing. If all parameters display OK or Not Run
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. If DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

WARNING

Before working on any high voltage fuel injection system, be aware of the following procedures: Do not make contact with the fuel injection harness, engine control module (ECM), or fuel injectors while the ignition is ON or RUN positions. Wait 5 minutes after key OFF to allow the electronic control module (ECM) to discharge before attempting to disconnect or test engine control components. Do not use the electronic control module (ECM) case as a ground while jump starting. Failure to follow the procedure exactly as written may result in serious injury or death.

Observe the DTC information with a scan tool. If DTC P2146, P2149, P2152 or P2155 are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Ignition OFF.
Disconnect the appropriate harness connector at the Q17 Fuel Injector.
Ignition ON.
Test for less than 1 V between the appropriate Fuel Injector High Control Supply circuit terminal 2 and ground. If greater than 1 V Repair the short to voltage in the appropriate Fuel Injector High Voltage Control circuit. If less than 1 V
Replace the K20 Engine Control Module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, programming, and setup

The throttle body is a normally open valve and is only operated during DPF regeneration and when maintaining the selective catalyst reduction temperature. The position of the valve is controlled by the Engine Control Module (ECM). The throttle body system uses a a motor to move the valve to an open or closed position and a position sensor located within the valve assembly is used to monitor the position of the valve.

DTC P02E0 or P02EB is not set.
The ignition is ON.
Offset learning for the throttle valve was successful in the previous driving cycle.
The battery voltage is greater than 8 V.
DTC P122D runs continuously when the above conditions are met.

The ECM detects that the difference between the desired throttle valve position and the actual throttle valve position is greater than 10 % or less than -10 %.

The ECM detects that the learned throttle valve offset position at open or closed position is greater than 20 % or less than -20 %.

The ECM detects that the difference between the maximum and minimum throttle valve position learned at open or closed position is greater than 30 %.

DTC P122D is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Ignition ON, observe the scan tool DTC information. DTC P02E2, P02E3, P02EB, P0697, P122C, P122E, or P122F should not be set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.
Ignition ON, command the Intake Air Flow Valve Motor between 0-100 % with a scan tool. The IAF Valve Desired Position parameter and the IAF Valve Position parameter should match.
Engine idling, observe the scan tool IAF Valve Pos. Sensor voltage parameter. The reading should be between 3.7-4.7 V.
Turn OFF the ignition while observing the scan tool IA Flow Valve Position parameter. The parameter should fluctuate between 0-100 % several times.
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.

Ignition OFF, inspect the Q38 throttle body for the following conditions

A throttle blade that is not in the rest position
A throttle blade that is binding open or closed
A throttle blade that opens or closes without spring pressure
Throttle body for dirt, debris or coking
A damaged throttle valve blade or shaft If a condition is found, clean or replace the Q38 throttle body as necessary.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Throttle Body Assembly Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming and setup.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Fuel Pressure Regulator Solenoid 2 High Control	P125A	P2294	P125B	P128E, P0087, P0088
Fuel Pressure Regulator Solenoid 2 Low Control	P2295	P2294	P2296	P128E, P0087, P0088

The engine control module (ECM) controls the fuel rail pressure by controlling fuel pressure regulator 1 and fuel pressure regulator 2 simultaneously to achieve the desired fuel rail pressure. Fuel pressure regulator 2 is located on the front of the left hand side fuel rail and is used to control the amount of fuel that is bypassed to the fuel return system. Fuel pressure regulator 2 also allows fuel pressure leak down when the engine is OFF.

Engine speed is greater than 600 RPM.
Battery voltage is greater than 11 V.

DTC P125A

The ECM detects low voltage on the supply voltage circuit of Fuel Pressure Regulator 2 for greater than 0.5 s.

DTC P125B

The ECM detects high voltage on the supply voltage circuit of Fuel Pressure Regulator 2 for greater than 0.1 s.

DTC P2294

The ECM detects the commanded state of the driver and the actual state of the control circuit do not match for greater than 1 s.
The ECM detects an open or high voltage on one of the Fuel Pressure Regulator 2 circuits for greater than 1 s.

DTC P2295

The ECM detects the commanded state of the driver and the actual state of the control circuit do not match for greater than 1 s.
The ECM detects low voltage on the control circuit of Fuel Pressure Regulator 2 for greater than 1 s.

DTC P2296

The ECM detects the commanded state of the driver and the actual state of the control circuit do not match for greater than 1 s.
The ECM detects high voltage on the control circuit of Fuel Pressure Regulator 2 for greater than 1 s.

DTCs P125A, P2294, P2295 and P2296 areType A DTCs
DTC P125B is Type B DTC
The ECM commands the engine to operate in the Reduced Engine Power mode.
The message center displays Engine Power Is Reduced.

DTCs P125A, P2294, P2295 and P2296 areType A DTCs
DTC P125B is Type B DTC

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

A failure in the fuel pressure regulator 2 system could cause a crank no start condition.
Intermittent or poor connections may cause this DTC to set.
If the fuel system pressure is actually too high, a fuel knock condition may exist.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

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 DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

Ignition OFF.
Disconnect the harness connector at the Q18B Fuel Pressure Regulator 2.
Connect a test lamp between the high control circuit terminal 1 and ground. Verify the test lamp does not illuminate. If the test lamp illuminates Test the high control circuit for a short to B+. If the circuit tests normal, replace the K20 Engine Control Module . If the test lamp does not illuminate
Ignition ON.
Verify a test lamp illuminates between the high control circuit terminal 1 and ground. If the test lamp does not illuminate Test the high control circuit for an open, high resistance or short to ground. If the circuit tests normal, replace the K20 engine control module. If the test lamp illuminates
Verify that a test lamp does not illuminate between the low control circuit terminal 2 and ground. If the test lamp illuminates Test the low control circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module. If the test lamp does not illuminate
Verify that a test lamp illuminates between the low control circuit terminal 2 and B+. If the test lamp does not illuminate Test the low control circuit for an open or high resistance. If the circuit tests normal, replace the K20 engine control module. If the test lamp illuminates
Ignition OFF.
Observe that the test lamp flashes 2 times and remains OFF until the ECM is powered down. If the test lamp does not flash 2 times and turn off Test the low control circuit for a short to ground. If the circuit tests normal, replace the K20 engine control module. If the test lamp flashes 2 times and turns off
Replace the Q18B Fuel Pressure Regulator 2.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Fuel Pressure Relief Valve Replacement (Fuel Pressure Regulator Valve 2)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) for the Fuel Pressure Regulator 2.
Perform the scan tool «Diesel Particulate Filter (DPF) Regeneration Enable»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__diesel-particulate-filter-dpf-regeneration-enable) , procedure if the scan tool DPF Soot Mass is less than 30 g. If the scan tool DPF Soot Mass is 30 g or greater, perform the «Diesel Particulate Filter (DPF) Service Regeneration»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) procedure.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Fuel Rail Pressure Solenoid Supply Voltage	P125A	P2294	P125B	P0087. P0088. P128E
Fuel Rail Pressure Sensor 5 Volt Reference	P0193, P0641	P0191	P0193, P0641	P0191
Fuel Rail Pressure Sensor Signal	P0192	P0193	P0193	P0191
Fuel Rail Pressure Solenoid Low Reference	P2295	P2294	P2296	P0087. P0088, P128E
Fuel Rail Pressure Low Reference		P0191	1	P0191
1 Opens circuit fuse or opens circuit.

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition ON Parameter Normal Range: 30-219 MPa (4350-31,763 psi)
Fuel Rail Pressure Sensor Signal	0 MPa (0.0 psi)	219 MPa (31,763 psi)	219 MPa (31,763 psi)

Fuel Rail Pressure Sensor

During certain engine operating conditions the engine control module (ECM) checks the actual fuel rail pressure reported from the fuel rail pressure sensor and compares the value to a set programed value. If the values are out of the calibrated range for a set amount of time DTC P128E will set.

Fuel tank level is greater than 15 %
Engine is in crank or run mode

Actual fuel rail pressure is below 15 MPa (2175 psi) for greater than 2 s.
Actual fuel rail pressure exceeds 215 MPa (31,183 psi) for greater than 1 s.

DTC P128E is a Type A DTC.
The ECM commands the engine to operate in the Reduced Engine Power mode.
The message center displays Reduced Engine Power.

DTC P128E is a Type A DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Water in fuel system may cause this DTC to intermittently to set. Refer to «Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures__contaminants-in-fuel-diagnosis)
Gasoline in fuel system may cause this DTC to set.
When power enhancing devices have been attached to the fuel rail pressure sensor circuits, this DTC may set and adversely affect the fuel system components.
The addition of fuel system enhancements, such as auxiliary fuel tanks or add on fuel filters may relate to driveability complaints.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Ignition ON.
Observe the DTC information with a scan tool. Verify no other DTCs are set. If another DTC set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If another DTC did not set
Observe the Fuel Rail Pressure Sensor parameter with a scan tool. During engine cranking, the pressure should be greater than 13 MPa (1885 psi). If 13 MPa (1885 psi) or less Refer to Circuit/System Testing. If greater than 13 MPa (1885 psi)
Observe the Fuel Rail Pressure Sensor parameter with a scan tool, at idle the pressure should be close to the Desired Fuel Rail Pressure. As the engine speed increases, the Desired Fuel Rail Pressure and the Actual Fuel Rail Pressure should closely match each other. If pressure does not closely match Refer to Circuit/System Testing. If pressure closely matches
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 DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

Review the freeze frame data and compare to the conditions to set this DTC. If fuel pressure was low when DTC set Refer to «Fuel System Diagnosis - High Pressure Side»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) . If fuel pressure was not low when DTC set
Engine at idle, command the fuel pressure incrementally through the entire fuel pressure range with a scan tool . The Fuel Rail Pressure Sensor and the Desired Fuel Rail Pressure should be within 690 kPa (100 psi) for the entire fuel pressure range. If the fuel rail pressure sensor and desired fuel rail pressure at idle is within 690 kPa (100 psi) and was not within 690 kPa (100 psi) at 1800 RPM Replace the Q45A Fuel Pressure Regulator 1. If the fuel rail pressure sensor and desired fuel rail pressure at idle was not within 690 kPa (100 psi) but was within 690 kPa (100 psi) at 1800 RPM Replace the Q45B Fuel Pressure Regulator 2. If the fuel rail pressure sensor and desired fuel rail pressure was not within 690 kPa (100 psi) at idle or at 1800 RPM Replace both Q45A Fuel Pressure Regulator 1 and Q45B Fuel Pressure Regulator 2. Inspect the fuel system for contamination, refer to «Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures__contaminants-in-fuel-diagnosis) . If the fuel rail pressure sensor and desired fuel rail pressure at idle is within 690 kPa (100 psi) and was within 690 kPa (100 psi) at 1800 RPM
All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Fuel Pressure Regulator Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) for Q45A Fuel Pressure Regulator 1.
«Fuel Pressure Relief Valve Replacement (Fuel Pressure Regulator Valve 2)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) for Q45B Fuel Pressure Regulator 2.
Perform the scan tool «Diesel Particulate Filter (DPF) Regeneration Enable»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__diesel-particulate-filter-dpf-regeneration-enable) , procedure if the scan tool DPF Soot Mass is less than 30 g. If the scan tool DPF Soot Mass is 30 g or greater, perform the «Diesel Particulate Filter (DPF) Service Regeneration»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) procedure.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup.

The engine control module (ECM) has the ability to learn injector timing performance. With the engine at operating temperature and in closed throttle decel mode, the ECM will pulse each injector individually and measure the changes in rotational speed of the crankshaft using the input from the crankshaft position sensor (CPS). The ECM will run this diagnostic under three different fuel rail pressures for each injector. The ECM will adjust the timing of fuel delivered by each injector to obtain the desired RPM increase. The ECM stores the injector timing value required to increase the crankshaft speed by the desired RPM. If the ECM cannot control an increase in RPM for a given injector the appropriate code will set for that injector.

Ambient air temperature is above -5° C (23° F).
Fuel temperature is between 0-80° C (32-176° F).
Engine temperature is greater the 50° C (122° F).
Battery voltages is greater than 10 V.
Time since last combustion event is between 10-30 s.
Vehicle is in decel fuel shut off mode.
Engine speed is between 950-1850 RPM.
The difference between the Desired Fuel Rail Pressure and the Actual Fuel Rail Pressure is less than 2.2 MPa (320 psi).
No gear change has occurred.
Lambda sensors are adapted.
Vehicle is not in 4WD (if equipped).
Exhaust brake is not ON (if equipped).
No other DTCs are present.
The DTC runs when the above conditions exists.

Zero fuel correction has reached maximum value for greater than 10 s.

DTCs P12B3, P12B5, P12B7, P12B9, P12BB, P12BD, P12BF and P12C1 are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This Diagnostic parameter is stored in the ECM over a period of time. Time to set this DTC may take several drive cycles.
Contaminated or improper fuel quality may cause this DTC to set.
Worn base engine components or differences in cylinder compression may cause this DTC to set

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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.

Verify the proper fuel is used. Refer to «Fuel System Specifications»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications) , and «Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures__contaminants-in-fuel-diagnosis) .
Verify there are no aftermarket performance enhancing devices install on the vehicle.

Perform a cylinder compression test. Refer to Engine Compression Test .

If the engine compression is within specifications replace the appropriate Q17 fuel injector.

Perform the Diagnostic Repair Verification after completing the diagnostic repair.

«Fuel Injector Replacement (Right Side)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__fuel-injector-replacement-right-side) , «Fuel Injector Replacement (Left Side)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__fuel-injector-replacement-left-side)
Perform the «Fuel Injector Flow Rate Programming»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) , and «Fuel Injector Correction Reset»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) procedures after replacement of a fuel injector.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup.

Ambient air temperature is above -5° C (23° F)
Fuel temperature is between 0-80° C (32-176° F)
Engine temperature is greater the 50° C (122° F)
Battery voltages is greater than 10 V.
Time since last combustion event is between 10-30 s.
Vehicle is in decel fuel shut off mode
Engine speed is between 950-1850 RPM
The difference between the Desired Fuel Rail Pressure and the Actual Fuel Rail Pressure is less than 2.2 MPa (320 psi)
No gear change has occurred
Lambda sensors are adapted
Vehicle is not in 4WD (if equipped)
Exhaust brake is not ON (if equipped)
No other DTCs are present
The DTC runs when the above conditions exists

Zero fuel correction has reached maximum value for greater than 10 s.

DTCs P12B4, P12B6, P12B8, P12BA, P12BC, P12BE, P12C0 and P12C2 are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This Diagnostic parameter is stored in the ECM over a period of time. Time to set this code may take several drive cycles.
Contaminated or improper fuel quality may cause this code to set
Worn base engine components or differences in cylinder compression may cause this code to set

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Verify the proper fuel is used. Refer to «Fuel System Specifications»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications) , and «Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures__contaminants-in-fuel-diagnosis) .
Verify there are no aftermarket performance enhancing devices install on the vehicle.

Perform a cylinder compression test. Refer to Engine Compression Test .

If the engine compression is within specifications replace the appropriate Q17 fuel injector.

Perform the Diagnostic Repair Verification after completing the diagnostic repair.

«Fuel Injector Replacement (Right Side)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__fuel-injector-replacement-right-side) , «Fuel Injector Replacement (Left Side)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__fuel-injector-replacement-left-side)
Perform the «Fuel Injector Flow Rate Programming»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) , and «Fuel Injector Correction Reset»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) procedures after replacement of a fuel injector.
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming and setup.

The exhaust gas recirculation (EGR) valve is controlled by the engine control module (ECM). The ECM controls the EGR valve by supplying a 12-volt pulse width modulated (PWM) signal to the EGR solenoid low control circuit and 12 volts to the high control circuit. The ECM monitors the difference between the desired Mass Air Flow (MAF) and the actual MAF over a calibrated sampling time. If the average difference between desired and actual MAF during the specified time period is less than or greater than a calibrated threshold level the response time of detected EGR flow is determined to be out of range.

DTC P0045, P0047, P0048, P006E, P006F, P007C, P007D, P008F, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0128, P0200, P02E0, P02E7, P02E8, P02E9, P02EB, P0400, P0403, P0405, P0406, P0489, P0490, P122C, P122E, P122F, P140D, P140E, P140F, P1407, P1411, P1412, P1413, P1414, P168C, P168D, P16A0, P16A1, P16A2, P2228, P2229, P2263, P2453, P245A, P245C, P245D, P2493, P2494, P2495, P2564, P2565, P2598, or P2599, is not set.
The engine speed is between 1,300-2,000 RPM.
The calculated fuel rate is between 28-55 mm 3
The ambient air temperature is greater than -7°C (19.4°F).
The engine coolant temperature is greater than 70°C (158°F)
The Barometric Pressure is greater than 74.8 kPa (10.9 psi).
The MAF rate is not in a steady state condition.
The EGR valve is in closed loop and active.
The DTCs run continuously when the above conditions are met.

The ECM detects that the average integrated difference between the actual mass air flow and the desired mass air flow is not within a minimum or maximum calibrated range over a 15 s time period.

DTC P140B and P140C are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Inspect for the following conditions that may cause this DTC to set

Contamination on the MAF sensor element
Restriction before or after the MAF sensor
Skewed MAF sensor
Aftermarket air filter

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool Desired EGR Position and the EGR Position Sensor parameters. Command the EGR valve between 0-40 % and back down to 0 % within 20 s with a scan tool. The parameters should respond quickly and remain within 3 % throughout the commanded range.
Engine running command the EGR Valve to 40 % with a scan tool, then increase the engine speed to 2,500 RPM. The engine should run rough.
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.

Note. Perform the Circuit System Verification before proceeding with Circuit/System Testing. Always replace the EGR valve or EGR cooler gaskets when removal or replacement of the components are necessary. Recording of Mass Air Flow parameter g/s are valid only if the Reduced Engine Power message is not present.

Engine running, perform the following: Maintain engine speed at idle. With a scan tool, command the EGR solenoid to 0 % and record the MAF Sensor g/s parameter. Command the EGR solenoid to 40 % with a scan tool while observing the EGR Position Sensor and the MAF Sensor g/s parameters. Record the MAF Sensor parameter. The difference between the MAF Sensor parameter at 0 % EGR solenoid position and 40 % EGR solenoid position should be greater than 15 g/s. If the MAF Sensor parameter is not within the specified range, inspect the EGR cooler and the EGR valve passages for a restriction. If a condition is found, repair or replace the affected component as necessary.
Ignition OFF, inspect for the following: The exhaust system for leaks, restrictions, or for modification of the Original Equipment Manufacturer (OEM) part A restriction in the air cleaner and the air intake ducts A restriction in the turbocharger charge air cooler system A restriction in the intake manifold If a condition is found, repair or replace the affected component as necessary.
Test the air induction system for air leaks between the MAF sensor and the turbocharger. Perform the Induction System Smoke Test. Refer to «Charge Air Cooler Diagnosis (Full System Air Leak Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) , «Charge Air Cooler Diagnosis (Induction System Smoke Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) .
Test the charge air cooler system for leaks. Perform the Full System Air Leak Test. Refer to «Charge Air Cooler Diagnosis (Full System Air Leak Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) , «Charge Air Cooler Diagnosis (Induction System Smoke Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) .
If the exhaust, air induction, charge air cooler and mass air flow systems test normal, Test or replace the Q14 EGR Valve.

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

Ignition OFF, remove the Q14 EGR valve. Refer to «Exhaust Gas Recirculation Valve Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) .
Inspect the Q14 EGR valve for the following conditions: A sticking, binding, or frozen EGR valve A leak or restriction in the EGR valve and EGR ports and passages Any coking, soot build up, debris or damage that can cause the EGR valve to stick partially open or closed If a condition is found, replace the Q14 EGR Valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Exhaust Gas Recirculation Valve Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup

The particulates in the exhaust gases are collected by the diesel particulate filter (DPF). When the filter becomes saturated with particulates, they are oxidized by a regeneration process. The regeneration process increases the exhaust gas temperature, heating the diesel oxidation catalyst (DOC), and the DPF. The accumulated particulate matter in the DPF will then be safely converted to harmless gases and the DPF will then be clean and ready to filter additional particulate matter.

The engine control module (ECM) monitors the system with inputs from the exhaust gas temperature (EGT) sensors and a differential pressure sensor. This diesel particulate filter diagnostic provides a means for monitoring the exhaust particulate filter efficiency. The resistive exhaust flow is monitored to determine if a DPF substrate is missing or a defined DPF failure has occurred. The resistive exhaust flow is calculated from mass air flow and DPF differential pressure. This diagnostic will run after a successful regeneration event has completed. This includes a successful service regeneration event.

P144B or P144C

DTCs P0101, P0102, P0103, P0420, P10CD, P202E, P20CB, P20CD, P2263, P2463, P2598, or P2599 are not set..
Engine speed is greater than 900 RPM for at least 10 s.
Ignition voltage is greater than 11 V.
ECM is commanding a DPF regeneration.
Vehicle speed is a steady 89 km/h(55 mph).
Exhaust temperature sensor 1 is between 100-650°C (212-1,200°F).
Exhaust temperature sensor 1 and 4 is less than 650°C (1,200°F).
The DTCs run continuously once the above conditions are met for 15 minutes.

P24A0 or P24A1

DTCs P0101, P0102, P0103, P0420, P10CD, P202E, P20CB, P20CD, P2263,P2463, P2598, or P2599 are not set.
Engine speed is greater than 900 RPM for at least 10 s.
ECM is commanding a DPF regeneration.
Vehicle speed is greater than 24 km/h (15 mph).
Exhaust temperature sensor 1 and 4 is greater than 230°C (446°F).
Exhaust temperature sensor 1 and 4 is less than 750°C (1,382°F).
The DTCs run continuously once the above conditions are met for 10 minutes.

The exhaust gas temperature is less than or greater than the calibrated desired temperature.

DTCs P144B, P144C, P24A0, and P24A1 are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Component View Reference

Description and Operation Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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.

Ignition On.
Verify no other DTCs are set. If any DTCs set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) If no DTCs set
Measure and record the resistance of the B131 Exhaust Gas Temperature sensor 1 and 2. Compare the measurements to the «Temperature Versus Resistance (Fuel Temperature Sensor)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-fuel-temperature-sensor) , «Temperature Versus Resistance (ECT Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-ect-sensors) , «Temperature Versus Resistance (IAT Sensor 1)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-iat-sensor-1) , «Temperature Versus Resistance (IAT Sensor 2)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-iat-sensor-2) , «Temperature Versus Resistance (EGT Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-egt-sensors) , «Temperature Versus Resistance (EGR Temperature Sensors)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-egr-temperature-sensors) , «Temperature Versus Resistance (Emission Reduction Fluid Injector)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-specifications__temperature-versus-resistance-emission-reduction-fluid) table. The resistance values should be within the specified range indicated in the table. If not within the specified range Replace the appropriate B131 Exhaust Gas Temperature sensor. If within the specified range
Inspect for the following conditions: Intake system for leaks or restrictions. Perform the Induction System Smoke Test in «Charge Air Cooler Diagnosis (Full System Air Leak Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) , «Charge Air Cooler Diagnosis (Induction System Smoke Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) . Exhaust system for leaks or restrictions-Refer to «Symptoms - Engine Exhaust»(/chevrolet/express-g2500/2013-2013/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) . Fuel system for leaks or restrictions. Q57 Indirect Fuel Injector leaking or restricted-Refer to «Exhaust Aftertreatment Fuel Injector Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) . Excessive water in fuel-Refer to «Contaminants-in-Fuel Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures__contaminants-in-fuel-diagnosis) . EGR for normal operation. Plugged fuel filter. Restricted air filter. Turbocharger for normal operation. An engine mechanical condition. If a condition is found Repair as necessary If no condition is found
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.
Verify the DTC does not set. If the DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) If the DTC does not set
All OK.

«Exhaust Temperature Sensor Replacement - Position 1»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Exhaust Temperature Sensor Replacement - Position 2»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
Clear the DTCs.
Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes.
Perform the scan tool «Diesel Particulate Filter (DPF) Regeneration Enable»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__diesel-particulate-filter-dpf-regeneration-enable) .
Engine idling at operating temperature. Accelerate at part throttle to 48 km/h (30 mph) with this speed maintained until all Conditions for Running the DTC are met. The test is complete once the DTCs have run and passed.

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.

DTCs P0506, P0507, or U0101 are not set.
The engine is running 0.5 s.
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.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Description and Operation

Data Link Communications Description and Operation

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

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.

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-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If only DTC P150C is set
Replace the K17 Electronic Brake Control Module.
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.
Verify the DTC does not set. If the DTC sets Replace the K20 Engine Control Module. If the DTC does not set
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.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Intake Air Heater Digital Response Signal	P154A	P154A	P154A

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Component Commanded ON Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component ON - OK for Open/Short to GND and Short to B+ test. Component OFF - OK for Open/Short to GND and Short to B+ test.
Intake Air Heater Digital Response Signal	Malfunction	Malfunction

Intake Air Heater Feedback Circuit Status Short to Gnd, Short to Volt Test Status - Component Commanded ON

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Component Commanded OFF Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component ON - OK for Open/Short to GND and Short to B+ test. Component OFF - OK for Open/Short to GND and Short to B+ test.
Intake Air Heater Digital Response Signal	Malfunction	Malfunction	Malfunction

Intake Air Heater Feedback Circuit Status Short to Gnd, Short to Volt Test Status - Component Commanded OFF

The intake air heater is located in the air inlet tube and is used to warm the incoming air to aid in cylinder combustion during cold weather operation. The engine control module (ECM) sends commands to the glow plug control module to enable or disable the intake air heater when certain conditions met. The glow plug control module monitors the voltage and feedback circuits of the intake air heater to verify proper operation. If the Intake Air Heater Digital Response Signal circuit does not match the commanded state of the intake air heater or is opened, shorted to voltage or short to ground DTC P154A may set.

Engine speed is greater than 600 RPM.
The intake air heater is commanded ON.
The battery voltage is more than 8.6 V.
DTCs P154A runs continuously when the above conditions exists.

The glow plug control module detects an open, short to ground or short to battery voltage on the intake air heater digital response signal circuit for less than 1 s.

DTC P154A is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

This DTC may only occur when the intake air heater is hot.
The scan tool does not allow the IAH to operate at 100% and may not produce the fault condition. If the DTC is intermittent the most likely cause is the IAH.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Engine running.
Command the Intake Air Heater ON and OFF, with a scan tool while observing the Intake Air Heater Feedback Circuit Status parameter. The Intake Air Heater Feedback Circuit Status parameter should display OK. If parameter does not display OK Refer to Circuit/System Testing. If parameter displays OK
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 DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

Test the Intake Air Heater Digital Response Signal circuit between the K34 Glow Plug Control Module connector X2 terminal 17 and the E24 Intake Air Heater connector X1 terminal 6 of the E24 Intake Air Heater for an open, a short to ground, or a short to voltage. If a condition is found Repair as necessary. If no condition is found
Ignition OFF.
Disconnect the E24 Intake Air Heater X1 harness connector. Connect any other circuits that were previously disconnected.
Ignition ON.
Command the E24 Intake Air Heater OFF with a scan tool , measure the frequency between Intake Air Heater Heart Beat Signal circuit terminal 3 and ground, Verify the frequency is within 0.78-1.1 Hz. If not within 0.78-1.1 Hz Replace the K34 Glow Plug Control Module. If within 0.78-1.1 Hz
Ignition OFF.
Install a jumper wire between Intake Air Heater Temperature Signal circuit terminal 1 and the corresponding terminal on the E24 Intake Air Heater.
Install a jumper wire between the Intake Air Heater Heart Beat Signal circuit terminal 3 and the corresponding terminal on the E24 Intake Air Heater.
Supply 12 volts to the Intake Air Heater Switch On/Off Signal circuit terminal 2 on the E24 Intake Air Heater.
Ignition ON.
Measure the frequency between the Intake Air Heater Digital Response Signal circuit terminal 6 at the intake air heater and ground. Verify the frequency is within 0.7-1.1 Hz If not within 0.7-1.1 Hz Replace the E24 Intake Air Heater. If within 0.7-1.1 Hz
Replace the E24 Intake Air Heater and clear the DTC. Road test the vehicle under the conditions to run the DTC. If the DTC sets, replace the K34 Glow Plug Control Module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Intake Air Heater Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for glow plug control module replacement, programming, and setup.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Intake Air Heater Voltage Feedback Signal	P154B	P154B	P154B
Intake Air Heater Switch On/Off Signal	P154B	P154B	P0640
Intake Air Heater Heart Beat Signal	P154B	P154B	P154B

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Component Commanded ON Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component ON - OK for Open/Short to GND and Short to B+ test. Component OFF - OK for Open/Short to GND and Short to B+ test.
Intake Air Heater Voltage Feedback Signal	Malfunction	Malfunction	Malfunction

Intake Air Heater Voltage Signal Circuit Status - Component Commanded ON

The intake air heater is located in the air inlet tube and is used to warm the incoming air to aid in cylinder combustion during cold weather operation. The engine control module (ECM) sends commands to the glow plug control module to enable or disable the IAH when certain conditions met. The glow plug control module monitors the voltage and feedback circuits of the intake air heater to verify proper operation. If any of the following circuits are open, shorted to voltage, or shorted to ground DTC P154B may set.

Intake Air Heater Voltage Feedback Signal
Intake Air Heater Switch On/Off Signal
Intake Air Heater Heart Beat Signal

The intake air heater is commanded ON.
The glow plug control module battery voltage is between 9.5-15 V.
DTC P154B runs continuously when the above condition is met.

DTC will set when any of the following conditions exists

Intake air heater voltage is greater than 16 V while the glow plug control module voltage is between 9.5-14 V for more than 650 ms.
Intake air heater voltage is less than 6.9 V while the glow plug control module voltage is between 9.5-16 V for more than 1000 ms.
Intake air heater signal voltage is greater than 1.5 V after the intake air heater has been commanded OFF for more than 65 ms.

DTC P154B is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

A poor intake air heater ground or loose connection on the battery positive voltage circuit may cause this DTC to set.
This DTC may only occur when the intake air heater is hot.
The scan tool does not allow the IAH to operate at 100% and may not produce the fault condition. If the DTC is intermittent the most likely cause is the IAH.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Engine running.
All accessories OFF, measure and record the battery voltage at the battery terminals. The voltage should be between 12.6 and 15.0 V. If not between 12.6 and 15.0 V Refer to «Charging System Test»(/chevrolet/express-g2500/2013-2013/remont/charging-system/#battery-charging-system-and-starting-system) . If between 12.6 and 15.0 V
Ignition ON.
Verify the scan tool Intake Air Heater Voltage Status parameter displays OK. If parameter does not display OK Refer to Circuit/System Testing. If parameter displays OK
Verify the scan tool Intake Air Heater and Ignition 1 Signal voltage parameters closely match. If parameters do not closely match Refer to Circuit/System Testing. If parameters closely match
Verify the E24 Intake Air Heater can be commanded ON and OFF with a scan tool. If the E24 Intake Air Heater cannot be commanded ON and OFF Refer to Circuit/System Testing. If the E24 Intake Air Heater can be commanded ON and OFF
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 DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

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

Measure and record the voltage between the Battery Positive Voltage circuit terminal 1 X2 at the intake air heater and ground. If voltage is not B+ Repair the open or high resistance in the Battery Positive Voltage circuit. If voltage is B+
Test the following circuits for an open, short to ground, or short to voltage: The Intake Air Heater Voltage Feedback Signal circuit between terminal 23 X2 of the glow plug control module and terminal 5 X1 of the intake air heater. The Intake Air Heater Switch On/Off Signal circuit between terminal 30 X2 of the glow plug control module and terminal 2 X1 of the intake air heater. The Intake Air Heater Heart Beat Signal circuit between terminal 31 X2 of the glow plug control module and terminal 3 X1 of the intake air heater. If an open, short to ground, or short to voltage was found Repair as necessary. If no open, short to ground, or short to voltage was found
Connect any circuits that were disconnected.
Ignition ON.
Verify the scan tool displays the Intake Air Heater Voltage Status parameter as OK. If parameter does not display OK Replace the E24 Intake Air Heater. If parameter displays OK
Replace the E24 Intake Air Heater and clear the DTC. Road test the vehicle under the conditions to run the DTC. If the DTC sets, replace the K34 Glow Plug Control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Intake Air Heater Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for glow plug control module replacement, programming, and setup

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Intake Air Heater Current Feedback Signal	P154C	P154C	P154C

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Component Commanded ON Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component ON - OK for Open/Short to GND and Short to B+ test. Component OFF - OK for Open/Short to GND and Short to B+ test.
Intake Air Heater Current Feedback Signal	Malfunction	Malfunction	Malfunction

Intake Air Heater Current Signal Circuit Status - Component Commanded ON

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Component Commanded OFF Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component ON - OK for Open/Short to GND and Short to B+ test. Component OFF - OK for Open/Short to GND and Short to B+ test.
Intake Air Heater Current Feedback Signal	Malfunction	Malfunction	Malfunction

Intake Air Heater Current Signal Circuit Status - Component Commanded OFF

The intake air heater is located in the air inlet tube and is used to warm the incoming air to aid in cylinder combustion during cold weather operation. The engine control module (ECM) sends commands to the glow plug control module to enable or disable the intake air heater when certain conditions met. The glow plug control module monitors the voltage and feedback circuits of the intake air heater to verify proper operation. If the Intake Air Heater Current Feedback Signal circuit is opened, shorted to voltage, or shorted to ground DTC P154C may set.

The intake air heater is commanded ON.
The intake air heater battery voltage is more than 6.9 V.
Glow plug control module ignition voltage is more than 6.9 V.
DTC P154C runs continuously when the above conditions are met.

DTC will set when any of the following conditions exists.

Intake air heater current is less the 20 A when the duty cycle is high for more than 320 ms.
Intake air heater current is out of range when the duty cycle is commanded low for more than 5000 ms.
The Intake Air Heater Current Feedback Signal voltage is greater than 4.96 V for more than 650 ms.
The glow plug control module determines the intake air heater resistance is greater than 500 ohms when current flow is greater than 20 A for more than 160 ms.

DTC P154C is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

This DTC may only occur when the intake air heater is hot.
The scan tool does not allow the IAH to operate at 100% and may not produce the fault condition. If the DTC is intermittent the most likely cause is the IAH.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Engine running.
Command the intake air heater ON and OFF with a scan tool while observing the Intake Air Heater Current Signal Circuit Status parameter. The Intake Air Heater Current Signal Circuit Status parameter should display OK. If parameter does not display OK Refer to Circuit/System Testing. If parameter displays OK
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 DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

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

Test the Intake Air Heater Current Feedback Signal circuit between the intake air heater connector X1 terminal 4 and glow plug control module connector X2 terminal 16 for an open, short to ground, or short to voltage. If a condition is found Repair as necessary. If a condition is not found
Ignition OFF.
Disconnect the intake air heater X1 harness connector. Connect any other circuits that were previously disconnected.
Ignition ON.
Command the intake air heater OFF with a scan tool, measure the frequency between the Intake Air Heater Heart Beat Signal circuit terminal 3 and ground. Verify the frequency is within 0.78-1.1 Hz. If not within 0.78-1.1 Hz Replace the K34 Glow Plug Control Module. If within 0.78-1.1 Hz
Ignition OFF.
Install a jumper wire between temperature signal circuit terminal 1 and the corresponding terminal on the intake air heater.
Install a jumper wire between the Intake Air Heater Heart Beat Signal circuit terminal 3 and the corresponding terminal on the intake air heater.
Supply B+ to the Intake Air Heater Switch On/Off Signal circuit terminal 2 on the intake air heater.
Ignition ON.
Measure the frequency between the Intake Air Heater Current Feedback Signal circuit terminal 4 at the intake air heater and ground. Verify the frequency is within 0.7-1.1 Hz. If not within 0.7-1.1 Hz Replace the E24 Intake Air Heater. If within 0.7-1.1 Hz
Replace E24 Intake Air Heater and clear the DTC. Road test the vehicle under the conditions to run the DTC. If the DTC sets, replace the K34 Glow Plug Control Module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Intake Air Heater Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for glow plug control module replacement, programming, and setup.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Intake Air Heater Temperature Signal	P154D	P154D	P154D

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition ON Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component ON - OK for Open/Short to GND and Short to B+ test. Component OFF - OK for Open/Short to GND and Short to B+ test.
Intake Air Heater Temperature Signal	Malfunction	Malfunction	Malfunction

Intake Air Heater Temperature Signal Circuit Status

The intake air heater is located in the air inlet tube and is used to warm the incoming air to aid in cylinder combustion during cold weather operation. The engine control module (ECM) sends commands to the glow plug control module to enable or disable the intake air heater when certain conditions met. The glow plug control module monitors the voltage and feedback circuits of the intake air heater to verify proper operation. If the Intake Air Heater Temperature Signal circuit is opened, shorted to voltage, or shorted to ground DTC P154D may set.

The intake air heater is commanded ON.
The intake air heater battery voltage is between 6.9-16 V.
DTC P154D runs continuously when the above conditions are met.

The glow plug control module detected an open, short to ground or short to battery on the intake air heater temperature signal circuit for greater than 650 ms.
The intake air heater temperature sensor value is less than -20°C (-4°F) and the intake air temperature sensor is greater than 20°C (68°F).

DTC P154D is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

A poor intake air heater ground may cause this DTC to set.
This DTC may only occur when the intake air heater is hot.
The scan tool does not allow the IAH to operate at 100% and may not produce the fault condition. If the DTC is intermittent the most likely cause is the IAH.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Observe the following with a scan tool.

Engine running.
Observe the Intake Air Heater Temperature Signal Circuit Status parameter with a scan tool. The Intake Air Heater Temperature Signal Circuit Status parameter should display OK. If parameter does not display OK Refer to Circuit/System Testing. If parameter displays OK
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 DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

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

Ignition OFF.
Disconnect the X1 harness connector of the E24 Intake Air Heater.
Ignition ON.
Measure for 4-5 V between the temperature signal circuit terminal 1 of the intake air heater X1 connector and ground. If greater than 5 V Test the temperature signal circuit for a short to voltage. If the circuit tests normal, replace the K34 Glow Plug Control Module. If less than 4 V Test the temperature signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace E24 Intake Air Heater and clear the DTC. Road test the vehicle under the conditions to run the DTC. If the DTC sets, replace the K34 Glow Plug Control Module. If within 4-5 V
Replace the E24 Intake Air Heater.

Disconnect the E24 Intake Air Heater and measure between the temperature signal circuit terminal 1 on the intake air heater and ground for 15,000-18,000 ohms with a DMM. If not within 15,000-18,000 ohms Replace the E24 Intake Air Heater If within 15,000-18,000 ohms
All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Intake Air Heater Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for glow plug control module replacement, programming, and setup.

The body control module (BCM) is constantly sending serial data messages to the engine control module (ECM) regarding the operating state of the power take off system. These messages are sent in a continuously repeating series of rolling counts with associated password protect samples and each count/sample is assigned a value. When the ECM determines that too many of the counts/samples contain an error value, the ECM sets DTC P1591.

This DTC runs continuously when the ignition is on.

The ECM detects that 4 of 10 counts/samples contain an error value.

DTC P1591 is a Type C DTC.

DTC P1591 is a Type C DTC

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for a overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

An intermittent fault in the CAN circuits will cause the ECM to set DTC P1591.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Note. DTC P1591 is an informational DTC. Diagnose all other engine control module DTCs prior to DTC P1591.

Verify there are no other engine control module or communication DTCs set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) If a DTC is not set
Complete the diagnosis by looking for an intermittent CAN circuit fault. Refer to «Scan Tool Does Not Communicate with High Speed GMLAN Device»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#data-communication-system) . If an intermittent CAN circuit fault is found Refer to Circuit/System Testing. If an intermittent CAN circuit fault is not found
All OK.

Verify that no other DTCs are set except for DTC P1591. If any other DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If only DTC P1591 is set
Replace the K9 Body Control Module.
Verify the DTC does not set while operating the vehicle within the Conditions for Running the DTC. If DTC sets Replace the K20 Engine Control Module. If DTC does not set
All OK.

Perform the Diagnostic Repair Verification after completing the repair.

«Body Control Module Replacement»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#data-communication-system)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Engine Control Module replacement, programming, and setup.

The control functions for the fuel injection system are integrated in the engine control module (ECM). During the manufacturing process, each injector's flow rate is measured and recorded as injection quantity adjustment (IQA) flow rate data. The flow rate data is then etched as a hexadecimal number on the body of the injector. This data, together with the injector's cylinder position, is stored in the memory of both the glow plug control module (GPCM) and the ECM. When the ignition is turned ON, the GPCM and the ECM compare the IQA Data . If any of the injector flow rate numbers are incorrect in either of the control modules, this diagnostic will set the appropriate DTC.

The ignition is ON.

The fuel injector calibration flow rate data is incorrect, or not programmed.

DTCs P160C, P268A, P268C, P268D, P268E, P268F, P2690, P2691, P2692 and P2693 are Type A DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Review the Injector Flow Identifier function with a scan tool. All cylinders should be programmed with a flow rate number. Both the GPCM and the ECM should be programmed with the same flow rate numbers for the corresponding cylinders. If flow rate numbers are incorrect, refer to «Fuel Injector Flow Rate Programming»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) .
Engine running, observe the DTC information with a scan tool. DTCs P160C, P268A, P268C, P268D, P268E, P268F, P2690, P2691 or P2693 should not set.
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.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

This diagnostic addresses if the glow plug control module (GPCM) is not programmed.

DTC P161A runs continuously when the ignition is ON.

The glow plug control module (GPCM) is not programmed.

DTC P161A is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Observe the DTC information with a scan tool. DTC P161A should not set.

If DTC P161A set this ignition, program the K34 Glow Plug Control Module. Refer to «Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) . If DTC P161A resets replace the K34 Glow Plug Control Module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for glow plug control module replacement, programming, and setup.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Battery Positive Voltage		P163C		P163C
Run/Crank Ignition 1 Voltage		P163C		P163C

The Glow Plug Control Module (GPCM) has the ability to perform internal diagnostics for voltage and output state of the glow plugs. The GPCM monitors the battery voltage of the module's main voltage supply circuit, the Ignition 1 Signal circuit and the Engine Control Module (ECM) Voltage circuit. If the GPCM detects a difference between the GPCM main battery supply circuit and the Ignition 1 Signal circuit greater than 5 V the DTC will set or if the GPCM detects a difference of 3 V between the GPCM main battery supply circuit and the ECM Voltage circuit. The GPCM will send a message to the ECM to set this DTC.

The ignition is ON.
DTC P163C runs continuously.

The GPCM detects a variation between the battery positive voltage circuit to the GPCM, Ignition 1 signal circuit, and/or the ECM voltage circuit for 130 ms. The following conditions will set the DTC

GPCM battery positive voltage circuit is greater than 16.5 V, and ignition 1 signal circuit is between 9-14 V.
GPCM battery positive voltage circuit is less than 6 V, and ignition 1 signal circuit is between 9-16 V.
The difference between the GPCM battery positive voltage circuit, and ignition 1 signal circuit is greater than 5 V during glow plug operation.
The difference between the GPCM battery positive voltage circuit and the ECM voltage circuit is greater than 3 V during glow plug operation.

DTC P163C is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Intermittent or poor connection of the B+ cable at the GPCM connector X1 may cause this DTC to set.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Engine running.
All accessories OFF, measure and record the battery voltage at the battery terminals. The voltage should be between 12.6 and 15 V. If not between 12.6 and 15 V Refer to «Charging System Test»(/chevrolet/express-g2500/2013-2013/remont/charging-system/#battery-charging-system-and-starting-system) . If between 12.6 and 15 V
Verify the scan tool ECM Voltage Signal parameter reading is between 12.6 and 15 V. If not between 12.6 and 15 V Refer to Circuit/System Testing. If between 12.6 and 15 V
Verify the scan tool GPCM Ignition 1 Signal parameter is between 12.6 and 15 V. If not between 12.6 and 15 V Refer to Circuit/System Testing. If between 12.6 and 15 V
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 DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

Ignition OFF.
Disconnect the X1 harness connector at the K34 Glow Plug Control Module.
Measure and record the voltage between the battery positive voltage circuit terminal 1 of the X1 harness connector and ground. The voltage should be B+. If voltage is not B+ Repair the open or high resistance in the battery positive voltage circuit. If voltage is B+
Disconnect the X2 harness connector at the K34 Glow Plug Control Module.
Ignition ON.
Measure and record the voltage between the Run/Crank Ignition 1 Voltage circuit terminal 33 and ground. The voltage should be B+. If voltage is not B+ Repair the open or high resistance in the Run/Crank ignition 1 voltage circuit. If voltage is B+
Measure and record the voltage between B+ and the signal ground circuit terminal 10. The voltage should be B+. If voltage is not B+ Repair the open or high resistance in the signal ground circuit. If voltage is B+
Replace the K34 Glow Plug Control Module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for GPCM replacement, programming, and setup.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Run/Crank Ignition 1 Voltage		P163D
Glow Plug Supply Voltage (1)	P0671	P163D, P0671	P163D, P0671
Glow Plug Supply Voltage (2)	P0672	P163D, P0672	P163D, P0672
Glow Plug Supply Voltage (3)	P0673	P163D, P0673	P163D, P0673
Glow Plug Supply Voltage (4)	P0674	P163D, P0674	P163D, P0674
Glow Plug Supply Voltage (5)	P0675	P163D, P0675	P163D, P0675
Glow Plug Supply Voltage (6)	P0676	P163D, P0676	P163D, P0676
Glow Plug Supply Voltage (7)	P0677	P163D, P0677	P163D, P0677
Glow Plug Supply Voltage (8)	P0678	P163D, P0678	P163D, P0678
Signal Ground		P163D	P163D

Circuit	Short to Ground	Open
Operating Conditions: Ignition ON, Glow Plugs OFF Parameter Normal Range: less than 0.70 ohms
Cylinder 1 Glow Plug Resistance	0 ohms	65.5 ohms
Cylinder 2 Glow Plug Resistance	0 ohms	65.5 ohms
Cylinder 3 Glow Plug Resistance	0 ohms	65.5 ohms
Cylinder 4 Glow Plug Resistance	0 ohms	65.5 ohms
Cylinder 5 Glow Plug Resistance	0 ohms	65.5 ohms
Cylinder 6 Glow Plug Resistance	0 ohms	65.5 ohms
Cylinder 7 Glow Plug Resistance	0 ohms	65.5 ohms
Cylinder 8 Glow Plug Resistance	0 ohms	65.5 ohms

Glow Plug 1-8

The Glow Plug Control Module (GPCM) has the ability to perform internal diagnostics for voltage and output state of the glow plugs. If the GPCM receives a command to turn on the glow plugs and Ignition 1 Signal voltage is low this code will set. If the GPCM detects voltage on the glow plug circuits while glow plugs are not commanded on this code will set. If the GPCM detects a ground offset of 1.5 volts between the GPCM ground and the glow plug ground circuit this code will set. The GPCM will send a message to the Engine Control Module (ECM) to set this DTC.

The ignition is ON.
DTC P163D runs continuously.

DTC will set when any of the following conditions exists

GPCM detects 0 volts on the Ignition 1 Signal circuit while glow plugs are commanded ON for greater than 1000 ms.
GPCM detects voltage on the glow plug supply voltage circuit when glow plugs are commanded OFF for greater than 60 ms.
GPCM detects a ground offset greater than 1.5 volts between the GPCM Signal Ground circuit and glow plug ground circuits while the glow plugs are commanded ON for greater than 200 ms.

DTC P163D is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Poor or improper connection of the GPCM Signal Ground circuit may cause this DTC to set.
An open or high resistance in the Ignition 1 Signal circuit may cause the DTC to set.
Poor connections at the battery voltage supply circuit of the GPCM may cause the DTC to set.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Engine running.
All accessories OFF, measure and record the battery voltage at the battery terminals. The voltage should be between 12.6 and 15.0 V. If not between 12.6 and 15.0 V Refer to «Charging System Test»(/chevrolet/express-g2500/2013-2013/remont/charging-system/#battery-charging-system-and-starting-system) . If between 12.6 and 15.0 V
Verify the scan tool GPCM Ignition 1 Signal parameter is between 12.6-15.0 V. If not between 12.6 and 15.0 V Refer to Circuit/System Testing. If between 12.6 and 15.0 V
Glow plugs not commanded ON, verify the scan tool Glow Plug Supply Voltage parameter is 0.0 volts. If not 0.0 volts Refer to Circuit/System Testing. If 0.0 volts
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 DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

Measure and record the voltage between the Battery Positive Voltage circuit at GPCM connector X1 and ground. If voltage is not B+ Repair the open or high resistance in the Battery Positive Voltage circuit. If voltage is B+
Ignition ON.
Glow plugs OFF, test for 0.0 V on the Glow Plug Supply Voltage 1-8 circuits. If greater than 0.0 V Disconnect the Glow Plug Control Module X1 connector and retest the Glow Plug Supply Voltage 1-8 circuits for 0.0 V. NOTE: If a short to voltage is indicated the appropriate glow plug(s) must be inspected for damage. If greater than 0.0 V Test for a short to voltage on the appropriate Glow Plug Supply Voltage circuit, repair as necessary. If 0.0 V Replace the K34 Glow Plug Control Module. If 0.0 V
Ignition ON.
Using a scan tool, verify the following parameters are less than 0.70 ohms: Cylinder 1 Glow Plug Resistance Cylinder 2 Glow Plug Resistance Cylinder 3 Glow Plug Resistance Cylinder 4 Glow Plug Resistance Cylinder 5 Glow Plug Resistance Cylinder 6 Glow Plug Resistance Cylinder 7 Glow Plug Resistance Cylinder 8 Glow Plug Resistance If greater than 0.70 ohms Test the appropriate Glow Plug Supply Voltage circuit for high resistance. If the circuit tests normal replace the appropriate E12 Glow Plug. If less than 0.70 ohms
Ignition OFF.
Disconnect the X2 harness connector at the K34 Glow Plug Control Module.
Ignition ON.
Test for B+ between the Run/Crank Ignition 1 Voltage circuit terminal 33 and ground. If voltage is less than B+ Repair the open, short to ground or high resistance in the Run/Crank Ignition 1 Voltage circuit. If voltage is B+
Test for B+ between the Run/Crank Ignition 1 Voltage circuit terminal 33 and Signal Ground circuit terminal 10. If voltage is less than B+ Repair the open or high resistance in the Signal Ground circuit. If voltage is B+
Test for B+ between the Run/Crank Ignition 1 Voltage circuit terminal 33 and Ground circuit terminal 8. If voltage is less than B+ Repair the open or high resistance in the Ground circuit. If voltage is B+
Replace the K34 Glow Plug Control Module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Glow Plug Replacement - Bank 1»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Glow Plug Replacement - Bank 2»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for GPCM replacement, setup, and programming

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Intake Air Heater Temperature Signal		P154D	P154D

The intake air heater is located at the intake manifold outlet and is used to heat the air before it enters the inner cooler during cold engine operation. The engine control module (ECM) determines when to request the glow plug control module to turn ON and OFF the intake air heater. The glow plug control module controls the intake air heater current by monitoring the feedback circuits of the intake air heater. The intake air heater will only be commanded ON while the engine is running if required by the ECM.

The intake air heater is commanded ON
The engine is running for more than 40 seconds.
Engine coolant temperature is less than 60°C (140°F).

DTC's P0154A, P0154C, or P154D are not set.
Battery volage is between 9-16 V.
The IAH temperature is more than 80°C (176°F) for more than 3 seconds.

DTC P166B is a type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Verify the intake air heater is clear of debris and aftermarket devices. If debris or aftermarket devices were found Repair as necessary. If no debris or aftermarket devices were found
Verify DTC's P0154A, P0154C, or P154D are not set. If another DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If another DTC is not set
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 DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

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

Ignition OFF.
Disconnect the harness connector at the E24 Intake Air Heater.
Ignition ON.
Verify the scan tool Intake Air Heater Temperature Signal Circuit Status parameter displays OK. If parameter does not display OK Test the Intake Air Heater Temperature Signal circuit terminal 1 for an open, short to ground, or short to voltage. If the circuit tests normal, replace the K34 Glow Plug Control Module. If parameter displays OK
Replace the E24 Intake Air Heater.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Intake Air Heater Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for glow plug control module replacement, setup, and programming

The position of the turbocharger vanes is controlled by the engine control module (ECM). The ECM utilizes a turbocharger vane control solenoid valve to control the turbocharger vanes, and a turbocharger vane position sensor to verify the position of the vanes. The ECM will vary the boost dependent upon the load requirements of the engine. The turbocharger vane position sensor provides the ECM with a signal voltage relative to the vane position.

DTC P0045, P0047, P0048, P006E, P007C, P007D, P008F, P0117, P0118, P02E8, P02E9, P0401, P0402, P128E, P140B, P140C, P16A0, P16A1, P16A2, P2228, or P2229 is not set.
The coolant temperature is greater than 70°C (158°F).
The engine speed is between 1,000-1,800 RPM.
The barometric pressure (BARO) is greater than 74.8 kPa (10.85 psi).
The ambient air temperature is greater than -7°C (19.4°F).
The throttle position is less than 5 %.
The turbocharger actuator position sensor offset learning is not active.
The turbocharger vane cleaning/ wiping, procedure is not active.
DTC P168C and P168D run continuously whenever the above conditions are met.

The ECM detects that the difference between actual vane position and desired vane position, over a specified amount of time, is greater than a calibrated threshold.

DTC P168C and P168D are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

A restricted oil supply feed to the turbocharger may cause this DTC to set.

Schematic Reference

Connector End View Reference

Turbocharger System Description

Description and Operation

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool DTC information. Verify DTC P003A, P0045, P0047, P0048, P006E, P006F, P06D2, P2564, or P2565 is not set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.
Engine running, observe the scan tool TC Vane Position Sensor and the Desired TC Vane Position parameters. Increase the TC Vane Position Sensor in 5 % increments from 0-100 % within 20 s then decrease the TC vane position sensor in 5 % increments from 100-0 % within 20 s. The parameters should increase and decrease smoothly and remain within 2 % throughout the entire commanded range.
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.

Inspect the turbocharger for debris, sticking vanes or damage. Refer to «Turbocharger Cleaning and Inspection»(/chevrolet/express-g2500/2013-2013/remont/mechanical/#engine-mechanical-66l-lgh-repair-instructions-off-vehicle__turbocharger-cleaning-and-inspection) . If a condition is found, clean or replace the turbocharger as necessary.
Inspect the Q41 turbocharger vane position control solenoid valve and B112 turbocharger vane position sensor for damage or sticking. If a condition is found, test or replace the affected component as necessary.

Turbocharger Vane Position Control Solenoid Valve

Ignition OFF, disconnect the harness connector at the Q41 turbocharger vane position control solenoid valve.
Measure the resistance across the Q41 turbocharger vane position control solenoid valve terminals. The resistance should be between 3-7 ohms. If greater than the specified range, replace the Q41 turbocharger vane position control solenoid valve.
Test for infinite resistance between each Q41 turbocharger vane position control solenoid valve terminal and the solenoid valve housing. If less than the specified range, replace the Q41 turbocharger vane position control solenoid valve.
Ignition OFF, remove the turbocharger vane position control solenoid valve.
Connect the Q41 turbocharger vane position control solenoid valve harness connector.
Ignition ON, command the TC Vane Pos. Cntrl. Solenoid ON with a scan tool. Depress and hold the CAM follower slightly at the tip of the TC solenoid valve while observing the slot closest to the CAM follower for the spool valve to move to the open position. If the spool valve did not move to the open position, replace the Q41 turbocharger vane position control solenoid valve.

Turbocharger Vane Position Sensor

Remove the B112 turbocharger vane position sensor.
Connect the B112 turbocharger vane position sensor harness connector.
Ignition ON, observe the scan tool TC Vane Position Sensor voltage while slowly depressing the plunger at the end of the B112 turbocharger vane position sensor. The voltage should decrease smoothly from approximately 4.9-0.2 V. If the TC Vane Position Sensor parameter drops out or spikes, replace the B112 turbocharger vane position sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Turbocharger Replacement»(/chevrolet/express-g2500/2013-2013/remont/mechanical/#engine-mechanical-66l-lgh-repair-instructions-on-vehicle)
«Turbocharger Control Solenoid Valve Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Turbocharger Vane Position Sensor Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
If any service has been performed on the turbocharger or on the turbocharger components, a turbocharger relearn must be performed. Refer to «Turbocharger Learn»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__turbocharger-learn) .
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

The glow plug control module has the ability to perform internal diagnostics for voltage and output state of the glow plugs. If the difference between the internal temperature of the glow plug control module and the internal temperature of the intake air heater module is greater than 20°C (68°F), this DTC will set. The glow plug control module will send a message to the engine control module (ECM) to set this DTC.

Engine is running.
Engine off timer is greater than or equal to 28,800 seconds.
Intake air temperature is greater than -7°C (19°F).
Intake air heater pulse width modulation equals 100 percent.
DTC P154D is not set.

The difference between the internal temperature of the glow plug control module and the internal temperature of the intake air heater module is greater than 20°C (68°F).

DTC P16A8 is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Ensure the glow plug control module is clear of any aftermarket devices.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

If you cannot duplicate the conditions, refer to «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures) .
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 DTC sets Refer to Circuit/System Testing. If DTC does not set
All OK.

Note. Verify there are no aftermarket air flow restrictions near the glow plug control module.

Verify there are no other DTCs set. If another DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If another DTC is not set Replace the E24 Intake Air Heater and clear the DTC. Road test the vehicle under the conditions to run the DTC. Verify the DTC does not set. If the DTC sets, replace the K34 Glow Plug Control Module

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Intake Air Heater Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
«Control Module References»(/chevrolet/express-g2500/2013-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for glow plug control module replacement, setup, and programming

The intake air heater has the ability to perform internal diagnostics for the temperature sensor circuit. The intake air heater monitors the internal temperature sensor voltage and if the voltage falls outside the calibrated threshold, the intake air heater sends a message to the glow plug control module (GPCM) and then the GPCM sends a message to the engine control module (ECM) to set the appropriate DTC.

Ignition ON.
The intake air heater battery voltage is greater than 11 V.
DTC P154D is not set.
The DTC runs once per trip at ignition key up.

A fault is detected when the Intake Air Heater internal temperature voltage falls outside the calibrated threshold for greater than 1.15 S.

DTCs P16AA and P16AB are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

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. If DTC resets Refer to Circuit/System Testing. If DTC does not reset
All OK.

Verify there are no other DTCs present. If another DTC is present Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If another DTC is not present Replace the E24 Intake Air Heater .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Intake Air Heater Replacement

The glow plug control module (GPCM) has the ability to perform internal diagnostics for the temperature sensor circuit. The GPCM monitors the internal temperature sensor voltage and If the voltage is less than 0.21 V or greater than 4.94 V. The GPCM will send a message to the engine control module (ECM) to set the appropriate DTC.

Engine running.
The DTC runs continuous when the above condition exists.

A fault is detected when the GPCM temperature sensor voltage falls outside the calibrated threshold for greater than 1.81 seconds.

DTCs P16AD and P16AE are Type B DTCs.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Ignition ON.
Observe the DTC information with a scan tool. Verify there are no other DTCs set. If another DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If another DTC is not set
Replace the K34 Glow Plug Control Module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for glow plug control module replacement, programming, and setup.

The engine control module (ECM) monitors the system with inputs from two exhaust gas temperature (EGT) sensors 1 and 2 and a differential pressure sensor . This diesel particulate filter diagnostic provides a means for monitoring the exhaust particulate filter efficiency. The resistive exhaust flow is monitored to determine if a DPF substrate is missing or a defined DPF failure has occurred. The resistive exhaust flow is calculated from mass air flow and DPF differential pressure. This diagnostic will run after a successful regeneration event has completed. This includes a successful service regeneration event.

DTCs P0101-P0103, P2228, P2229, P2453, P2454, and P2455 are not set.
A regeneration event is active.
Engine speed is greater than 600 RPM for at least 10 s.
Ambient air temperature is greater than -7°C (19°F).
BARO is greater than 75 kPa (11 psi).
Exhaust gas temperature sensor 3 and exhaust gas temperature sensor 4 temperatures are between 500-800°C (932-1472°F).
The DTC runs once a successful regeneration has completed.

The ECM detects that the particulate filter has degraded beyond a calibrated threshold after a successful regeneration has completed.

DTC P2002 is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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

Ignition On.
Verify that DTCs P003A, P0047, P0048, P0101-P0103, P0201-P0208, P0234, P0299, P0300-P0308, P0401, P0402, P046C, P0545, P0546, P2032, P2033, or P2454-P2455 are not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) If none of the DTCs are set
Engine idling and at operating temperature.
Verify very light or no black smoke is visible from the tailpipe while performing several accelerator pedal sweeps by rapidly depressing the accelerator pedal to wide open throttle (WOT) and returning the pedal to the at rest position, allowing the engine to return to idle speed for 5 s. If heavy black smoke is observed Replace the Exhaust Particulate Filter If no heavy black smoke is observed
Verify the following conditions do not exist with the exhaust and DPF system: Any damaged, missing or altered components. Leaks in the exhaust system -Refer to «Exhaust Leakage»(/chevrolet/express-g2500/2013-2013/remont/exhaust/#engine-exhaust-system__exhaust-leakage) . Improper installation-The exhaust differential pressure lines should have a continuous downward gradient, without sharp kinks, from the differential pressure sensor to the particulate filter. Improperly routed B154 Exhaust Pressure Differential sensor lines. Completely restricted differential pressure sensor lines. Disconnected or broken differential pressure sensor lines. If a condition is found Repair as necessary If no condition is found
Verify the following conditions do not exist with the air induction system: Restrictions in the air induction system and the turbocharger system. Leaks in the intake air ducts and the turbocharger ducts. Perform the Induction System Smoke Test in «Charge Air Cooler Diagnosis (Full System Air Leak Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) , «Charge Air Cooler Diagnosis (Induction System Smoke Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) . Cracked or damaged B75B MAF sensor housing. A skewed, stuck in range, or slow responding MAF sensor. Inspect the MAF sensor for contamination. Refer to «DTC P0101»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p0016-to-dtc-p040f) . Inspect for a dirty air filter element. Debris blocking the air sensing filaments of the MAF sensor. If a condition is found Repair as necessary If no condition is found
Test the charge air cooler system for leaks. Perform the Full System Air Leak Test in «Charge Air Cooler Diagnosis (Full System Air Leak Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) , «Charge Air Cooler Diagnosis (Induction System Smoke Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) . If a leak is found Repair as necessary If no leak is found
Test the engine air induction system for leaks. Perform the Induction System Smoke Test in «Charge Air Cooler Diagnosis (Full System Air Leak Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) , «Charge Air Cooler Diagnosis (Induction System Smoke Test)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) . If a leak is found Repair as necessary If no leak is found
Replace the Exhaust Particulate Filter.
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.
Verify the DTC does not set. If the DTC sets A condition with the system still exists If the DTC does not set
All OK.

Perform the Diagnostic Repair Verification after completing the repair.

«Exhaust Particulate Filter Replacement (LGH-35 Series)»(/chevrolet/express-g2500/2013-2013/remont/exhaust/#engine-exhaust-system) , «Exhaust Particulate Filter Replacement (LGH)»(/chevrolet/express-g2500/2013-2013/remont/exhaust/#engine-exhaust-system)
Perform the scan tool «Diesel Particulate Filter (DPF) Regeneration Enable»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__diesel-particulate-filter-dpf-regeneration-enable) , procedure if the scan tool DPF Soot Mass is less than 30 g. If the scan tool DPF Soot Mass is 30 g or greater, perform the «Diesel Particulate Filter (DPF) Service Regeneration»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions) procedure. After completing the service regeneration, perform the following to verify the diagnostic passed: With the transmission is in park, increase the engine speed to wide open throttle for 30 s. Release the accelerator pedal. Verify DTC P2002 does not set. If the DTC sets A condition still exists. If the DTC does not set All OK.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
DEF Dosing Valve High Control	P1048, P2048	P2047	P1049	P202E, P249D, P249E
DEF Dosing Valve Low Control	P1048, P2048	P2047	P2047	P202E, P249D, P249E

The ECM supplies voltage to the reductant injector on the injector high control circuit. The ECM turns ON the reductant injector by grounding the low control circuit of the injector.

It is common for reductant to crystallize over the nozzle of the reductant injector. The crystals will dissolve with use and the reductant injector will resume full functionality. The Reductant Quantity test may need to be performed multiple times to dissolve the crystallized reductant before diagnosing the reductant injector for performance issues.

P202E

DTCs P1048, P1049, P2047, P2048, or P2049 are not set
SCR reductant level not in restriction or empty level state
Engine speed is greater than 600 RPM for at least 10 s.
Battery voltage is greater than 11 V.
Ambient air temperatures is warmer than -20°C (-4°F).
Calculated reductant injector temperature is between -7 to +100°C (19-212°F).
Reductant pressure is between 350-650 kPa (51-94 psi).
The DTC runs continuously once the above conditions are met.

The ECM detects that the commanded state of the driver and the actual state of the reductant injector do not match for 90 injections.

DTC P202E is a Type A DTC.
The ECM inhibits the reductant system when DTC P202E is set.
Service Exhaust Fluid System message is displayed on the driver information center (DIC).

DTC P202E is a Type A DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Component View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Quality)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Level)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Emission Control)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Anti-Tampering)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy)
«Exhaust Aftertreatment System Description»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation)

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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.

Ignition ON.
Verify DTC P1043, P1044, P204B, P204C, P204D, P208A, P208B, P208C, or P208D are not set. If one of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) If none of the DTCs are set
Engine idling at operating temperature for 10 minutes. Road test until the scan tool Exhaust Gas Temperature Sensor 2 parameter is greater than 180°C (356°F). Observe the DTC information with a scan tool. DTC P202E should not set. If the DTC is set Refer to Circuit/System Testing If the DTC is not set
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.
Verify a DTC does not set. If any DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) If no DTC sets
All OK.

Ignition OFF.
Remove the Q61 Emission Reduction Fluid Injector from the exhaust pipe leaving the reductant line and electrical connector connected.
Place the Q61 Emission Reduction Fluid Injector into a suitable container.
Ignition ON.
Command the Reductant System Leak Test ON with a scan tool. Allow the pressure to build for at least 2 minutes. The first 60 s, the system performs a system purge. Observe the scan tool Reductant Pressure sensor parameter. The reading should be between 400-650 kPa (58-94 psi). The Q61 Emission Reduction Fluid Injector should not leak. If a condition is found Replace the Q61 Emission Reduction Fluid Injector. If no condition is found
Perform the «Emission Reduction Fluid Injector Quantity Test»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures) . The tes should pass. If the test does not pass Replace the Q61 Emission Reduction Fluid Injector If the test passes
All OK.

«Emission Reduction Fluid Injector Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
Perform the scan tool Reductant Injector Reset procedure after replacing the Q61 Emission Reduction Fluid Injector.

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
Clear the DTCs.
Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes.
Ignition ON.
Perform the Reductant System Data Reset with a scan tool in order to clear the reductant indicator lamp, if illuminated. If the reductant indicator lamp does not turn OFF A condition with the system still exists If the reductant indicator lamp turns OFF
Perform the «Reductant System Malfunction Service Bay Test»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures__reductant-system-malfunction-service-bay-test) with a scan tool in order to clear the Service Emission System message, if displayed. If the Service Emission System message does not turn OFF A condition with the system still exists If the Service Emission System message turns OFF
All OK.

The reductant level/temperature sensor is a solid-state device that provides the engine control module (ECM) with information on reductant level and temperature. The level/temperature sensor receives system voltage directly from the underhood electrical center and ground through a chassis ground circuit. The level sensor consists of three sensing elements. Reductant level sensor 3 is highest, reductant level sensor 2 is located between sensor 1 and 3. Reductant level sensor 1 is located at low reductant level. Reductant level sensor 3 is located at less than half range of the reductant tank level. The scan tool will display Active when the level sensors are in contact with reductant and Inactive when not in contact with reductant. An integrated temperature sensor monitors reductant temperature. Reductant level and temperature signals are processed within the sensor and supplied to the ECM as serial data messages. The ECM will set a DTC when it detects an invalid level or temperature serial data message from the sensor.

Engine speed is greater than 600 RPM for at least 10 s.
Battery voltage is greater than 11 V.
Ambient air and emission reduction fluid tank temperatures are warmer than -7°C (19°F) - DTC P203B only.
The DTCs run continuously when the above conditions are met.

P203B

The ECM receives a serial data message from the reductant sensor module that the reductant level sensor indications are not plausible.

P203C, P21AA, and P21AF

The ECM receives a serial data message from the reductant sensor module that the emission reduction fluid tank level sensor 1, 2 or 3 voltage is less than 0.17 V for greater than 3 s. A voltage within this range indicates a short to ground.

P203D, P21AB, and P21B0

The ECM receives a serial data message from the reductant sensor module that the emission reduction fluid tank level sensor 1, 2 or 3 voltage is between 3.56-4.74 V for greater than 3 s. A voltage within this range indicates an open circuit. Or
The ECM receives a serial data message from the reductant sensor module that the emission reduction fluid tank level sensor 1, 2 or 3 voltage is greater than 4.74 V for greater than 3 s. A voltage within this range indicates a short to voltage.

DTCs P203C, P203D, P21AA, P21AB, P21AF, and P21B0 are Type A DTCs.
DTC P203B is a Type B DTC.

DTCs P203C, P203D, P21AA, P21AB, P21AF, and P21B0 are Type A DTCs.
DTC P203B is a Type B DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Schematic Reference

Connector End View Reference

Component View Reference

Description and Operation

«Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Quality)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Level)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Emission Control)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy) , «Diesel Exhaust Fluid (DEF) Warning Strategy (Anti-Tampering)»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation__diesel-exhaust-fluid-def-warning-strategy)
«Exhaust Aftertreatment System Description»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-description-and-operation)

Electrical Information Reference

«Circuit Testing»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/chevrolet/express-g2500/2013-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/chevrolet/express-g2500/2013-2013/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.

Ignition On.
Verify DTC UXXXX is not set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If no DTC is set
Engine idling.
Verify DTC P203B is not set. If the DTC is set Replace the B213 Reductant Level Sensor. If the DTC is not set
Ignition ON.
Observe the circuit status parameters listed below with a scan tool: Reductant Level Sensor 1 Circuit Status. Reductant Level Sensor 2 Circuit Status. Reductant Level Sensor 3 Circuit Status. Each parameter should display OK or Incomplete If not the specifed value Replace the B213 Reductant Level Sensor. If the specified value
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.
Verify a DTC does not set. If any DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If no DTC sets
All OK.

«Emission Reduction Fluid Tank Reservoir Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions__emission-reduction-fluid-tank-reservoir-replacement) for B213 Reductant Level Sensor.
«Level and Temperature Emission Reduction Fluid Tank Module Replacement»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-repair-instructions)
Perform the scan tool Reductant System Reset procedure after replacing the B213 Reductant Level Sensor.

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
Clear the DTCs.
Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes.
Ignition ON, command the Reductant System Leak Test ON with a scan tool. Allow the pressure to build for at least 2 minutes. The first 60 s, the system performs a system purge. Observe the scan tool Reductant Pressure sensor parameter. The reading should be between 400-650 kPa (58-94 psi) and there should be no leaks in the system. If not within the specified range or a leak is found A condition with the system still exists If within the specified range and no leak is found
Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes.
Engine idling for 30 s.
Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes.
Ignition ON.
Perform the Reductant System Data Reset with a scan tool in order to clear the reductant indicator lamp, if illuminated. If the reductant indicator lamp does not turn OFF A condition with the system still exists. If the reductant indicator lamp turns OFF
Perform the «Reductant System Malfunction Service Bay Test»(/chevrolet/express-g2500/2013-2013/remont/testing-diagnostics/#engine-controls-and-fuel-66l-lgh-dtc-p204c-to-dtc-p2599-and-diagnostic-information-and-procedures__reductant-system-malfunction-service-bay-test) with a scan tool in order to clear the Service Emission System message, if displayed. If the Service Emission System message does not turn OFF A condition with the system still exists. If the Service Emission System message turns OFF
All OK.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
5 V Reference	P06D2, P204C	P204C	P06D2	P204B
DEF Pressure Sensor Signal	P204C	P204C	P204D	P204B
Low Reference		P204C		P204B

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Reductant pump ON Parameter Normal Range: 425-575 kPa
5 V Reference	0 kPa	0 kPa	0 kPa
DEF Pressure Sensor Signal	0 kPa	0 kPa	750-850 kPa
Low Reference		0 kPa	5-20 kPa

Reductant Pressure

The reductant pressure sensor responds to pressure changes in the reductant system. The engine control module (ECM) supplies 5 V to the reductant pressure sensor on the 5 V reference circuit and provides a ground on the low reference circuit. The reductant pressure sensor provides a signal to the ECM on the sensor signal circuit which is relative to the pressure changes in the reductant system.

Condition for Running the DTC

DTCs P204C or P204D are not set.
Ignition is ON.
Ambient air temperature is greater than -30°C (-22°F).
Exhaust gas temperature sensor 2 is less than 170°C (338° F).
The DTC runs continuously when the above conditions are met.

The ECM detects the difference between the reductant pressure and the BARO pressure is greater than 50 kPa for greater than 1 s.

DTC P204B is a Type A DTC.
The ECM inhibits the reductant system.

DTC P204B is a Type A DTC.

Perform the «Diagnostic System Check - Vehicle»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/chevrolet/express-g2500/2013-2013/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

If the reductant tank temperature is below 11°C (+4°F), the tank is in frozen status. Completely thaw the tank in the shop and warm the fluid in the tank to greater than 0°C (+32°F).

Schematic Reference

Connector End View Reference

Component View Reference