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Engine Controls - 6.6l (DTC p0653 to p2277) Chevrolet Cab & Chassis Silverado 3500

Testing & Diagnostics ~9533 words

Circuit Description

The engine control module (ECM) provides 5 volts to the following sensors

  1. The boost sensor
  2. The accelerator pedal position (APP) sensor 2
  3. The turbocharger vane position sensor
  4. The A/C refrigerant pressure sensor
  5. The barometric pressure (BARO) sensor

These 5-volt reference circuits are independent of each other outside the ECM, but are bussed together inside the ECM. Therefore, a circuit condition on one sensor 5-volt reference circuit may affect the other sensor 5-volt reference circuits. The ECM monitors the voltage on the 5-volt reference circuit. If the ECM detects a high voltage condition, DTC P0653 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC P0653 5-Volt Reference 2 Circuit High Voltage

Conditions for Running the DTC

  1. The ignition is ON.
  2. DTC P0653 runs continuously.

Conditions for Setting the DTC

  1. The ECM detects the 5-volt reference circuit 2 voltage is more than 5.2 volts.
  2. The above condition is present for 2 seconds.

Action Taken When the DTC Sets

  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.

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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Turn ON the ignition, with the engine OFF. Observe the 5-Volt Reference 2 parameter with a scan tool. Is the 5-Volt Reference 2 parameter more than the specified value?5.2 VGo to Step 3Go to Intermittent Conditions
3Test each 5-volt reference 2 circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 6Go to Step 4
4Test the following sensor signal circuits for a short to voltage: The boost sensor signal circuit The A/C pressure sensor signal circuit The barometric pressure (BARO) sensor signal circuit The turbocharger vane position sensor signal circuit-Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 6Go to Step 5
5Replace the engine control module (ECM). Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 6
6Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 7
7Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P0653

The glow plug controller has the ability to perform internal diagnostics for voltage and output state of the glow plugs. If the glow plug controller senses an open in the main battery supply to the glow plug controller, or a condition with any of the glow plug driver circuits, the glow plug controller will send an error message to the engine control module (ECM).

This diagnostic procedure supports the following DTC

DTC P0670 Glow Plug Module Control Circuit

  1. DTC U0073 or U0106 is not set.
  2. The ignition is ON.
  3. DTC P0670 runs continuously.

The glow plug controller detects an open to the main battery supply for the glow plugs, or an open in all 8 glow plug circuits for less than 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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 3Go to Intermittent Conditions
3Is DTC P0671-P0678 set?Go to Step 4Go to Step 5
4IMPORTANT: The DMM and test leads must be calibrated to 0 ohms in order to prevent misdiagnosis. Perform this test with the DMM. Refer to the DMM User Manual for calibration procedure. Turn OFF the ignition. Disconnect the glow plug controller harness connector. Measure the resistance from the ground circuit at the glow plug controller harness connector and a good ground on the engine with a DMM. Does the DMM display a resistance below the specified value?1 ohmsGo to Step 6Go to Step 7
5Turn OFF the ignition. Disconnect the main battery circuit from the glow plug controller. Probe the main battery circuit with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 6Go to Step 8
6Test for an intermittent and for a poor connection at the harness connector of the glow plug controller. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 10
7Repair the ground circuit of the glow plug harness between the glow plug controller and the engine ground for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 9
8Repair the open or the short to ground in the battery positive voltage circuit between the glow plug controller and the battery. Did you complete the repair?Go to Step 11
9Replace the glow plugs. Refer to Glow Plug Replacement - Bank 1 and Glow Plug Replacement - Bank 2 . Did you complete the replacement?Go to Step 11
10Replace the glow plug controller. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 11
11Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 12
12Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK
IMPORTANT
The DMM and test leads must be calibrated to 0 ohms in order to prevent misdiagnosis. Perform this test with the DMM. Refer to the DMM User Manual for calibration procedure.

DTC P0670

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

DTC Descriptors

This diagnostic procedure supports the following DTCs

  1. DTC P0671 Glow Plug 1 Control Circuit
  2. DTC P0672 Glow Plug 2 Control Circuit
  3. DTC P0673 Glow Plug 3 Control Circuit
  4. DTC P0674 Glow Plug 4 Control Circuit
  5. DTC P0675 Glow Plug 5 Control Circuit
  6. DTC P0676 Glow Plug 6 Control Circuit
  7. DTC P0677 Glow Plug 7 Control Circuit
  8. DTC P0678 Glow Plug 8 Control Circuit
  1. DTC U0073 or U0106 are not set.
  2. The ignition is ON.
  3. DTC P0671-P0678 runs continuously.

The glow plug controller detects an open or a short to ground in the glow plug circuit for less than 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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Is DTC P0670 set?Go to DTC P0670Go to Step 3
3Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition. Turn ON the ignition, with the engine 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. Did the DTC fail this ignition?Go to Step 4Go to Intermittent Conditions
4Turn ON the ignition, with the engine OFF. Probe the terminal on the affected glow plug, with an unpowered test lamp connected to the ground. IMPORTANT: The glow plugs can only be commanded ON once per ignition cycle. Turn the ignition OFF and ON to command the glow plugs ON each time with a scan tool. Command the glow plugs ON, with a scan tool. Does the test lamp illuminate with the glow plugs commanded ON?Go to Step 5Go to Step 6
5Turn OFF the ignition. Disconnect the glow plug connector at the affected glow plugs. Probe the terminal on the glow plug with an unpowered test lamp connected to battery voltage. Does the test lamp illuminate?Go to Step 8Go to Step 11
6IMPORTANT: If a glow plug control circuit is shorted to 12 volts, the glow plug will be damaged and the glow plug must be replaced. If a glow plug is replaced and the tip is missing or burned off, the cylinder head must be removed and all debris must be cleaned out of the cylinder. Test the affected glow plug harness between the glow plug controller and the glow plug for the following conditions: An open A short to ground A short to voltage Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 7
7Test for an intermittent and for a poor connection at the harness connector of the glow plug controller. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 12
8IMPORTANT: The DMM and test leads must be calibrated to 0 ohms in order to prevent misdiagnosis. Use the DMM to perform this test. Refer to the DMM User Manual for calibration procedure. Measure the resistance between the affected glow plug terminal of the glow plug and a good ground on the engine with a DMM.Does the DMM display a resistance below the specified value?1 ohmsGo to Step 9Go to Step 11
9IMPORTANT: The DMM and test leads must be calibrated to 0 ohms in order to prevent misdiagnosis. Use the DMM to perform this test. Refer to the DMM User Manual for calibration procedure. Disconnect the glow plug controller harness connector. Measure the resistance from the affected glow plug supply voltage circuit between the glow plug harness connector and the glow plug controller harness connector with a DMM. Does the DMM display a resistance below the specified value?1 ohmsGo to Step 12Go to Step 10
10Repair or replace the glow plug harness. Refer to Wiring Repairs in Wiring Systems. Is the action complete?Go to Step 13
11IMPORTANT: If a glow plug is replaced and the tip is missing or burned off, the cylinder head must be removed and all debris must be cleaned out of the cylinder. Replace the glow plug. Refer to Glow Plug Replacement - Bank 1 or Glow Plug Replacement - Bank 2 .Did you complete the replacement?Go to Step 13
12Replace the glow plug controller. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 13
13Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 14
14Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK
IMPORTANT
The glow plugs can only be commanded ON once per ignition cycle. Turn the ignition OFF and ON to command the glow plugs ON each time with a scan tool.
IMPORTANT
If a glow plug control circuit is shorted to 12 volts, the glow plug will be damaged and the glow plug must be replaced. If a glow plug is replaced and the tip is missing or burned off, the cylinder head must be removed and all debris must be cleaned out of the cylinder.
IMPORTANT
The DMM and test leads must be calibrated to 0 ohms in order to prevent misdiagnosis. Use the DMM to perform this test. Refer to the DMM User Manual for calibration procedure.
IMPORTANT
The DMM and test leads must be calibrated to 0 ohms in order to prevent misdiagnosis. Use the DMM to perform this test. Refer to the DMM User Manual for calibration procedure.
IMPORTANT
If a glow plug is replaced and the tip is missing or burned off, the cylinder head must be removed and all debris must be cleaned out of the cylinder.

DTC P0671-P0678

The engine control module (ECM) provides 5 volts to the following sensors

  1. The accelerator pedal position (APP) sensor 3
  2. The camshaft position (CMP) sensor

These 5-volt reference circuits are independent of each other outside the ECM, but are bussed together inside the ECM. Therefore, a circuit condition on one sensor 5-volt reference circuit may affect the other sensor 5-volt reference circuits. The ECM monitors the voltage on the 5-volt reference circuit. If the ECM detects a low voltage condition, DTC P0698 sets.

This diagnostic procedure supports the following DTC

DTC P0698 5-Volt Reference 3 Circuit Low Voltage

  1. The ignition is ON.
  2. DTC P0698 runs continuously.
  1. The ECM detects the 5-volt reference 3 circuit voltage is less than 4.7 volts.
  2. The above condition is present 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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the Freeze Frame/Failure records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 3Go to Intermittent Conditions
3Turn OFF the ignition. Disconnect the accelerator pedal position (APP) sensor. Turn ON the ignition, with the engine OFF. Observe the 5-Volt Reference 3 parameter with a scan tool. Is the 5-Volt Reference 3 parameter within the specified range?4.7-5.2 VGo to Step 8Go to Step 4
4Disconnect the camshaft position (CMP) sensor. Turn ON the ignition, with the engine OFF. Observe the 5-Volt Reference 3 parameter with a scan tool. Is the 5-Volt Reference 3 parameter within the specified range?4.7-5.2 VGo to Step 9Go to Step 5
5Test the 5-volt reference circuit of the CMP sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 10Go to Step 6
6Test the 5-volt reference circuit for the APP sensor 3 for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 10Go to Step 7
7Replace the engine control module (ECM). Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 10
8Replace the APP sensor. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Did you complete the replacement?Go to Step 10
9Replace the CMP sensor. Refer to Camshaft Position (CMP) Sensor Replacement . Did you complete the replacement?Go to Step 10
10Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 3Go to Step 11
11Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P0698

The engine control module (ECM) provides 5 volts to the following sensors

  1. The accelerator pedal position (APP) sensor 3
  2. The camshaft position (CMP) sensor

These 5-volt reference circuits are independent of each other outside the ECM, but are bussed together inside the ECM. Therefore, a circuit condition on one sensor 5-volt reference circuit may affect the other sensor 5-volt reference circuits. The ECM monitors the voltage on the 5-volt reference circuit. If the ECM detects a high voltage condition, DTC P0699 sets.

This diagnostic procedure supports the following DTC

DTC P0699 5-Volt Reference 3 Circuit High Voltage

  1. The ignition is ON.
  2. DTC P0699 runs continuously.
  1. The ECM detects the 5-volt reference 3 circuit voltage is more than 5.2 volts.
  2. The above condition is present 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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Turn ON the ignition, with the engine OFF. Observe the 5-Volt Reference 3 parameter with a scan tool. Is the 5-Volt Reference 3 parameter more than the specified value?5.2 VGo to Step 3Go to Intermittent Conditions
3Test the accelerator pedal position (APP) 3 sensor 5-volt reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 6Go to Step 4
4Test the camshaft position (CMP) sensor 5-volt reference for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 6Go to Step 5
5Replace the engine control module (ECM). Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 6
6Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 7
7Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P0699

The malfunction indicator lamp (MIL) request circuit signals the engine control module (ECM) that the transmission control module (TCM) is requesting MIL illumination.

This diagnostic procedure supports the following DTC

DTC P0700 Transmission Control Module (TCM) Requested MIL Illumination

  1. The ignition is ON for more than 7 seconds.
  2. DTC P0802 has ran and passed.
  3. DTC P0700 runs continuously.

The TCM is requesting MIL illumination or the MIL request circuit is shorted to ground.

  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.

Test Description

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

  1. 2: If the TCM has diagnostic trouble codes (DTCs) set that are requesting MIL illumination, those DTCs must be diagnosed first.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Connect a scan tool. Are there any transmission DTCs set?Go to Step 3Go to Step 5
3Diagnose and repair any transmission DTCs. Are there any transmission DTCs?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationGo to Step 4
4Observe the Freeze Frame/Failure Records data for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. 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. Does the DTC fail this ignition?Go to Step 5Go to Intermittent Conditions
5Disconnect the transmission control module (TCM). Refer to Transmission Control Module (TCM) Replacement in Automatic Transmission - Allison. Connect a DMM from the malfunction indicator lamp (MIL) request circuit in the TCM harness connector to a good ground. Turn ON the ignition, with the engine OFF. Does the voltage measure near the specified value?B+Go to Step 7Go to Step 6
6Test the MIL request circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 8
7Test for shorted terminals and for intermittent and poor connections at the TCM. Refer to Testing for Intermittent Conditions and Poor Connections , Repairing Connector Terminals , and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 9
8Test for shorted terminals and for intermittent and poor connections at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections , Repairing Connector Terminals , and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 10
9Replace the TCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 11
10Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 11
11Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 12
12Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P0700

The transmission control module (TCM) malfunction indicator lamp (MIL) request circuit signals the engine control module (ECM) that the TCM is requesting MIL illumination.

This diagnostic procedure supports the following DTC

DTC P0802 Transmission Control Module (TCM) MIL Request Circuit

  1. The ignition is ON.
  2. DTC P0802 runs once an ignition cycle.

The ECM is detecting an improper voltage level on the TCM MIL request circuit within 7 seconds of the key ON.

  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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the Freeze Frame/Failure Records data for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or as close to the Freeze Frame/Failure Records data that you observed. Does the DTC fail this ignition?Go to Step 3Go to Intermittent Conditions
3Turn OFF the ignition. Disconnect the transmission control module (TCM). Refer to Transmission Control Module (TCM) Replacement in Automatic Transmission - Allison. Connect a DMM from the TCM malfunction indicator lamp (MIL) request circuit at the TCM harness connector to a good ground. Turn ON the ignition, with the engine OFF. Does the voltage measure near the specified value?B+Go to Step 4Go to Step 5
4Test the TCM MIL request circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 6
5Test the TCM MIL request circuit for an open and repair. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 6
6Leave the TCM disconnected. Connect a fused jumper wire from the TCM MIL request circuit in the TCM harness connector to a good ground. Clear the DTCs with a scan tool. Does DTC P0700 set, but not DTC P0802?Go to Step 7Go to Step 9
7Perform the following procedures: Check the battery and powers and grounds of the TCM for high resistance or corrosion. Refer to Circuit Testing and Connector Repairs in Wiring Systems. Test the TCM connectors for a poor connection. Refer to Circuit Testing and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 8
8Replace the TCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the action?Go to Step 11
9Test the engine control module (ECM) connectors for a poor connection. Refer to Circuit Testing and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 10
10Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 11
11Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 12
12Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P0802

The engine control module (ECM) uses the fuel rail pressure (FRP) sensor to determine fuel pressure to the fuel injectors. This is then compared to the calculated target fuel pressure as determined by the ECM. The ECM adjusts the FRP by modulating the duty cycle of the control driver of the fuel pressure regulator. Injector pulse duration is determined by the measured rail pressure and the target injection fuel into each cylinder. If a sensor circuit malfunction is detected, or the commanded fuel injection pump flow is not within the proper range for a given engine load and speed, DTCs will be set.

DTC Description

This diagnostic procedure supports the following DTC

DTC P1093 Fuel Rail Pressure Low During Power Enrichment

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

The difference between the commanded fuel pressure and the actual fuel pressure is more than 20 MPa.

OR

The FRP regulator fuel flow is more than 19 200 mm 3 at 800 RPM, or more than 44 400 mm 3 at 2,000 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.

The engine will be in reduced power mode to replace using no more than 2,000 RPM.

  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

  1. This DTC does not set for an idle condition.
  2. The following are some conditions that may cause DTC P0087 and DTC P1093 to set: Excessive fuel return to the tank A fuel injection pump failure A fuel pressure regulator (RPCV) failure
  3. If you have to prime the fuel system, inspect for the following conditions: A restricted fuel supply line A fuel supply line air leak-Refer to «Fuel System Diagnosis»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis) .
  4. A sticking fuel pressure regulator may set this DTC. Refer to «Fuel System Diagnosis - High Pressure Side»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis) . Perform this test under the conditions for which the DTC set.
  5. 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) .
  6. If the condition is still 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. 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. 4: The engine will not start if the fuel leak is large enough.
  3. 5: This step inspects for an inaccurate fuel rail pressure sensor.
  4. 6: This step inspects for fuel leaks into the engine oil.
  5. 7: This step inspects for a restriction in the fuel system between the fuel injection pump and the fuel tank.
  6. 8: This test verifies 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. At higher ambient temperatures, the fuel pressure will be lower, but still more than 145 MPa.
  7. 9: This step inspects 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 verifies 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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Is DTC P0168 or P0090 also set?Go to Diagnostic Trouble Code (DTC) List - VehicleGo to Step 3
3IMPORTANT: Failure to wait until there is no engine control module (ECM) communications with the scan tool will result in misdiagnosis. Turn OFF the ignition for 30 seconds. Turn ON the ignition, with the engine OFF. Observe the FRP Regulator Command parameter with a scan tool. Is the FRP Regulator Command more than the specified value?20%Go to Step 4Go to Step 16
4Attempt to start the engine. Does the engine start and idle?Go to Step 5Go to Engine Cranks but Does Not Run
5Turn ON the ignition, with the engine OFF. Observe the Actual Fuel Rail Pressure parameter with a scan tool. Is the Actual Fuel Rail Pressure Parameter within the specified range?1-1.8 MPaGo to Step 6Go to Step 10
6Inspect for fuel contamination. Refer to Contaminants-in-Fuel Diagnosis . Did you find and correct the condition?Go to Step 17Go to Step 7
7Install the J 44638 Vacuum Gage on the fuel fitting located on the right side front of the engine. Special Tools . Start and run the engine at idle. Observe the vacuum gage while increasing RPM slowly to wide open throttle (WOT) in Park or Neutral. Does the vacuum measure less than the specified value through the entire RPM range?5 inchesGo to Step 8Go to Step 11
8Start and idle the engine until the idle speed drops to 680 RPM. Command the fuel pressure control to 160 MPa with a scan tool. Observe the Actual Fuel Rail Pressure parameter with a scan tool. Is the Actual Fuel Rail Pressure parameter more than the specified value?145 MPaGo to Step 9Go to Fuel System Diagnosis - High Pressure Side
9IMPORTANT: If the fuel temperature is near 121°C (250°F) during the duplication of the complaint or in the Failure Records for this DTC, inspect for a restriction in the fuel cooler air flow or the fuel heater always ON. Refer to Fuel Heater Always On . Ensure that the J 44638 is still installed on the engine. Special Tools . Operate the vehicle within the conditions for which the customer complaint occurs. Does the vacuum measure less than the specified value through the entire operating range?12 inchesGo to Diagnostic AidsGo to Step 11
10Disconnect the fuel rail pressure (FRP) sensor. Refer to Fuel Rail Pressure (FRP) Sensor Replacement . Observe the Actual Fuel Rail Pressure with a scan tool. Does the Actual Fuel Rail Pressure measure more than the specified value?175 MPaGo to Step 15Go to Step 14
11Replace the fuel filter. Refer to Fuel Filter Replacement . Did you complete the replacement?Go to Step 12
12Ensure that the J 44638 is still installed on the engine. Special Tools . Start and run the engine under the conditions for which the high vacuum occurred in the previous test. Does the vacuum measure less than or equal to the specified value?5 inches at idle 12 inches at high speedGo to Step 17Go to Step 13
13Repair the restriction in the fuel supply lines between the fuel tank and the fuel injection pump. Refer to Fuel System Diagnosis . Did you complete the repair?Go to Step 17
14Inspect the fuel rail pressure sensor signal circuit for a short to ground. Repair as necessary. Refer to Wiring Repairs . Did you find and correct the condition?Go to Step 17Go to Step 16
15Replace the fuel rail pressure sensor. Refer to Fuel Rail Pressure (FRP) Sensor Replacement . Did you complete the replacement?Go to Step 17
16Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 17
17Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 18
18Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - VehicleSystem OK
IMPORTANT
Failure to wait until there is no engine control module (ECM) communications with the scan tool will result in misdiagnosis.
IMPORTANT
If the fuel temperature is near 121°C (250°F) during the duplication of the complaint or in the Failure Records for this DTC, inspect for a restriction in the fuel cooler air flow or the fuel heater always ON. Refer to Fuel Heater Always On .

DTC P1093

The engine control module (ECM) uses the fuel rail pressure (FRP) sensor to determine fuel pressure to the fuel injectors. This is then compared to the calculated target fuel pressure as determined by the ECM. The ECM adjusts the FRP by modulating the duty cycle of the control driver of the fuel pressure regulator. Injector pulse duration is determined by the measured rail pressure and the target injection fuel into each cylinder. If a sensor circuit malfunction is detected, or the commanded fuel injection pump flow is not within the proper range for a given engine load and speed, DTC will be set.

This diagnostic procedure supports the following DTC

DTC P1094 Fuel Rail Pressure Low During Idle or Decel Fuel Cut-Off (DFCO)

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

The difference between the FRP sensor and the commanded fuel injection pump flow is more than 30 MPa.

  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.
  1. If you have to prime the fuel system, inspect for the following conditions: A restricted fuel supply line A fuel supply line air leak-Refer to «Fuel System Diagnosis»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis) .
  2. If the condition is still intermittent, refer to «Intermittent Conditions»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis__intermittent-conditions) .
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Is DTC P1093 also set?Go to DTC P1093Go to Step 3
3Inspect for fuel contamination. Refer to Contaminants-in-Fuel Diagnosis . Did you find and correct the condition?Go to Step 10Go to Step 4
4Attempt to start the engine. Does the engine start and continue to run?Go to Step 5Go to Engine Cranks but Does Not Run
5Is the customer concern also a surging idle?Go to Fuel Pressure Regulator DiagnosisGo to Step 6
6Start and idle the engine. Observe the fuel rail pressure (FRP) regulator fuel flow with a scan tool. Does the FRP regulator fuel flow measure more than the specified value?12 000 mm 3Go to Step 7Go to Diagnostic Aids
7Test the fuel pressure regulator solenoid control circuit between the engine control module (ECM) and the fuel pressure regulator for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 10Go to Step 8
8Test for an intermittent or poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 10Go to Step 9
9Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 10
10Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 11
11Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - VehicleSystem OK

DTC P1094

The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. The sensor is made up of 3 individual sensors within one housing. Three separate signal, low reference, and 5-volt reference circuits are used in order to interface the APP sensor with the engine control module (ECM). Each sensor has a unique functionality to determine pedal position as shown in the table below. The ECM uses the APP sensor to determine the amount of acceleration or deceleration desired by the person driving the vehicle via fuel injector control. If the ECM detects a condition with more than one sensor within the APP sensor, DTC P1125 sets.

APP SensorActual Pedal Position% Depressed as Observed on a Scan ToolVoltage as Observed on a Scan Tool
1Pedal at rest0.52 - .80
1Pedal at full travel1002.12 - 2.78
2Pedal at rest04.25 - 4.53
2Pedal at full travel1002.24 - 2.93
3Pedal at rest03.95 - 4.13
3Pedal at full travel1002.69 - 3.16

APP Sensor Position Table

This diagnostic procedure supports the following DTC

DTC P1125 Accelerator Pedal Position (APP) System

  1. The ignition switch is in the crank or run position.
  2. The ignition voltage is between 7-16 volts.
  3. DTC P1125 runs continuously.
  1. The ECM detects a condition with more than one APP sensor.
  2. All of the above conditions present for less than 1 second.
  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. If one or more APP sensor DTCs are set for a single APP sensor, the following occurs: The control module will not command Reduced Engine Power mode. The control module will use the remaining two APP sensors to calculate throttle response.
  5. If certain multiple APP sensor DTCs are set for more than one APP sensor, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to a predetermined value to limit the amount of throttle control. The message center displays Reduced Engine Power.
  6. If all three APP sensors are out of range, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to 0 percent. The control module only allows the engine to idle. The message center displays Reduced Engine Power.
  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.
  1. The APP sensor 2 5-volt reference circuit is shared with the barometric pressure (BARO) sensor and the turbo boost solenoid and they are internally connected within the ECM.
  2. For an intermittent, refer to «Intermittent Conditions»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis__intermittent-conditions) .
StepActionYesNo
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Is DTC P0642, P0643, P0652, P0653, P0698, or P0699 also set?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationGo to Step 3
3This DTC indicates that 2 or more accelerator pedal position (APP) sensor DTCs are set. Are other APP sensor DTCs set?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

DTC P1125

The engine control module (ECM) enables the appropriate fuel injector on the compression stroke for each cylinder. The ECM controls the fuel injection control module (FICM) by grounding the control circuit via a solid state device called a driver. The ECM monitors the state of the driver. If the ECM detects an incorrect voltage for the commanded state of an injector driver, DTCs P1223, P1226, P1229, P1232, P1235, P1238, P1241, or P1244 will set.

This diagnostic procedure supports the following DTCs

  1. DTC P1223 Injector 1 Output Circuit
  2. DTC P1226 Injector 2 Output Circuit
  3. DTC P1229 Injector 3 Output Circuit
  4. DTC P1232 Injector 4 Output Circuit
  5. DTC P1235 Injector 5 Output Circuit
  6. DTC P1238 Injector 6 Output Circuit
  7. DTC P1241 Injector 7 Output Circuit
  8. DTC P1244 Injector 8 Output Circuit
  1. The engine is running.
  2. The ignition voltage is between 6-18 volts.
  1. The ECM detects that the commanded state and the actual state of the control circuit does not match.
  2. The condition exists for less than 1 second.
  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. Clear the MIL and the DTC with a scan tool.

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

  1. 4: This step determines if there are 4 fuel injector control circuit DTCs set in a group. A short to voltage will set 4 fuel injector control circuit DTCs for cylinders 1, 4, 6, 7, or cylinders 2, 3, 5, 8. Refer to DTC Descriptors in order to determine which cylinders are affected. If there are more than 4 fuel injector control circuit DTCs set, a short to voltage on a fuel injector control circuit is likely the cause of the concern. A short to voltage will set more than 4 fuel injector control circuit DTCs.
  2. 5: This step determines if there are 4 fuel injector control circuit DTCs set in a group. A short to voltage will set 4 fuel injector control circuit DTCs for cylinders 2, 3, 5, 8. If there is only 1 fuel injector DTC set, an open circuit, poor connector, or short to ground is likely the cause of the concern. Refer to DTC Descriptors in order to determine which cylinder is causing the condition.
  3. 6: This step verifies that the ECM is supplying the appropriate frequency, Hz, through the fuel injector control circuits to the FICM. If the DMM displays 2-4 Hz while cranking, inspect for a poor connection at the FICM.
  4. 8: This step is testing for a short to ground on a fuel injector control circuit. If the test lamp illuminates on any fuel injector control circuit, a short to ground is the cause of the condition.
  5. 9: This step is testing for a short to a voltage. If the DMM displays a voltage greater than the specified value, a short to voltage is the cause of the condition.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Start and idle the engine. Monitor the DTC Failed This Ignition parameter with a scan tool. Do any of the DTCs P1223-1244 fail this ignition?Go to Step 4Go to Step 3
3Observe the Freeze Frame/Failure Records for this DTC with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Does the DTC fail this ignition?Go to Step 4Go to Intermittent Conditions
4Are DTC P1223, P1232, P1238, and P1241 all set?Go to Step 9Go to Step 5
5Are DTC P1226, P1229, P1235, and P1244 all set?Go to Step 9Go to Step 6
6Turn OFF the ignition. Disconnect the harness connector C1 of the fuel injection control module (FICM). IMPORTANT: Use the J 35616-94 Connector Adapter of the J 35616 to probe the FICM connector. While cranking the engine, measure the frequency of the appropriate fuel injector control circuit with a DMM. Refer to Measuring Frequency in Wiring Systems. Is the voltage frequency more than the specified value?2.9 HzGo to Step 12Go to Step 7
7Turn OFF the ignition. Disconnect harness connector C2 of the engine control module (ECM). Test the appropriate fuel injector control circuit for an open or short to another affected fuel injector control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 8
8Turn OFF the ignition. Verify the harness connector C2 of the ECM is still disconnected. Probe the affected fuel injector control circuits with a test lamp connected to battery voltage. Refer to DTC Descriptors and Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate on any of the fuel injector control circuits?Go to Step 10Go to Step 15
9Turn OFF the ignition. Disconnect the harness connector C2 of the ECM. Turn ON the ignition, with the engine OFF. Measure the voltage from each of the fuel injector control circuits with a DMM. Refer to Probing Electrical Connectors in Wiring Systems. Is the voltage more than the specified value on any of the fuel injector control circuits?1 VGo to Step 11Go to Step 15
10Test the appropriate fuel injector control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 13
11Test the appropriate fuel injector control circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 14
12Inspect for poor connections at the harness connector of the FICM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 14
13Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 15
14Replace the FICM. Refer to Fuel Injection Control Module Replacement . Did you complete the replacement?Go to Step 16
15Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 16
16Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 17
17Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK
IMPORTANT
Use the J 35616-94 Connector Adapter of the J 35616 to probe the FICM connector.

DTC P1223, P1226, P1229, P1232, P1235, P1238, P1241, or P1244

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. If the ECM detects a difference between the learned closed position and the commanded closed position for a calibrated amount of time, DTC P1404 sets.

This diagnostic procedure supports the following DTC

DTC P1404 Exhaust Gas Recirculation (EGR) Closed Position Performance

  1. DTCs P0642 and P0643 are not set.
  2. The ignition is ON for more than 0.5 seconds.
  3. The ignition voltage is between 11-18 volts.
  4. The intake air temperature (IAT) is between 0-150.75°C (32-303.35°F).
  5. The engine coolant temperature (ECT) is between 57-99.75°C (134.6-211.6°F).
  6. The barometric pressure (BARO) is more than 72 kPa.
  7. The power take off (PTO) is not engaged.
  8. The EGR has been commanded to more than 35 percent.
  9. The current desired EGR position is 0 percent.
  10. DTC P1404 runs continuously once the above conditions are met.
  1. The actual EGR position is 0.8 volts, 6 percent, more than the learned closed position when the EGR valve is commanded closed, or the EGR learned minimum position is more than 1.25 volts.
  2. The above condition is present for more than 5 seconds.

Action Taken When the DTC Sets - California

  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.

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 Failure Records.
  4. The driver information center (DIC), 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. Clear the MIL and the DTC with a scan tool.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views and Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2IMPORTANT: Attaching the shop exhaust system to the vehicle may cause false exhaust gas recirculation (EGR) DTCs to set. Turn ON the ignition. Observe the EGR Position parameter with a scan tool. Does the EGR Position parameter read more than the specified value?1.25 VGo to Step 4Go to Step 3
3Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition cycle?Go to Step 4Go to Intermittent Conditions
4Is DTC P0403, P0405, or P0406 also set?Go to DTC P0403 or DTC P0405 or DTC P0406Go to Step 5
5Test for shorted terminals and poor connections at the exhaust gas recirculation (EGR) valve. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 12Go to Step 6
6Disconnect the EGR valve. Turn ON the ignition. Set up the DMM to measure amperage. Connect a test lamp and a DMM in series between the 5-volt reference circuit of the EGR position sensor and the low reference circuit of the EGR position sensor. Measure the amperage and note as Current Draw. Remove the DMM and connect the test lamp between the 5-volt reference circuit of the EGR position sensor and the low reference circuit of the EGR position sensor. Connect a DMM in parallel between the low reference circuit of the EGR position sensor and a good ground. Measure the voltage and note as Low Reference Voltage Drop. Divide the Low Reference Voltage Drop by the Current Draw in order to calculate the resistance in the low reference circuit. Is the calculated resistance more than the specified value?5 ohmsGo to Step 7Go to Step 9
7Test for shorted terminals and poor connections at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 12Go to Step 8
8Disconnect the ECM. Repair the high resistance in the low reference circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 12Go to Step 11
9Remove the EGR valve. Refer to Exhaust Gas Recirculation (EGR) Valve Replacement . Inspect for debris and damage that will cause the EGR valve to stick and clean, if necessary. Refer to Exhaust Gas Recirculation (EGR) System Cleaning . Did you find and correct the condition?Go to Step 12Go to Step 10
10Replace the EGR valve. Refer to Exhaust Gas Recirculation (EGR) Valve Replacement . Did you complete the replacement?Go to Step 12
11Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?Go to Step 12
12Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 13
13Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - VehicleSystem OK
IMPORTANT
Attaching the shop exhaust system to the vehicle may cause false exhaust gas recirculation (EGR) DTCs to set.

DTC P1404

The fuel injector control module (FICM) activates the fuel injector. The engine control module (ECM) signals the FICM to turn ON the injectors through the fuel injector control circuits. The FICM self monitors the supply voltage whenever the ignition is ON.

This diagnostic procedure supports the following DTC

DTC P1550 Fuel Injector Control Module System Voltage

  1. Engine speed is greater than 60 RPM.
  2. Battery voltage is between 11-16 volts.
  3. DTC U0073 or U0105 are not set.
  4. DTC P1550 runs continuously.

The FICM detects low supply voltage for less than 1 second.

  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. 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.
StepActionYesNo
Schematic Reference: Engine Controls Schematics
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Do any other DTCs set?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationGo to Step 3
3IMPORTANT: Use connection pin adapters from J 35616 Adapter Kit. Turn OFF the ignition. Disconnect the fuel injection control module (FICM) connectors. Turn ON the ignition. Probe the FICM power circuits with a DMM connected to one of the FICM ground circuits. Does the voltage measure more than 10 volts?Go to Step 5Go to Step 4
4Repair high resistance in the FICM power or ground circuits. Did you complete the repair?Go to Step 6
5Replace the FICM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 6
6Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 7
7Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK
IMPORTANT
Use connection pin adapters from J 35616 Adapter Kit.

DTC P1550

The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. The sensor is made up of 3 individual sensors within 1 housing. Three separate signal, low reference, and 5-volt reference circuits are used in order to interface the APP sensor with the engine control module (ECM). Each sensor has a unique functionality to determine the pedal position as shown in the table below. The ECM uses the APP sensor to determine the amount of acceleration or deceleration desired by the person driving the vehicle via the fuel injector control. If the ECM determines low voltage with the APP sensor 1 circuit, DTC P2122 sets.

APP SensorActual Pedal Position% Depressed as Observed on a Scan ToolVoltage as Observed on a Scan Tool
1Pedal at rest0.52 - .80
1Pedal at full travel1002.12 - 2.78
2Pedal at rest04.25 - 4.53
2Pedal at full travel1002.24 - 2.93
3Pedal at rest03.95 - 4.13
3Pedal at full travel1002.69 - 3.16

APP Sensor Position Table

This diagnostic procedure supports the following DTC

DTC P2122 Accelerator Pedal Position (APP) Sensor 1 Circuit Low Voltage

  1. DTCs P0642 or P0643 are not set.
  2. The ignition switch is in the Crank or Run position.
  3. The ignition voltage is between 7-16 volts.
  4. DTC P2122 runs continuously.
  1. The APP sensor 1 voltage is less than 0.25 volts.
  2. The above condition is present for less than 1 second.
  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. If one or more APP sensor DTCs are set for a single APP sensor, the following occurs: The control module will not command Reduced Engine Power mode. The control module will use the remaining two APP sensors to calculate throttle response.
  5. If certain multiple APP sensor DTCs are set for more than one APP sensor, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to a predetermined value to limit the amount of throttle control. The message center displays Reduced Engine Power.
  6. If all three APP sensors are out of range, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to 0 percent. The control module only allows the engine to idle. The message center displays Reduced Engine Power.
  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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. 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. Does the DTC fail this ignition?Go to Step 4Go to Step 3
3Select the DTC option using the scan tool. Lightly touch and move the related accelerator pedal position (APP) wiring harnesses and connectors while monitoring the DTC information. Did this DTC fail this ignition during the above test?Go to Step 10Go to Intermittent Conditions
4Disconnect the APP sensor harness connector. Turn ON the ignition, with the engine OFF. Test for voltage at the APP sensor 1 5-volt reference circuit with a DMM. Does the DMM indicate voltage more than the specified value?5 VGo to Step 5Go to Step 6
5Connect a fused jumper between the APP sensor 1 5-volt reference circuit and the APP sensor 1 signal circuit. Observe the APP sensor 1 voltage parameter with a scan tool. Does the scan tool indicate APP sensor 1 voltage at the specified value?5 VGo to Step 11Go to Step 8
6Disconnect the engine control module (ECM) harness connector containing the APP sensor 1 5-volt reference circuit. Test the APP sensor 1 5-volt reference circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 7
7Test the APP sensor 1 5-volt reference circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 12
8Disconnect the ECM harness connector containing the APP sensor 1 signal circuit. Test the APP sensor 1 signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 9
9Test the APP sensor 1 signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 12
10Repair the intermittent condition as necessary. Refer to Connector Repairs and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 15
11Inspect for poor connections at the harness connector of the APP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 13
12Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 14
13Replace the APP sensor assembly. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Did you complete the replacement?Go to Step 15
14Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming. Did you complete the replacement?Go to Step 15
15Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 16
16Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P2122

The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. The sensor is made up of 3 individual sensors within 1 housing. Three separate signal, low reference, and 5-volt reference circuits are used in order to interface the APP sensor with the engine control module (ECM). Each sensor has a unique functionality to determine the pedal position as shown in the table below. The ECM uses the APP sensor to determine the amount of acceleration or deceleration desired by the person driving the vehicle via the fuel injector control. If the ECM determines high voltage in the APP sensor 1 circuit, DTC P2123 sets.

APP SensorActual Pedal Position% Depressed as Observed on a Scan ToolVoltage as Observed on a Scan Tool
1Pedal at rest0.52 - .80
1Pedal at full travel1002.12 - 2.78
2Pedal at rest04.25 - 4.53
2Pedal at full travel1002.24 - 2.93
3Pedal at rest03.95 - 4.13
3Pedal at full travel1002.69 - 3.16

APP Sensor Position Table

This diagnostic procedure supports the following DTC

DTC P2123 Accelerator Pedal Position (APP) Sensor 1 Circuit High Voltage

  1. DTCs P0642 or P0643 are not set.
  2. The ignition switch is in the Crank or Run position.
  3. The ignition voltage is between 7-16 volts.
  4. DTC P2123 runs continuously.
  1. The APP sensor 1 voltage is more than 4.75 volts.
  2. The above condition is present for less than 1 second.
  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. If one or more APP sensor DTCs are set for a single APP sensor, the following occurs: The control module will not command Reduced Engine Power mode. The control module will use the remaining two APP sensors to calculate throttle response.
  5. If certain multiple APP sensor DTCs are set for more than one APP sensor, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to a predetermined value to limit the amount of throttle control. The message center displays Reduced Engine Power.
  6. If all three APP sensors are out of range, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to 0 percent. The control module only allows the engine to idle. The message center displays Reduced Engine Power.
  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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. 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. Does the DTC fail this ignition?Go to Step 4Go to Step 3
3Select the DTC option on the scan tool. Lightly touch and move the related accelerator pedal position (APP) sensor wiring harnesses and connectors while monitoring the DTC information. Did this DTC fail this ignition during the above test?Go to Step 9Go to Intermittent Conditions
4Disconnect the APP sensor harness connector. Turn ON the ignition, with the engine OFF. Observe the APP sensor 1 voltage parameter with a scan tool. Does the scan tool indicate the APP sensor 1 voltage at the specified value?0 VGo to Step 5Go to Step 6
5Connect a fused jumper between the APP sensor 2 signal circuit and the APP sensor 1 low reference circuit. Observe the APP sensor 2 voltage parameter with a scan tool. Does the scan tool indicate APP sensor 2 voltage at the specified value?0 VGo to Step 10Go to Step 8
6Turn OFF the ignition. Disconnect the engine control module (ECM) harness connector containing the APP sensor 1 signal circuit. Turn ON the ignition. Test the APP sensor 1 signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 7
7Turn OFF the ignition. Disconnect the other ECM harness connector. Test the APP sensor 1 signal circuit for a short to all other APP circuits at the APP sensor harness connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 11
8Disconnect the ECM harness connector containing the APP sensor 1 low reference circuit. Test the APP sensor 1 low reference circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 11
9Repair the intermittent condition as necessary. Refer to Connector Repairs and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 14
10Inspect for poor connections at the harness connector of the APP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 12
11Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 13
12Replace the APP sensor assembly. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Did you complete the replacement?Go to Step 14
13Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 14
14Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 15
15Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P2123

The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. The sensor is made up of 3 individual sensors within 1 housing. Three separate signal, low reference, and 5-volt reference circuits are used in order to interface the APP sensor with the engine control module (ECM). Each sensor has a unique functionality to determine the pedal position as shown in the table below. The ECM uses the APP sensor to determine the amount of acceleration or deceleration desired by the person driving the vehicle via the fuel injector control. If the ECM determines high voltage with the APP sensor 2 circuit, DTC P2127 sets.

APP SensorActual Pedal Position% Depressed as Observed on a Scan ToolVoltage as Observed on a Scan Tool
1Pedal at rest0.52 - .80
1Pedal at full travel1002.12 - 2.78
2Pedal at rest04.25 - 4.53
2Pedal at full travel1002.24 - 2.93
3Pedal at rest03.95 - 4.13
3Pedal at full travel1002.69 - 3.16

APP Sensor Position Table

This diagnostic procedure supports the following DTC

DTC P2127 Accelerator Pedal Position (APP) Sensor 2 Circuit Low Voltage

  1. DTCs P0652 or P0653 are not set.
  2. The ignition switch is in the Crank or Run position.
  3. The ignition voltage is between 7-16 volts.
  4. DTC P2127 runs continuously.
  1. The APP sensor 2 voltage is less than 0.25 volts.
  2. The above condition is present for less than 1 second.
  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. If one or more APP sensor DTCs are set for a single APP sensor, the following occurs: The control module will not command Reduced Engine Power mode. The control module will use the remaining two APP sensors to calculate throttle response.
  5. If certain multiple APP sensor DTCs are set for more than one APP sensor, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to a predetermined value to limit the amount of throttle control. The message center displays Reduced Engine Power.
  6. If all three APP sensors are out of range, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to 0 percent. The control module only allows the engine to idle. The message center displays Reduced Engine Power.
  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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. 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. Does the DTC fail this ignition?Go to Step 4Go to Step 3
3Select the DTC option on the scan tool. Lightly touch and move the related accelerator pedal position (APP) sensor wiring harnesses and connectors while monitoring the DTC information. Did this DTC fail this ignition during the above test?Go to Step 8Go to Intermittent Conditions
4Disconnect the APP sensor harness connector. Turn ON the ignition with the engine OFF. Test for voltage at the APP sensor 2 5-volt reference circuit with a DMM. Does the DMM indicate voltage within the specified range?4.8-5.2 VGo to Step 5Go to Step 6
5Test for voltage at the APP sensor 2 signal circuit with a DMM. Does the DMM indicate voltage at the specified value?5.05 VGo to Step 9Go to Step 7
6Disconnect the engine control module (ECM) harness connector containing the APP sensor 2 5-volt reference circuit. Test the APP sensor 2 5-volt reference circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 10
7Disconnect the ECM harness connector containing the APP sensor 2 signal circuit. Test the APP sensor 2 signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 10
8Repair the intermittent condition, as necessary. Refer to Connector Repairs and Repairing Connector Terminals in Wiring Systems. Did you complete the repair?Go to Step 13
9Inspect for poor connections at the harness connector of the APP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 11
10Inspect for poor connections at the harness connector of the APP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 12
11Replace the APP sensor assembly. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Did you complete the replacement?Go to Step 13
12Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 13
13Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 14
14Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P2127

The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. The sensor is made up of 3 individual sensors within 1 housing. Three separate signal, low reference, and 5-volt reference circuits are used in order to interface the APP sensor with the engine control module (ECM). Each sensor has a unique functionality to determine the pedal position as shown in the table below. The ECM uses the APP sensor to determine the amount of acceleration or deceleration desired by the person driving the vehicle via the fuel injector control. If the ECM determines high voltage with the APP sensor 2 circuit, DTC P2128 sets.

APP SensorActual Pedal Position% Depressed as Observed on a Scan ToolVoltage as Observed on a Scan Tool
1Pedal at rest0.52 - .80
1Pedal at full travel1002.12 - 2.78
2Pedal at rest04.25 - 4.53
2Pedal at full travel1002.24 - 2.93
3Pedal at rest03.95 - 4.13
3Pedal at full travel1002.69 - 3.16

APP Sensor Position Table

This diagnostic procedure supports the following DTC

DTC P2128 Accelerator Pedal Position (APP) Sensor 2 Circuit High Voltage

  1. DTCs P0652 or P0653 are not set.
  2. The ignition switch is in the Crank or Run position.
  3. The ignition voltage is between 7-16 volts.
  4. DTC P2128 runs continuously.
  1. The APP sensor 2 voltage is more than 4.75 volts.
  2. The above condition is present for less than 1 second.
  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. If one or more APP sensor DTCs are set for a single APP sensor, the following occurs: The control module will not command Reduced Engine Power mode. The control module will use the remaining two APP sensors to calculate throttle response.
  5. If certain multiple APP sensor DTCs are set for more than one APP sensor, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to a predetermined value to limit the amount of throttle control. The message center displays Reduced Engine Power.
  6. If all three APP sensors are out of range, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to 0 percent. The control module only allows the engine to idle. The message center displays Reduced Engine Power.
  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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. 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. Does the DTC fail this ignition?Go to Step 4Go to Step 3
3Select the DTC option on the scan tool. Lightly touch and move the related accelerator pedal position (APP) sensor wiring harnesses and connectors while monitoring the DTC information. Did this DTC fail this ignition during the above test?Go to Step 10Go to Intermittent Conditions
4Disconnect the APP sensor harness connector. Turn ON the ignition, with the engine OFF. Measure voltage at the APP sensor 2 signal circuit with a DMM. Does the DMM indicate voltage within the specified range?4.8-5.2 VGo to Step 5Go to Step 7
5Probe the signal circuit of the APP sensor 2 with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 8Go to Step 6
6Connect a fused jumper between the APP sensor 3 signal circuit and the APP sensor 2 low reference circuit. Observe the APP sensor 3 voltage parameter with a scan tool. Does the scan tool indicate APP sensor 3 voltage at the specified value?0 VGo to Step 12Go to Step 10
7Turn OFF the ignition. Disconnect the engine control module (ECM) harness connector containing the APP sensor 2 signal circuit. Test the APP sensor 2 signal circuit for an open or for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 8
8Turn ON the ignition. Test the APP sensor 2 signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 9
9Turn OFF the ignition. Disconnect the ECM harness connectors. Test the APP sensor 2, signal circuit for a short to all other APP circuits at the APP sensor harness connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 13
10Disconnect the ECM harness connector containing the APP sensor 2 low reference circuit. Test the APP sensor 2 low reference circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 13
11Repair the intermittent condition as necessary. Refer to Connector Repairs and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 16
12Inspect for poor connections at the harness connector of the APP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 14
13Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 15
14Replace the APP sensor assembly. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Did you complete the replacement?Go to Step 16
15Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 16
16Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 17
17Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P2128

The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. The sensor is made up of 3 individual sensors within 1 housing. Three separate signal, low reference, and 5-volt reference circuits are used in order to interface the APP sensor with the engine control module (ECM). Each sensor has a unique functionality to determine the pedal position as shown in the table below. The ECM uses the APP sensor to determine the amount of acceleration or deceleration desired by the person driving the vehicle via the fuel injector control. If the ECM determines low voltage with the APP sensor 3 circuit, DTC P2132 sets.

APP SensorActual Pedal Position% Depressed as Observed on a Scan ToolVoltage as Observed on a Scan Tool
1Pedal at rest0.52 - .80
1Pedal at full travel1002.12 - 2.78
2Pedal at rest04.25 - 4.53
2Pedal at full travel1002.24 - 2.93
3Pedal at rest03.95 - 4.13
3Pedal at full travel1002.69 - 3.16

APP Sensor Position Table

This diagnostic procedure supports the following DTC

DTC P2132 Accelerator Pedal Position (APP) Sensor 3 Circuit Low Voltage

  1. DTCs P0698 or P0699 are not set.
  2. The ignition switch is in the Crank or Run position.
  3. The ignition voltage is between 7-16 volts.
  4. DTC P2132 runs continuously.
  1. The APP sensor 3 voltage is less than 1.49 volts.
  2. The above condition is present for less than 1 second.
  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. If one or more APP sensor DTCs are set for a single APP sensor, the following occurs: The control module will not command Reduced Engine Power mode. The control module will use the remaining two APP sensors to calculate throttle response.
  5. If certain multiple APP sensor DTCs are set for more than one APP sensor, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to a predetermined value to limit the amount of throttle control. The message center displays Reduced Engine Power.
  6. If all three APP sensors are out of range, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to 0 percent. The control module only allows the engine to idle. The message center displays Reduced Engine Power.
  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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. 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. Does the DTC fail this ignition?Go to Step 4Go to Step 3
3Select the DTC option using the scan tool. Lightly touch and move the related accelerator pedal position (APP) wiring harnesses and connectors while monitoring the DTC information. Did this DTC fail this ignition during the above test?Go to Step 8Go to Intermittent Conditions
4Disconnect the APP sensor harness connector. Turn ON the ignition, with the engine OFF. Test for voltage at the APP sensor 3 5-volt reference circuit with a DMM. Does the DMM indicate voltage more than the specified value?5 VGo to Step 5Go to Step 6
5Test for voltage at the APP sensor 3 signal circuit with a DMM. Does the DMM indicate voltage at the specified value?5.05 VGo to Step 9Go to Step 7
6Disconnect the engine control module (ECM) harness connector containing the APP sensor 3 5-volt reference circuit. Test the APP sensor 3 5-volt reference circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 10
7Disconnect the ECM harness connector containing the APP sensor 3 signal circuit. Test the APP sensor 3 signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 10
8Repair the intermittent condition as necessary. Refer to Connector Repairs and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 13
9Inspect for poor connections at the harness connector of the APP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 11
10Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 12
11Replace the APP sensor assembly. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Did you complete the replacement?Go to Step 13
12Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 13
13Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 14
14Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P2132

The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. The sensor is made up of 3 individual sensors within 1 housing. Three separate signal, low reference, and 5-volt reference circuits are used in order to interface the APP sensor with the engine control module (ECM). Each sensor has a unique functionality to determine the pedal position as shown in the table below. The ECM uses the APP sensor to determine the amount of acceleration or deceleration desired by the person driving the vehicle via the fuel injector control. If the ECM determines high voltage with the APP sensor 3 circuit, DTC P2138 sets.

APP SensorActual Pedal Position% Depressed as Observed on a Scan ToolVoltage as Observed on a Scan Tool
1Pedal at rest0.52 - .80
1Pedal at full travel1002.12 - 2.78
2Pedal at rest04.25 - 4.53
2Pedal at full travel1002.24 - 2.93
3Pedal at rest03.95 - 4.13
3Pedal at full travel1002.69 - 3.16

APP Sensor Position Table

This diagnostic procedure supports the following DTC

DTC P2133 Accelerator Pedal Position (APP) Sensor 3 Circuit High Voltage

  1. DTCs P0698 or P0699 are not set.
  2. The ignition switch is in the Crank or Run position.
  3. The ignition voltage is between 7-16 volts.
  4. DTC P2133 runs continuously.
  1. The APP sensor 3 voltage is more than 4.75 volts.
  2. The above condition is present for less than 1 second.
  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. If one or more APP sensor DTCs are set for a single APP sensor, the following occurs: The control module will not command Reduced Engine Power mode. The control module will use the remaining two APP sensors to calculate throttle response.
  5. If certain multiple APP sensor DTCs are set for more than one APP sensor, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to a predetermined value to limit the amount of throttle control. The message center displays Reduced Engine Power.
  6. If all three APP sensors are out of range, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to 0 percent. The control module only allows the engine to idle. The message center displays Reduced Engine Power.
  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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. 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. Does the DTC fail this ignition?Go to Step 4Go to Step 3
3Select the DTC option on the scan tool. Lightly touch and move the related accelerator pedal position (APP) sensor wiring harnesses and connectors while monitoring the DTC information. Did this DTC fail this ignition during the above test?Go to Step 10Go to Intermittent Conditions
4Disconnect the APP sensor harness connector. Turn ON the ignition, with the engine OFF. Measure voltage at the APP sensor 3 signal circuit with a DMM. Does the DMM indicate voltage within the specified range?4.8-5.2 VGo to Step 5Go to Step 7
5Probe the signal circuit of the APP sensor 3 with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate?Go to Step 8Go to Step 6
6Connect a fused jumper between the APP sensor 2 signal circuit and the APP sensor 3 low reference circuit. Observe the APP sensor 2 voltage parameter with a scan tool. Does the scan tool indicate APP sensor 2 voltage at the specified value?0 VGo to Step 12Go to Step 10
7Turn OFF the ignition. Disconnect the engine control module (ECM) harness connector containing the APP sensor 3 signal circuit. Test the APP sensor 3 signal circuit for an open or for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 8
8Turn ON the ignition. Test the APP sensor 3 signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 9
9Turn OFF the ignition. Disconnect the ECM harness connectors. Test the APP sensor 3 signal circuit for a short to all other APP circuits at the APP sensor harness connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 13
10Disconnect the ECM harness connector containing the APP sensor 3 low reference circuit. Test the APP sensor 3 low reference circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 13
11Repair the intermittent condition as necessary. Refer to Connector Repairs and Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 16
12Inspect for poor connections at the harness connector of the APP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 14
13Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 16Go to Step 15
14Replace the APP sensor assembly. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Did you complete the replacement?Go to Step 16
15Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 16
16Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 17
17Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P2133

The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. The sensor is made up of 3 individual sensors within 1 housing. Three separate signal, low reference, and 5-volt reference circuits are used in order to interface the APP sensor with the engine control module (ECM). Each sensor has a unique functionality to determine the pedal position as shown in the table below. The ECM uses the APP sensor to determine the amount of acceleration or deceleration desired by the person driving the vehicle via the fuel injector control. If the ECM determines an out of range condition between APP sensor 1 and APP sensor 2, DTC P2138 sets.

APP SensorActual Pedal Position% Depressed as Observed on a Scan ToolVoltage as Observed on a Scan Tool
1Pedal at rest0.52 - .80
1Pedal at full travel1002.12 - 2.78
2Pedal at rest04.25 - 4.53
2Pedal at full travel1002.24 - 2.93
3Pedal at rest03.95 - 4.13
3Pedal at full travel1002.69 - 3.16

APP Sensor Position Table

This diagnostic procedure supports the following DTC

DTC P2138 Accelerator Pedal Position (APP) Sensor 1-2 Correlation

  1. DTCs P0642, P0643, P0652, P0653, P2122, P2123, P2132, P2133 are not set.
  2. The ignition switch is in the Crank or Run position.
  3. The ignition voltage is between 7-16 volts.
  4. DTC P2138 runs continuously once the above conditions are met.
  1. The APP sensor 1 and the APP sensor 2 are more than 10 percent out of range of each other.
  2. The above condition is present for less than 1 second.
  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. If one or more APP sensor DTCs are set for a single APP sensor, the following occurs: The control module will not command Reduced Engine Power mode. The control module will use the remaining two APP sensors to calculate throttle response.
  5. If certain multiple APP sensor DTCs are set for more than one APP sensor, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to a predetermined value to limit the amount of throttle control. The message center displays Reduced Engine Power.
  6. If all three APP sensors are out of range, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to 0 percent. The control module only allows the engine to idle. The message center displays Reduced Engine Power.
  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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. 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. Does the DTC fail this ignition?Go to Step 4Go to Step 3
3Select the DTC option using the scan tool. Lightly touch and move the related accelerator pedal position (APP) wiring harnesses and connectors while monitoring the DTC information. Did this DTC fail this ignition during the above test ?Go to Step 4Go to Intermittent Conditions
4Turn OFF the ignition. Disconnect the APP sensor harness connector. Turn ON the ignition. Test for voltage at the APP sensor 2 5-volt reference circuit with a test lamp connected to ground. Does the test lamp illuminate?Go to Step 5Go to Step 14
5Connect a test lamp between the APP sensor 2 5-volt reference circuit and the APP sensor 2 low reference circuit. Does the test lamp illuminate?Go to Step 6Go to Step 15
6Disconnect the test lamp. With the APP sensor harness connector still disconnected, observe the APP sensor 1 voltage parameter with a scan tool. Is the APP sensor 1 voltage less than the specified value?1 VGo to Step 13Go to Step 7
7Is the APP sensor 2 voltage more than the specified value?4 VGo to Step 8Go to Step 9
8Test the APP sensor 1 signal circuit for a short to the APP sensor 3 signal circuit with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 10
9Test the APP sensor 1 signal circuit for a short to the APP sensor 2 signal circuit with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 10
10Turn OFF the ignition. Disconnect the APP sensor harness connector. Turn ON the ignition. Test for voltage at the APP sensor 1 5-volt reference circuit with a test lamp connected to ground. Does the test lamp illuminate?Go to Step 11Go to Step 16
11Connect the test lamp between the APP sensor 1 5-volt reference circuit and the APP sensor 1 low reference circuit. Does the test lamp illuminate?Go to Step 12Go to Step 17
12Connect a fused jumper wire between the APP sensor 1 signal circuit and the APP sensor 1 5-volt reference circuit. Observe the APP sensor 1 voltage parameter with a scan tool. Does the scan tool indicate voltage at the specified value?5 VGo to Step 18Go to Step 13
13Turn OFF the ignition. Disconnect the engine control module (ECM) harness connector that contains the APP sensor 1 signal circuit. Test the APP sensor 1 signal circuit for high resistance with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 20
14Turn OFF the ignition. Disconnect the ECM harness connector that contains the APP sensor 2 5-volt reference circuit. Test the APP sensor 2 5-volt reference circuit for high resistance with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 20
15Turn OFF the ignition. Disconnect the ECM harness connector that contains the APP sensor 2 low reference circuit. Test the APP sensor 2 low reference circuit for resistance with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 20
16Turn OFF the ignition. Disconnect the ECM harness connector that contains the APP sensor 1 5-volt reference circuit. Turn ON the ignition. Test the APP sensor 1 5-volt reference circuit for high resistance with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 20
17Turn OFF the ignition. Disconnect the ECM harness connector that contains the APP sensor 1 low reference circuit. Test the APP sensor 1 low reference circuit for resistance with a DMM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 20
18Inspect for poor connections at the harness connector of the APP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 19
19Replace the APP sensor assembly. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Did you complete the replacement?Go to Step 22
20Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems. Did you find and correct the condition?Go to Step 22Go to Step 21
21Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 22
22Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 23
23Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P2138

The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. The sensor is made up of 3 individual sensors within one housing. Three separate signal, low reference, and 5-volt reference circuits are used in order to interface the APP sensor with the engine control module (ECM). Each sensor has a unique functionality to determine the pedal position as shown in the table below. The ECM uses the APP sensor to determine the amount of acceleration or deceleration desired by the person driving the vehicle via the fuel injector control. If the ECM determines an out of range condition with the APP sensor 1 and APP sensor 3, DTC P2139 sets.

APP SensorActual Pedal Position% Depressed as Observed on a Scan ToolVoltage as Observed on a Scan Tool
1Pedal at rest0.52 - .80
1Pedal at full travel1002.12 - 2.78
2Pedal at rest04.25 - 4.53
2Pedal at full travel1002.24 - 2.93
3Pedal at rest03.95 - 4.13
3Pedal at full travel1002.69 - 3.16

APP Sensor Position Table

This diagnostic procedure supports the following DTC

DTC P2139 Accelerator Pedal Position (APP) Sensor 1-3 Correlation

  1. DTCs P0642, P0643, P0698, P0699, P2127, P2128, P2132, P2133 are not set.
  2. The ignition switch is in the Crank or Run position.
  3. The ignition voltage is between 7-16 volts.
  4. DTC P2139 runs continuously.
  1. The APP sensor 1 and the APP sensor 3 are more than 10 percent out of range of each other.
  2. The above condition is present for less than one second.
  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. If one or more APP sensor DTCs are set for a single APP sensor, the following occurs: The control module will not command Reduced Engine Power mode. The control module will use the remaining two APP sensors to calculate throttle response.
  5. If certain multiple APP sensor DTCs are set for more than one APP sensor, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to a predetermined value to limit the amount of throttle control. The message center displays Reduced Engine Power.
  6. If all three APP sensors are out of range, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to 0 percent. The control module only allows the engine to idle. The message center displays Reduced Engine Power.
  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.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. 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. Does the DTC fail this ignition?Go to Step 4Go to Step 3
3Select the DTC option using the scan tool. Lightly touch and move the related accelerator pedal position (APP) wiring harnesses and connectors while monitoring the DTC information. Did this DTC fail this ignition during the above test?Go to Step 4Go to Intermittent Conditions
4Is DTC P2138 also set?Go to DTC P2138Go to Step 5
5Turn OFF the ignition. Disconnect the APP sensor harness connector. Turn ON the ignition. Test for voltage at the APP sensor 3, 5-volt reference circuit with a test lamp connected to ground. Does the test lamp illuminate?Go to Step 6Go to Step 10
6Connect a test lamp between the APP sensor 3, 5-volt reference circuit and the APP sensor 3 low reference circuit. Does the test lamp illuminate?Go to Step 7Go to Step 12
7Disconnect the test lamp. With the APP sensor harness connector still disconnected, observe the APP sensor 1 and the APP sensor 3 voltage parameters with a scan tool. Are both APP sensor 2 and 3 voltages above the specified value?4 VGo to Step 8Go to Step 15
8Probe the APP sensor 1 signal circuit with a test lamp connected to ground. Observe the APP sensor 1 and the APP sensor 3 voltage parameters with a scan tool. Are both APP sensor 1 and 3 voltages below the specified value?1 VGo to Step 9Go to Step 11
9Test the APP sensor 1 signal circuit for a short to the APP sensor 3 signal circuit with a DMM. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 17Go to Step 15
10Turn OFF the ignition. Disconnect the engine control module (ECM) harness connector that contains the APP sensor 3, 5-volt reference circuit. Test the APP sensor 3, 5-volt reference circuit for high resistance with a DMM. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 17Go to Step 15
11Turn OFF the ignition. Disconnect the ECM harness connector that contains the APP sensor 3 signal circuit. Turn ON the ignition. Test the APP sensor 3 signal circuit for high resistance with a DMM. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 17Go to Step 13
12Turn OFF the ignition. Disconnect the ECM harness connector that contains the APP sensor 3 low reference circuit. Test the APP sensor 3 low reference circuit for high resistance with a DMM. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 17Go to Step 15
13Inspect for poor connections at the harness connector of the APP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals . Did you find and correct the condition?Go to Step 17Go to Step 14
14Replace the APP sensor assembly. Refer to Accelerator Pedal Position (APP) Sensor Replacement . Did you complete the replacement?Go to Step 17
15Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals . Did you find and correct the condition?Go to Step 17Go to Step 16
16Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?Go to Step 17
17Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 18
18Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - VehicleSystem OK

DTC P2139

The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. The sensor is made up of 3 individual sensors within one housing. Three separate signal, low reference, and 5-volt reference circuits are used in order to interface the APP sensor with the engine control module (ECM). Each sensor has a unique functionality to determine the pedal position as shown in the table below. The ECM uses the APP sensor to determine the amount of acceleration or deceleration desired by the person driving the vehicle via the fuel injector control. If the ECM determines an out of range condition with the APP sensor 2 and APP sensor 3, DTC P2140 sets.

APP SensorActual Pedal Position% Depressed as Observed on a Scan ToolVoltage as Observed on a Scan Tool
1Pedal at rest0.52 - .80
1Pedal at full travel1002.12 - 2.78
2Pedal at rest04.25 - 4.53
2Pedal at full travel1002.24 - 2.93
3Pedal at rest03.95 - 4.13
3Pedal at full travel1002.69 - 3.16

APP Sensor Position Table

This diagnostic procedure supports the following DTC

DTC P2140 Accelerator Pedal Position (APP) Sensor 2-3 Correlation

  1. DTCs P0652, P0653, P0698, P0699, P2122, P2123, P2132, or P2133 are not set.
  2. The ignition switch is in the Crank or Run position.
  3. The ignition voltage is between 7-16 volts.
  4. DTC P2140 runs continuously.
  1. The APP sensor 2 and the APP sensor 3 are more than 10 percent out of range of each other.
  2. The above condition is present for less than one second.
  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. If one or more APP sensor DTCs are set for a single APP sensor, the following occurs: The control module will not command Reduced Engine Power mode. The control module will use the remaining two APP sensors to calculate throttle response.
  5. If certain multiple APP sensor DTCs are set for more than one APP sensor, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to a predetermined value to limit the amount of throttle control. The message center displays Reduced Engine Power.
  6. If all three APP sensors are out of range, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to 0 percent. The control module only allows the engine to idle. The message center displays Reduced Engine Power.
  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.
StepActionYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Is DTC P2138 also set?Go to DTC P2138Go to Step 3
3Is DTC P2139 also set?Go to DTC P2139

DTC P2140

The fuel injection control module (FICM) supplies high voltage to each fuel injector on the ignition voltage circuits. The FICM energizes each fuel injector by grounding the command circuit between the FICM and the fuel injector. The FICM monitors the status of the ignition 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 ignition 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 DTC

DTC P2146 Injector Positive Voltage Relay Control Circuit Group 1

  1. The ignition is ON.
  2. DTC U0073 or U0105 is not set.

The engine control module (ECM) detects a circuit fault related to the high voltage circuit to cylinders 1, 4, 6, and 7.

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

  1. 2: This step determines if a wiring or injector condition caused this DTC to set. If DTC P2146 set alone, an internal FICM fault is the cause.
StepActionYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Is DTC P0201, P0204, P0206, or P0207 also set?Go to DTC P0201-P0208Go to Step 3
3Replace the fuel injection control module (FICM). Refer to Fuel Injection Control Module Replacement . Did you complete the replacement?Go to Step 4
4Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 5
5Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P2146

The fuel injection control module (FICM) supplies high voltage to each fuel injector on the ignition voltage circuits. The FICM energizes each fuel injector by grounding the command circuit between the FICM and the fuel injector. The FICM monitors the status of the ignition 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 ignition 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 DTC

DTC P2149 Injector Positive Voltage Relay Control Circuit Group 2

  1. The ignition is ON.
  2. DTC U0073 or U0105 are not set.

The engine control module (ECM) detects a circuit fault related to the high voltage circuit to cylinders 2, 3, 5, and 8.

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

  1. 2: This step determines if a wiring or injector condition caused this DTC to set. If DTC P2149 sets alone, an internal FICM fault is the cause.
StepActionYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Is DTCs P0202, P0203, P0205, or P0208 also set?Go to DTC P0201-P0208Go to Step 3
3Replace the fuel injection control module (FICM). Refer to Fuel Injection Control Module Replacement . Did you complete the replacement?Go to Step 4
4Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 5
5Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P2149

The barometric pressure (BARO) sensor measures the pressure of the atmosphere. This pressure is affected by altitude and weather conditions. A diaphragm within the BARO sensor is displaced by the pressure changes that occur from varying altitudes and weather conditions. The sensor translates this action into electrical resistance. The BARO 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 BARO sensor provides a signal voltage to the ECM, relative to the pressure changes on the BARO sensor signal circuit. The ECM converts the signal voltage input to a pressure value.

Changes in BARO due to weather are relatively small, while changes due to altitude are significant. Pressure can range from 56 kPa at an altitude of 4 267 meters (14,000 feet), to 105 kPa at or below sea level. The BARO sensor has a range of 8-207 kPa. The ECM uses the BARO sensor input for fuel delivery and other diagnostics.

Within the ECM, the diagnostic compares the BARO sensor input to the boost pressure sensor input. If the ECM detects that the inputs are not within a specified amount of each other, DTC P2227 sets.

This diagnostic procedure supports the following DTC

DTC P2227 Barometric Pressure (BARO) Sensor Performance

  1. DTCs P0101, P0102, P0103, P0116, P0117, P0118, P0237, P0238, P0299, P0335, P0336, P0500, P2228, and P2229 are not set.
  2. The engine speed is between 580-900 RPM.
  3. The engine run time is more than 8 seconds.
  4. The vehicle speed is less than 40 km/h (25 mph).
  5. The accelerator pedal position (APP) is less than 69 percent.
  6. The engine coolant temperature is more than 20°C (68°F).
  7. The mass air flow (MAF) is less than 50 g/s.
  8. The power take-off (PTO) is not active.
  9. The above conditions are met for 5 seconds.
  10. DTC P2227 runs continuously once the above conditions are met.
  11. DTC P2227 runs continuously once the above conditions are met.

The ECM detects that the difference between the BARO pressure and the boost pressure is more than 15 kPa for 6 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 (DIC), if equipped, may display a message.
  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. 3: This step tests the ability of the boost pressure sensor to correctly indicate barometric pressure.
  2. 8: This step tests the circuits and the controller output.
  3. 14: This step tests the circuits and the controller output.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Turn ON the ignition, with the engine OFF. Observe the BARO parameter with a scan tool. Compare the barometric pressure (BARO) value to the range specified in the altitude vs. barometric pressure table. Refer to Altitude vs Barometric Pressure . Is the BARO parameter within the range specified in the altitude vs. barometric pressure table?Go to Step 3Go to Step 7
3Observe the Boost Pressure Sensor parameter with a scan tool. Compare the Boost Pressure Sensor value to the range specified in the altitude vs. barometric pressure table. Refer to Altitude vs Barometric Pressure . Is the Boost Pressure Sensor parameter within the range specified in the altitude vs. barometric pressure table?Go to Step 4Go to Step 13
4Connect a J 23738-A Mityvac to the BARO sensor port. Observe the BARO parameter with a scan tool. Apply vacuum with the J 23738-A until 10 inches Hg is reached. Does the BARO parameter decrease?Go to Step 5Go to Step 24
5Start the engine. Operate the vehicle, at a consistent altitude, within the Conditions for Running the DTC. Observe the BARO parameter with a scan tool. Does the BARO parameter change more than the specified value?15 kPaGo to Step 7Go to Step 6
6Operate the vehicle, at a consistent altitude, within the Conditions for Running the DTC. Observe the Boost Pressure Sensor parameter and the BARO parameter with a scan tool. Is the difference between the Boost Pressure Sensor parameter and the BARO parameter more than the specified value?15 kPaGo to Step 13Go to Intermittent Conditions
7Test for an intermittent and for a poor connection at the BARO sensor connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 27Go to Step 8
8Disconnect the BARO sensor. Measure the amperage between the 5-volt reference circuit and the low reference circuit, at the BARO sensor connector, with a DMM. Is the amperage more than the specified value?170 mAGo to Step 9Go to Step 10
9Connect a jumper wire between the 5-volt reference circuit and the BARO sensor signal circuit at the BARO sensor connector. Observe the BARO parameter with a scan tool. Is the pressure more than the specified value?205 kPaGo to Step 24Go to Step 19
10Test for an intermittent and for a poor connection at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 27Go to Step 11
11Disconnect the ECM. Measure the resistance of the 5-volt reference circuit between the BARO sensor and the ECM, with a DMM. Is the resistance more than the specified value?5 ohmsGo to Step 23Go to Step 12
12Measure the resistance of the low reference circuit between the BARO sensor and the ECM, with a DMM. Is the resistance more than the specified value?5 ohmsGo to Step 23Go to Step 26
13Test for an intermittent and for a poor connection at the boost pressure sensor connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 27Go to Step 14
14Disconnect the boost pressure sensor. Measure the amperage between the 5-volt reference circuit and the low reference circuit, at the boost pressure sensor connector, with a DMM. Is the amperage more than the specified value?170 mAGo to Step 15Go to Step 16
15Connect a jumper wire between the 5-volt reference circuit and the signal circuit of the boost pressure sensor at the connector. Observe the Boost Pressure Sensor parameter with the scan tool. Is the pressure more than the specified value?254 kPa (36 psi)Go to Step 25Go to Step 20
16Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 27Go to Step 17
17Disconnect the ECM. Measure the resistance of the 5-volt reference circuit between the boost pressure sensor and the ECM, with a DMM. Is the resistance more than the specified value?5 ohmsGo to Step 23Go to Step 18
18Measure the resistance of the low reference circuit between the boost pressure sensor and the ECM, with a DMM. Is the resistance more than the specified value?5 ohmsGo to Step 23Go to Step 26
19Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 27Go to Step 21
20Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 27Go to Step 22
21Disconnect the ECM. Measure the resistance of the BARO sensor signal circuit between the BARO sensor and the ECM, with a DMM. Is the resistance more than the specified value?5 ohmsGo to Step 23Go to Step 26
22Disconnect the ECM. Measure the resistance of the boost pressure sensor signal circuit between the boost pressure sensor and the ECM, with a DMM. Is the resistance more than the specified value?5 ohmsGo to Step 23Go to Step 26
23Repair the high resistance in the circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 27
24Replace the BARO sensor. Refer to Barometric Pressure (BARO) Sensor Replacement . Did you complete the replacement?Go to Step 27
25Replace the boost pressure sensor. Refer to Boost Pressure Sensor Replacement . Did you complete the replacement?Go to Step 27
26Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 27
27Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition?Go to Step 2Go to Step 28
28Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P2227

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