Engine Controls - 6.6l (DTC p0016 to p0237) Chevrolet Cab & Chassis Silverado 3500

Circuit Description

The engine control module (ECM) monitors the crankshaft position (CKP) and the camshaft position (CMP) signals to determine if they are synchronized. If both signals are not observed by the ECM within a narrow time window, the ECM will determine that an error has occurred and DTC P0016 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC P0016 Crankshaft Position (CKP) - Camshaft Position (CMP) Correlation

Conditions for Running the DTC

1. The engine is cranking or running.
2. DTC P0016 runs continuously when the above condition is met.

Conditions for Setting the DTC

When the engine is cranking or running, the cam sensor pulses received by the ECM does not equal 3 in one crankshaft revolution.

Action Taken When the DTC Sets

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

Inspect for the following items

1. A loose CMP sensor causing a variance in the sensor signal
2. Excessive free play or damage of the timing gears
3. The Camshaft Reference Signal Missed parameter will only increment for an intermittent. A constant failure of the CMP sensor will not cause the parameter to increment, but will set DTC P0340.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 3: A condition that sets one of these DTCs may also result in a DTC P0016. Diagnose these codes before continuing with this diagnostic.
2. 5: A loose CMP sensor may result in a DTC P0016. Attempt to tighten the sensor to proper torque specifications. If unable to prevent CMP sensor movement, inspect the cover for damage before replacing the sensor.
3. 6: A cracked CMP sensor or internal breakage may result in DTC P0016. This will not be apparent unless the sensor is removed from the front engine cover.
4. 7: If the CMP sensor appears to be damaged by contact with the camshaft gear, you may need to remove the front engine cover and inspect for excessive camshaft end-play.

DTC P0016

The position of the turbocharger vanes is controlled by the engine control module (ECM). The ECM utilizes a turbocharger vane control solenoid valve and a turbocharger vane position sensor to control the turbocharger vanes. When the engine is not under load, the turbocharger vanes are in an open position, or no boost condition. When the engine is under load, the ECM commands the control solenoid valve to close the turbocharger vanes, thus increasing the boost. The ECM will vary the boost dependent upon the load requirements of the engine. The vane control solenoid valve uses 2 circuits, a control circuit and a low reference circuit. The ECM uses a pulse width modulation on the control circuit to open and control the solenoid valve. The ECM provides a ground on the low reference circuit. If the ECM detects any circuit failure, DTC P0045 will set.

This diagnostic procedure supports the following DTC

DTC P0045 Turbocharger Vane Position Control Solenoid Control Circuit

1. The engine run time is more than 30 seconds.
2. DTC P0045 runs continuously once the above conditions are met.

1. The control module detects that the commanded state of the driver and the actual state of the control circuit do NOT match.
2. The above condition exists for more than 2 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P0045

The position of the turbocharger vanes is controlled by the engine control module (ECM). The ECM utilizes a turbocharger vane control solenoid valve and a turbocharger vane position sensor to control the turbocharger vanes. When the engine is not under load, the turbocharger vanes are in an open position, or no boost condition. When the engine is under load, the ECM commands the control solenoid valve to close the turbocharger vanes, thus increasing the boost. The ECM will vary the boost dependent upon the load requirements of the engine. The vane control solenoid valve uses 2 circuits, a control circuit and a low reference circuit. The ECM uses a pulse width modulation (PWM) on the control circuit to control the solenoid valve. The ECM provides a ground on the low reference circuit. If the ECM detects that the commanded position of the turbocharger vanes does not match the actual position, DTC P0046 will set.

This diagnostic procedure supports the following DTC

DTC P0046 Turbocharger Vane Control Position Performance

1. The ignition is ON.
2. DTC P0046 runs continuously once the above conditions are met.

The ECM detects that the commanded position of the turbocharger vanes does not match the actual position for 1 second.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. If any service has been performed on the turbocharger or on the turbocharger components, a turbocharger relearn must be performed. Failure to perform the turbocharger learn procedure may cause this DTC to set. Refer to «Turbocharger Learn Procedure»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-introduction) .
2. For an intermittent condition, refer to «Intermittent Conditions»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis__intermittent-conditions) .

DTC P0046

The engine control module (ECM) monitors fuel rail pressure (FRP) using the FRP sensor. If the sensor indicates a pressure less than the commanded rail pressure plus a possible transitional overshoot, the ECM will set DTC P0087 for fuel rail pressure too low.

DTC Descriptors

This diagnostic procedure supports the following DTC

DTC P0087 Fuel Rail Pressure (FRP) Too Low

1. DTCs P0192, P0193, P0642 or P0643 are not set.
2. The ignition is ON.

The actual FRP is less than 0.0 MPa at 0-400 RPM.

OR

The actual FRP is less than 22.5 MPa at more than 600 RPM.

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.
3. The ECM will limit fuel injection.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. A restricted fuel supply line may cause DTCs P0087 and P1093 to set at the same time. When ambient temperatures are below 0°C (32°F), the fuel tank pickup screen may be iced over from water in the fuel tank. Refer to «Fuel System Diagnosis»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis) .
2. If power enhancing devices have been attached to the fuel rail pressure sensor circuits, this DTC may set and adversely effect the fuel system components. Refer to «Fuel System Diagnosis - High Pressure Side»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis) .

The numbers below refer to the step numbers on the diagnostic table.

1. 2: If the fuel temperature is high enough to set DTC P0168, the fuel may be thin enough to cause this DTC to set.
2. 3: The engine will not start if the fuel leak is large enough.
3. 5: This step tests for fuel leaks into the engine oil.
4. 6: This step tests for an inaccurate fuel rail pressure sensor.
5. 7: This step tests for a restriction in the fuel system between the fuel injection pump and the fuel tank.
6. 8: This test tests to see if the fuel injection pump is able to supply maximum fuel pressure at idle. The fuel injection pump should be able to create 145-158 MPa at idle. In extreme ambient or fuel temperatures, the fuel injection pump may only be able to generate a pressure at the low end of this range.
7. 9: This step tests for a restriction in the fuel system between the fuel injection pump and the fuel tank that may only cause symptoms at higher engine speed and load conditions.
8. 10: This step tests to see if the fuel rail pressure sensor wiring and ECM are functioning normally.
9. 12: If the vacuum is still too high in the fuel supply system after replacing the fuel filter, there is a restriction in the fuel supply lines or sending unit in the fuel tank.

DTC P0087

The engine control module (ECM) monitors fuel rail pressure (FRP) using the FRP sensor. If the sensor indicates a pressure more than the commanded rail pressure plus a possible transitional overshoot, the ECM will set DTC P0088 for FRP too high.

This diagnostic procedure supports the following DTC

DTC P0088 Fuel Rail Pressure (FRP) Too High

1. DTCs P0192, P0193, P0642 or P0643 are not set.
2. The ignition is ON.

The actual fuel pressure is more than 167 MPa.

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.
3. The control module will limit fuel injection and FRP.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. There are no driveability concerns associated with the FRP regulator unless a DTC is present. The most likely cause of this DTC is a sticking FRP regulator.
2. If the fuel system pressure is actually too high, a fuel knock and smoke condition will exist.

The number below refers to the step number on the diagnostic table.

1. 3: DTC P0090 is a current flow condition in the FRP regulator circuit. This incorrect current draw could lead to incorrect fuel pressure. This hardware condition should be diagnosed before the performance DTC is tested.

DTC P0088

The engine control module (ECM) uses commanded fuel pump flow to determine a desired fuel rail pressure (FRP). The actual fuel pressure is monitored using the FRP sensor. If the FRP sensor indicates a pressure more than 20 MPa greater than desired, DTC P0089 will set.

This diagnostic procedure supports the following DTC

DTC P0089 Fuel Pressure Regulator Performance

1. DTCs P0192, P0193, P0642 or P0643 are not set.
2. The ignition is ON.

1. The difference between the actual FRP and the desired FRP is more than 20 MPa.
2. The commanded fuel pump flow is 100 mm 3 /second or less.

Action Taken When the DTC Sets - California

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

Action Taken When the DTC Sets - Federal

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The MIL will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.
4. The driver information center (DIC), if equipped, may display a message.

Conditions for Clearing the MIL/DTC - California

1. The control module turns OFF the MIL after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Use a scan tool in order to clear the MIL and the DTC.

Conditions for Clearing the DTC - Federal

1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
3. Use a scan tool in order to clear the DTC.

1. There are no driveability concerns associated with the FRP regulator unless a DTC is present. The most likely cause of this DTC is a sticking FRP regulator.
2. If the fuel system pressure is actually too high, a fuel knock and smoke condition will exist.

The number below refers to the step number on the diagnostic table.

1. 3: DTC P0090 is a current flow condition in the FRP regulator circuit. This incorrect current draw could lead to incorrect fuel pressure. This hardware condition should be diagnosed before the performance DTC is tested.

DTC P0089

The engine control module (ECM) supplies power and ground to the fuel rail pressure (FRP) regulator. The ECM monitors current on the circuits to detect a failure. If the current is outside of the expected range, DTC P0090 will set.

This diagnostic procedure supports the following DTC

DTC P0090 Fuel Pressure Regulator Control Circuit

1. The ignition is ON.
2. The commanded FRP regulator current is between 400-1,500 mA.

The FRP regulator circuit current is not between 50-1,600 mA.

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. There are no driveability concerns associated with the FRP regulator unless a DTC is present. The most likely cause of this DTC is a sticking FRP regulator.
2. If the fuel system pressure is actually too high, a fuel knock and smoke condition will exist.

The numbers below refer to the step numbers on the diagnostic table.

1. 7: This step tests for battery voltage through the ECM to the FRP regulator.
2. 8: This step tests for an open control circuit between the ECM and the FRP regulator.
3. 9: This excessive current code can be set by voltage being applied between the ECM and the FRP regulator on the FRP control circuit.

DTC P0090

The mass air flow (MAF) sensor is an air flow meter that measures the amount of air entering the engine. The engine control module (ECM) uses the MAF sensor voltage signal to provide the correct fuel delivery for a reduction in emissions. The ECM uses the MAF sensor signal to control fuel delivery until a calibrated amount of engine air flow is attained. The MAF sensor has an ignition 1 voltage circuit, a signal circuit and a low reference circuit. The MAF sensor produces an output voltage based on the inlet air flow through the air induction system. This output voltage will display on the scan tool as a voltage parameter and as a grams per second (g/s) parameter. The ECM will calculate a predicted MAF value. The ECM compares the actual MAF sensor voltage signal to the predicted MAF value. This comparison will determine if the signal is stuck, or is too low or too high for a given operating condition. If the ECM detects that the actual MAF sensor voltage signal is not within a predetermined range of the calculated MAF value, DTC P0101 sets.

This diagnostic procedure supports the following DTC

DTC P0101 Mass Air Flow (MAF) Sensor Performance

1. DTC P0016, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0234, P0237, P0238, P0299, P0335, P0336, P0340, P0341, P0370, P0374, P2227, P2228, P2229 are not set.
2. The ignition 1 signal is between 9-18 volts.
3. The intake air temperature (IAT) is more than -20°C (-4°F).
4. The engine speed is less than 3,500 RPM.
5. The engine speed is steady within a range of 50 RPM.
6. The engine coolant temperature (ECT) is more than -20°C (-4°F).
7. The above conditions are met for more than 2 seconds.
8. DTC P0101 runs continuously within the enabling conditions.

The ECM detects that the MAF sensor voltage signal is not within a predetermined range of the calculated MAF value for more than 12 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, if equipped, may display a message.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Use a scan tool in order to clear the MIL and the DTC.

1. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Use a scan tool in order to clear the MIL and the DTC.

1. Any unmetered air that enters the engine downstream of the MAF sensor may cause this DTC to set.
2. A short between the signal circuit of the MAF sensor and the signal circuit of the intake air temperature (IAT) sensor will skew the MAF sensor higher than normal at idle and less than normal at higher air flows.
3. A malfunctioning MAF sensor can cause excessive engine emissions.
4. The MAF display should increase from 24-50 g/s at idle to 320 g/s or more at the 2-3 shift during a wide-open throttle (WOT) acceleration. If not, inspect for a restriction in the induction system or the exhaust system.
5. If the vehicle condition is intermittent, refer to «Inducing Intermittent Fault Conditions»(ref-197325-S26763912192005101100000) and «Intermittent Conditions»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis__intermittent-conditions) .

DTC P0101

The mass air flow (MAF) sensor is an air flow meter that measures the amount of air entering the engine. The engine control module (ECM) uses the MAF sensor voltage signal to provide the correct fuel delivery for a reduction in emissions. The ECM uses the MAF sensor signal to control fuel delivery until a calibrated amount of engine air flow is attained. The MAF sensor has an ignition 1 voltage circuit, a signal circuit and a low reference circuit. The MAF sensor produces an output voltage based on the inlet air flow through the air induction system. This output voltage will display on the scan tool as a voltage parameter and as a grams per second (g/s) parameter. If the ECM detects that the actual MAF sensor voltage signal is less than the possible range of a normally operating sensor DTC P0102 sets.

This diagnostic procedure supports the following DTC

DTC P0102 Mass Air Flow (MAF) Sensor Circuit Low Voltage.

1. The engine is running for more than 2 seconds.
2. The engine speed is more than 500 RPM.
3. The ignition 1 signal is more than 9 volts.
4. The above conditions are present for more than 3 seconds.
5. DTC P0102 runs continuously within the enabling conditions.

The ECM detects that the MAF sensor voltage signal is less than 0.42 volt for more than 6 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. The MAF Sensor parameter should increase from 24-50 g/s at idle to 320 g/s or more at the 2-3 shift during a wide-open throttle (WOT) acceleration. If not, inspect for a restriction in the induction system or the exhaust system.
2. If the condition is intermittent, refer to «Intermittent Conditions»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis__intermittent-conditions) and «Inducing Intermittent Fault Conditions»(ref-197325-S26763912192005101100000) in Wiring Systems.

DTC P0102

The mass air flow (MAF) sensor is an air flow meter that measures the amount of air entering the engine. The engine control module (ECM) uses the MAF sensor voltage signal to provide the correct fuel delivery for a reduction in emissions. The ECM uses the MAF sensor signal to control fuel delivery until a calibrated amount of engine air flow is attained. The MAF sensor has an ignition 1 voltage circuit, a signal circuit and a low reference circuit. The MAF sensor produces an output voltage based on the inlet air flow through the air induction system. This output voltage will display on the scan tool as a voltage parameter and as a grams per second (g/s) parameter. If the ECM detects that the actual MAF sensor voltage signal is more than the possible range of a normally operating sensor DTC P0103 sets.

This diagnostic procedure supports the following DTC

DTC P0103 Mass Air Flow (MAF) Sensor Circuit High Voltage.

1. DTC P0112, P0113 are not set.
2. The engine is running for more than 2 seconds.
3. The engine speed is between 500-2,500 RPM.
4. The ignition 1 signal is more than 9 volts.
5. The IAT Sensor parameter is more than -7°C (19°F).
6. The above conditions are met for more than 3 seconds.
7. DTC P0103 runs continuously within the enabling conditions.

The ECM detects that the MAF sensor voltage signal is more than 4.5 volts for more than 6 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P0103

The intake air temperature (IAT) sensor is a variable resistor. The IAT sensor has a signal circuit and a low reference circuit. The IAT sensor measures the temperature of the air entering the engine. The engine control module (ECM) supplies 5 volts to the IAT signal circuit, and a ground for the IAT low reference circuit. When the IAT sensor is cold, the sensor resistance is high. When the air temperature increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the IAT signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the IAT signal circuit. If the ECM detects an excessively low IAT signal voltage, indicating a high temperature, DTC P0112 sets.

This diagnostic procedure supports the following DTC

DTC P0112 Intake Air Temperature (IAT) Sensor Circuit Low Voltage

1. DTC P0116, P0117, P0118 are not set.
2. The engine is running.
3. The ECT Sensor parameter is between 20-50°C (68-122°F).
4. DTC P0112 runs continuously within the enabling conditions.

The IAT Sensor parameter is more than 148°C (298°F) for more than 10 seconds. This is equal to less than 0.24 volts on the IAT signal circuit as measured by the ECM.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P0112

The intake air temperature (IAT) sensor is a variable resistor. The IAT sensor has a signal circuit and a low reference circuit. The IAT sensor measures the temperature of the air entering the engine. The engine control module (ECM) supplies 5 volts to the IAT signal circuit, and a ground for the IAT low reference circuit. When the IAT sensor is cold, the sensor resistance is high. When the air temperature increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the IAT signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the IAT signal circuit. If the ECM detects an excessively high IAT signal voltage, indicating a low temperature, DTC P0113 sets.

This diagnostic procedure supports the following DTC

DTC P0113 Intake Air Temperature (IAT) Sensor Circuit High Voltage

1. The engine is running for more than 15 minutes.
2. DTC P0113 runs continuously within the enabling conditions.

The IAT Sensor parameter is less than -39°C (-38°F) for more than 10 seconds. This is equal to more than 4.86 volts on the IAT signal circuit as measured by the ECM.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P0113

The engine coolant temperature (ECT) sensor is a variable resistor that measures the temperature of the engine coolant. The engine control module (ECM) supplies 5 volts to the signal circuit and a ground for the low reference circuit. When the engine coolant temperatures are low, the resistance is high. When the engine coolant temperatures are high the resistance is low. The ECM uses this high side coolant rationality test to determine if the ECT input is skewed high. The ECM will record the amount of time the engine is OFF. At restart the ECM will compare the temperature difference between the ECT and intake air temperature (IAT). Before failing this diagnostic, the ECM will perform the calculation to determine the presence of a block heater. If the temperature difference is not within the calculated range, after the predetermined engine OFF time, DTC P0116 sets.

This diagnostic procedure supports the following DTC

DTC P0116 Engine Coolant Temperature (ECT) Sensor Performance

1. DTCs P0112, P0113, P0117, P0118, P0500, P2610 are not set.
2. The ignition is ON.
3. The start-up IAT is more than 15°C (59°F).
4. The vehicle has a minimum engine OFF time of 10 hours.
5. DTC P0116 runs once per drive cycle within the enabling conditions.

If the ECM detects a start-up temperature difference between the ECT sensor and the IAT sensor of more than 5°C (9°F), then the vehicle must be driven for more than 400 seconds over 24 km/h (15 mph) and the engine speed must be more than 600 RPM. If the IAT sensor temperature decreases more than 5°C (9°F) then a block heater is detected and the test is aborted. If the IAT sensor temperature does not decrease, then a block heater was not detected and DTC P0116 sets.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The numbers below refer to the step numbers on the diagnostic table.

1. 7: A snapshot is the quickest method to capture the data before it changes.
2. 8: An IAT sensor that is skewed low can cause this DTC to set.
3. 10: This step will determine if high resistance has caused this DTC to set.
4. 12: A high resistance short from the signal circuit to the low reference circuit can cause this DTC to set.

DTC P0116

The engine coolant temperature (ECT) sensor is a variable resistor that measures the temperature of the engine coolant. The engine control module (ECM) supplies 5 volts to the ECT signal circuit, and a ground for the ECT low reference circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the ECT signal circuit. If the ECM detects an excessively low ECT signal voltage, which is a high temperature indication, DTC P0117 sets.

This diagnostic procedure supports the following DTC

DTC P0117 Engine Coolant Temperature (ECT) Sensor Circuit Low Voltage

1. The ignition is ON.
2. DTC P0117 runs continuously within the enabling condition.

The ECM detects that the ECT Sensor parameter is more than 148°C (298°F) for more than 10 seconds. This is equal to less than 0.24 volts on the ECT signal circuit as measured by the ECM.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P0117

The engine coolant temperature (ECT) sensor is a variable resistor that measures the temperature of the engine coolant. The engine control module (ECM) supplies 5 volts to the ECT signal circuit and a ground for the ECT low reference circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the ECT signal circuit. If the ECM detects an excessively high ECT signal voltage, which is a low temperature indication, DTC P0118 sets.

This diagnostic procedure supports the following DTC

DTC P0118 Engine Coolant Temperature (ECT) Sensor Circuit High Voltage

1. The engine has been running for more than 8 minutes.
2. DTC P0118 runs continuously within the enabling condition.

The ECT sensor temperature is less than -39°C (-38°F) for more than 10 seconds. This is equal to more than 4.76 volts on the ECT signal circuit as measured by the ECM.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. If a short to a separate 5-volt source occurs, this DTC will set.
2. A skewed sensor could result in poor driveability conditions. Refer to «Temperature vs Resistance»(ref-197340-S13610010342005101100000) .
3. After starting the engine, the ECT should rise steadily, then stabilize when the thermostat opens.
4. If the condition is suspected of being intermittent, refer to «Intermittent Conditions»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis__intermittent-conditions) and «Inducing Intermittent Fault Conditions»(ref-197325-S26763912192005101100000) in Wiring Systems.

DTC P0118

The engine control module (ECM) uses this diagnostic to determine if the engine coolant temperature (ECT) has reached the minimum calibrated thermostat regulating temperature. The ECM supplies 5 volts to the ECT signal circuit and a ground for the ECT low reference circuit. The ECM monitors the temperature of the coolant by using the input received from the ECT sensor. The ECM calculates the amount of fuel burned since start-up to determine if the vehicle has been driven within the conditions that would allow the engine coolant to heat up normally to the thermostat regulating temperature. If the coolant temperature does not increase normally, or does not reach the regulating temperature of the thermostat, the engine is considered not warm enough for stable low emission operation. Additionally other diagnostics that use engine coolant temperature as enabling criteria, may not run when expected.

If the ECM detects that the calibrated amount of fuel has been burnt and the ECT has not reached the minimum calibrated temperature DTC P0128 sets.

This diagnostic procedure supports the following DTC

DTC P0128 Engine Coolant Temperature (ECT) Below Thermostat Regulating Temperature

1. DTCs P0112, P0113, P0116, P0117, P0118, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0611, P0612, P1223, P1226, P1229, P1232, P1235, P1238, P1241, or P1244 are not set.
2. The engine coolant startup temperature is less than 51°C (124°F).
3. The ambient air temperature is more than -7°C (+19°F).
4. The engine run time is more than 925 seconds.
5. The fuel burned since startup is more than 8.5 million cubic millimeters.
6. The total idle time is less than 300 seconds.
7. DTC P0128 will only run once per ignition cycle until a Pass, Fail or Disable condition exists. OR
8. DTCs P0112, P0113, P0116, P0117, P0118, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0611, P0612, P1223, P1226, P1229, P1232, P1235, P1238, P1241, or P1244 are not set.
9. The engine coolant startup temperature is between 51-65°C (124-149°F).
10. The ambient air temperature is more than -7°C (+19°F).
11. The engine run time is more than 500 seconds.
12. The fuel burned since startup is more than 5 million cubic millimeters.
13. The total idle time is less than 150 seconds.
14. DTC P0128 will only run once per ignition cycle until a Pass, Fail or Disable condition exists.

The ECM detects the following

1. The calibrated amount of engine run time has been met.
2. The calibrated amount of fuel has been burnt.
3. The calibrated ECT of 72°C (162°F) has not been met.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTC P0128 is designed to detect a faulty thermostat.
2. A skewed low ECT sensor can cause a DTC P0128 to set.
3. If an intermittent condition is suspected refer to «Inducing Intermittent Fault Conditions»(ref-197325-S26763912192005101100000) in Wiring Systems and «Intermittent Conditions»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis__intermittent-conditions) .

DTC P0128

The fuel temperature sensor is a thermistor type sensor. The engine control module (ECM) supplies 5 volts and a ground circuit to the sensor. When the ECM detects a fuel temperature sensor above a pre-determined value, a type C code, no malfunction indicator lamp (MIL) sets. A fuel cooler located in front of the fuel tank is used to help keep the fuel temperature at an acceptable limit.

This diagnostic procedure supports the following DTC

DTC P0168 Engine Fuel Over-Temperature

1. The ignition is ON.
2. DTC P0168 runs continuously within the enabling conditions.

The fuel temperature sensor is above 122°C (252°F) for more than 5 seconds.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, if equipped, may display a message.

Conditions for Clearing the DTC

1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

The numbers below refer to the step numbers on the diagnostic table.

1. 2: This step inspects for a condition in the fuel cooler that could cause the fuel temperature sensor to increase above the pre-determined specification due to a lack of cooler efficiency.
2. 5: This step tests for a voltage above or below the 5 volts supplied by the ECM.

DTC P0168

The fuel temperature sensor is a thermistor. The engine control module (ECM) supplies the fuel temperature sensor a reference 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 supplied voltage cold and decreases the signal voltage as the sensor warms. The control module monitors the fuel temperature sensor signal circuit in order to calculate the temperature of the fuel entering the engine.

This diagnostic procedure supports the following DTC

DTC P0181 Fuel Temperature Sensor Performance

1. DTC P0112, P0113, P0182, P0183, P0500, P2610 are not set.
2. The engine must be turned OFF for 10 hours or longer.
3. The start-up intake air temperature (IAT) is more than 15°C (59°F).
4. DTC P0181 will only run once per ignition cycle until a Pass, Fail, or Disable conditions exists.

1. The fuel temperature and the ECT are more than 9.75°C (18°F) of each other at start-up.
2. The IAT has dropped less than 5.25°C (10°F) after running more than 400 seconds above 24 km/h (15 mph).

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The numbers below refer to the step numbers on the diagnostic table.

1. 2: This step determines if the IAT sensor reading is reading within a normal range. If the reading is outside of the specification, the IAT sensor may have a fault in the sensor or circuit.
2. 3: This step determines if the fault is present at the time of diagnosis.
3. 13: Reprogram the replacement ECM. Refer to the latest techline information for ECM programming.

DTC P0181

The fuel temperature sensor is a thermistor. The engine control module (ECM) supplies the fuel temperature sensor a reference 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 supplied voltage cold and decreases the signal voltage as the sensor warms. The control module monitors the fuel temperature sensor signal circuit in order to calculate the temperature of the fuel entering the engine. If the ECM detects an excessively low fuel temperature signal voltage, a high temperature indication, this DTC will set.

This diagnostic procedure supports the following DTC

DTC P0182 Fuel Temperature Sensor Circuit Low Voltage

1. DTC P0116, P0117, P0118, P0128 are not set.
2. The engine is running.
3. The engine coolant temperature is less than 60°C (140°F).
4. The ignition voltage is more than 7 volts.
5. DTC P0182 runs continuously within the enabling conditions.

The fuel temperature sensor is more than 129.75°C (265.55°F) for 2 seconds.

OR

The fuel temperature sensor voltage is less than 0.24 volts for 2 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. After starting a cold engine, the fuel temperature should be within a few degrees of the intake air temperature (IAT) sensor.
2. Use the Temperature vs. Resistance table in order to test the fuel temperature sensor at various temperature levels in order to evaluate the possibility of a skewed sensor. A skewed sensor could result in poor driveability concerns.
3. If the condition is suspected of being an intermittent, refer to «Testing for Intermittent Conditions and Poor Connections»(ref-197325-S02683201702005101100000) in Wiring Systems.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: If DTC P0182 can only be repeated by duplicating the Failure Records, refer to Temperature vs Resistance. The table may be used to test the fuel temperature sensor at various temperatures in order to evaluate the possibility of a shifted sensor that may be shorted above or below a certain temperature. If this is the case, replace the fuel temperature sensor. If the fuel temperature sensor appears to be OK, the malfunction is intermittent. Refer to Diagnostic Aids.
2. 5: When testing fuel temperature sensor signal circuit for a short to ground, you may need to inspect for continuity between all other engine control module circuits.

DTC P0182

The fuel temperature sensor is a thermistor. The engine control module (ECM) supplies the fuel temperature sensor a reference voltage of 5 volts on the signal circuit, and also provides a ground circuit to the sensor. When the fuel temperature sensor is cold, the resistance is high. The fuel temperature sensor signal voltage remains near the supplied voltage cold, and decreases the signal voltage as the sensor warms. The control module monitors the fuel temperature sensor signal circuit in order to calculate the temperature of the fuel entering the engine. If the ECM detects an excessively high fuel temperature sensor voltage, a low temperature indication, this DTC will set.

This diagnostic procedure supports the following DTC

DTC P0183 Fuel Temperature Sensor High Voltage

The vehicle has been driven for more than 8 minutes.

1. The fuel temperature sensor is less than -30°C (-22°F) for 2 seconds.
2. DTC P0183 runs continuously within the above enabling conditions.

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. If a short to a separate 5-volt source occurs, this DTC may set. If this is the condition, a continuity test to all other ECM circuits will be necessary in order to diagnose the specific circuit.
2. After starting a cold engine, the fuel temperature sensor should be within a few degrees of the intake air temperature (IAT) reading.
3. Use the Temperature vs. Resistance table to test the fuel temperature sensor at various temperature levels, and to evaluate the possibility of a skewed sensor.
4. If the condition is suspected of being intermittent, refer to «Intermittent Conditions»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis__intermittent-conditions) .

The numbers below refer to the step numbers on the diagnostic table.

1. 3: If DTC P0183 can only be repeated by duplicating the Failure Records, refer to the Temperature vs Resistance table. The table may be used to test the fuel temperature sensor at various temperatures to evaluate the possibility of a shifted sensor that may be shorted above or below a certain temperature. If this is the case, replace the fuel temperature sensor. If the fuel temperature sensor appears to be OK, the malfunction is intermittent. Refer to Diagnostic Aids.
2. 4: This step tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.

DTC P0183

The engine control module (ECM) monitors the fuel rail pressure (FRP) via a FRP sensor. When the fuel rail pressure is high the signal voltage is high. When the FRP is low the signal voltage is low. If the FRP is not above the lower limit for the sensor, DTC P0192 will set.

This diagnostic procedure supports the following DTC

DTC P0192 Fuel Rail Pressure (FRP) Sensor Circuit Low Voltage

1. DTCs P0642 or P0643 are not set.
2. The ignition is ON.
3. DTC P0192 runs continuously within the enabling conditions.

The ECM detects the signal circuit is less than 1.2 MPa for more than 1 second.

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: This step tests for the proper operation of the circuit in the low voltage range.
2. 4: This step tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.

DTC P0192

The engine control module (ECM) monitors the fuel rail pressure (FRP) via a FRP sensor. When the FRP is high, the signal voltage is high. When the FRP is low, the signal voltage is low. If the fuel rail pressure is above the upper limit for the sensor, DTC P0193 will set.

This diagnostic procedure supports the following DTC

DTC P0193 Fuel Rail Pressure (FRP) Sensor Circuit High Voltage

1. DTC P0642 or P0643 is not set.
2. The ignition is ON.
3. The system is not in Power down mode.

The ECM detects the signal circuit is more than 175 MPa.

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.
3. The control module limits fuel injection and FRP.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P0193

The fuel injection control module (FICM) supplies high voltage to each fuel injector on the injector supply voltage circuits. The FICM enables each fuel injector by grounding the command circuit between the FICM and the fuel injector. The FICM monitors the status of the injector supply voltage circuits and the fuel injector command circuits. When a fuel injector circuit condition is detected by the FICM, all of the fuel injectors on the affected injector supply voltage circuit will be disabled. If a circuit condition is detected on a fuel injector circuit for cylinders 1, 4, 6, or 7, DTCs P0201, P0204, P0206, P0207 will set, along with DTC P2146. If a circuit condition is detected on a fuel injector circuit for cylinders 2, 3, 5, or 8, DTCs P0202, P0203, P0205, P0208 will set, along with DTC P2149.

This diagnostic procedure supports the following DTCs

1. DTC P0201 #1 Injector Drive Fault
2. DTC P0202 #2 Injector Drive Fault
3. DTC P0203 #3 Injector Drive Fault
4. DTC P0204 #4 Injector Drive Fault
5. DTC P0205 #5 Injector Drive Fault
6. DTC P0206 #6 Injector Drive Fault
7. DTC P0207 #7 Injector Drive Fault
8. DTC P0208 #8 Injector Drive Fault

1. DTCs U0073 and U0105 are not set.
2. The engine is running.
3. The charging system voltage is between 6-18 volts.

1. The FICM detects an incorrect current on a fuel injector circuit.
2. The condition exists for less than 1 second.

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.
3. The control module disables the set of fuel injectors that have a concern.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The numbers below refer to the step numbers on the diagnostic table.

1. 2: This step verifies that the condition is not intermittent.
2. 4: This step determines which set of fuel injectors the circuit condition is affecting. If DTC P2146 is set, then a condition exists on cylinders 1, 4, 6, or 7. If DTC P2149 is set, then a condition exists on cylinders 2, 3, 5, or 8.
3. 5: This step tests if a ground is constantly being applied to the fuel injectors.
4. 6: This step isolates which circuit is causing the condition. If the DMM displays OL when an injector connector is disconnected, test the affected circuits for a short to ground.
5. 7: This step tests for an open circuit. If the DMM displays OL on all of the fuel injector circuits, the injector supply voltage circuit is open.
6. 8: This step tests for an open circuit. If the DMM displays OL on one of the fuel injector circuits, the fuel injector command circuit is open.
7. 9: This step tests for excessive resistance in a fuel injector circuit.
8. 10: This step is testing for a short between the injector supply voltage circuit and the fuel injector command circuit. If the resistance of the circuits is less than 0.3 ohms, test for a short between the circuits. If a short cannot be found, the fuel injector may be the cause of the condition. The normal fuel injector resistance is between 0.3-0.4 ohms.
9. 11: This step tests for a short to voltage on a fuel injector circuit. If the DMM displays battery voltage, a short to voltage is the cause of the condition.
10. 12: This step isolates which circuit is causing the condition. If the DMM display changes to 0 volts when an injector connector is disconnected, test the disconnected circuits for a short to voltage.
11. 13: This step tests if a ground is constantly being applied to the fuel injectors.
12. 14: This step isolates which circuit is causing the condition. If the DMM displays OL when an injector connector is disconnected, test the affected circuits for a short to ground.
13. 15: This step tests for an open circuit. If the DMM displays OL on all of the fuel injector circuits, the injector supply voltage circuit is open.
14. 16: This step tests for an open circuit. If the DMM displays OL on one of the fuel injector circuits, the fuel injector command circuit is open.
15. 17: This step tests for excessive resistance in a fuel injector circuit.
16. 18: This step is testing for a short between the injector supply circuit and the fuel injector command circuit. If the resistance of the circuits is less than 0.3 ohms, test for a short between the circuits. If a short cannot be found, the fuel injector may be the cause of the condition. The normal fuel injector resistance is between 0.3-0.4 ohms.
17. 19: This step tests for a short to voltage on a fuel injector circuit. If the DMM displays battery voltage a short to voltage is the cause of the condition.
18. 20: This step isolates which circuit is causing the condition. If the DMM display changes to 0 volts when an injector connector is disconnected, test the disconnected circuits for a short to voltage.

DTC P0201-P0208

The boost pressure sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by turbocharger output, engine speed, accelerator pedal input, air temperature, and barometric pressure (BARO). A diaphragm within the boost pressure sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The sensor translates this action into electrical resistance. The boost pressure sensor wiring includes 3 circuits. The engine control module (ECM) supplies a regulated 5 volts to the sensor on a 5-volt reference circuit. The ECM supplies a ground on a low reference circuit. The boost pressure sensor provides a signal voltage to the ECM, relative to pressure, on the boost pressure sensor signal circuit. The ECM converts the signal voltage input to a pressure value. Under normal operation the lowest pressure that can exist in the intake manifold is equal to the BARO. This occurs when the vehicle is operated at idle or when the ignition is on while the engine is off. Under these conditions, the ECM uses the boost pressure sensor to aid in diagnosis of the BARO sensor. The highest manifold pressures occur when the turbocharger output is high. Manifold pressure can range from 58 kPa (8 psi) when pressures are low to more than 240 kPa (34 psi) when pressures are high, depending on the BARO. The boost pressure sensor has a range of 33 kPa (4 psi) to 255 kPa (36 psi). The ECM also uses the boost pressure sensor to provide engine overboost protection. The ECM calculates a predicted value for the boost pressure sensor. The ECM then compares the predicted value to the sensor input. If the ECM detects that the boost pressure sensor input is above the predicted range, this DTC will set.

This diagnostic procedure supports the following DTC

DTC P0234 Turbocharger Engine Overboost

1. DTC P0238 is not set.
2. The engine speed is between 500 RPM and 3,600 RPM.
3. DTC P0234 runs continuously within the enabling conditions.

The measured boost pressure is above the expected range by 35 kPa or more for 12 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Any changes to the induction system or exhaust system, such as the installation of aftermarket parts, may cause this DTC to set.
2. If the condition is intermittent, refer to «Intermittent Conditions»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis__intermittent-conditions) .

DTC P0234

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

Under normal operation, the lowest pressure that can exist in the intake manifold is equal to the BARO. This occurs when the vehicle is operating at idle or when the ignition is ON, while the engine is OFF. Under these conditions, the ECM uses the boost pressure sensor to aid in diagnosis of the BARO sensor. The highest manifold pressures occur when the turbocharger output is high. Manifold pressure can range from 58 kPa (8 psi) when pressure are low, to more than 240 kPa (34 psi) when pressures are high, depending on the BARO. The boost pressure sensor has a range of 33-255 kPa (4-36 psi). The ECM also uses the boost pressure sensor to provide engine overboost protection. The ECM monitors the boost pressure sensor signal for pressure outside of the normal range. If the ECM detects a boost pressure sensor signal pressure that is excessively low, DTC P0237 sets.

This diagnostic procedure supports the following DTC

DTC P0237 Turbocharger Boost Sensor Circuit Low Voltage

1. The engine is running.
2. The ignition voltage is more than 7 volts.
3. DTC P0237 runs continuously within the enabling conditions.

The boost pressure is less than 37 kPa (5 psi) for 2 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
3. The ECM limits fuel delivery.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P0237

See also:
• Engine Controls Schematics
• Engine Control Module (ECM) Connector End Views
• Engine Controls Connector End Views
• Intermittent Conditions
• Engine Front Cover Replacement
• Camshaft Replacement
• Symptoms - Engine Mechanical
• Turbocharger Cleaning and Inspection
• Fuel System Diagnosis
• Fuel in Engine Oil
• Special Tools
• DTC P1093
• DTC P0405
• Exhaust Gas Recirculation (EGR) System Cleaning
• DTC P2229
• DTC P0090