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Engine Controls Diagnosis - 3.4l (DTC p0506 - DTC p1640) Buick Rendezvous I

Testing & Diagnostics ~9009 words

Circuit Description

The engine idle speed is controlled by the idle air control (IAC) valve. The IAC valve is on the throttle body. The IAC valve pintle moves in and out of an idle air passage bore to control air flow around the throttle plate. The IAC valve consists of a movable pintle, driven by a gear attached to an electric motor called a stepper motor. The stepper motor is capable of highly accurate rotation, or of movement, called steps. The stepper motor has 2 separate windings that are called coils. Each coil is supplied current by 2 circuits from the powertrain control module (PCM). When the PCM changes polarity of a coil, the stepper motor moves one step. The PCM uses a predetermined number of counts to determine the IAC pintle position. Observe IAC counts with a scan tool. The IAC counts will increment up or down as the PCM attempts to change the IAC valve pintle position. An IAC Reset will occur when the ignition key is turned OFF. First, the PCM will seat the IAC pintle in the idle air passage bore. Second, the PCM will retract the pintle a predetermined number of counts to allow for efficient engine start-up. If the engine idle speed is out of range for a calibrated period of time, an idle speed diagnostic trouble code (DTC) sets.

Conditions For Running the DTC

  1. DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0171, P0172, P0201, P0202, P0203, P0204, P0205, P0206, P0300, P0401, P0403, P0404, P0405, P502, are not set.
  2. The Engine Run Time parameter is more than 2 minutes.
  3. The ECT Sensor parameter is more than 70°C (158°F).
  4. The IAT Sensor parameter is more than -18°C (-0.4°F).
  5. The BARO parameter is more than 70 kPa.
  6. The Ignition 1 Signal parameter is between 9-18 volts.
  7. The TP Sensor parameter is less than 1.5 percent.
  8. The Vehicle Speed Sensor parameter is less than 5 km/h (3 mph).
  9. The above conditions are met for more than 8 seconds.

Conditions for Setting the DTC

  1. The Engine Speed parameter is 100 RPM less than the Desired Idle Speed parameter for more than 8 seconds for each test.
  2. The PCM detects the IAC test failed 4 consecutive times in one ignition cycle.
  3. The vehicle must enter the above criteria and then leave the criteria for 1 second in order to complete one IAC test.

Action Taken When the DTC Sets

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

Conditions for Clearing the MIL/DTC

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

Diagnostic Aids

Inspect for the following conditions

  1. High resistance in an IAC valve control circuit
  2. Restricted air intake system
  3. Proper operation and installation of all air intake components
  4. Collapsed, clogged, or loose air intake ducts
  5. A clogged air filter
  6. Proper operation of the mass air flow (MAF) sensor, if equipped
  7. A tampered with or damaged throttle stop screw
  8. A tampered with or damaged throttle plate, throttle shaft, or throttle linkage
  9. Objects blocking the IAC passage or throttle bore
  10. Excessive deposits in the IAC passage or on the IAC pintle
  11. Excessive deposits in the throttle bore or on the throttle plate
  12. Vacuum leaks
  13. A low or unstable idle condition could be caused by a non-IAC system problem that can not be overcome by the IAC valve-Refer to «Symptoms - Engine Controls»(/buick/rendezvous/i-2001-2007/remont/testing-diagnostics/#engine-controls-34l-troubleshooting) .

If the problem is determined to be intermittent, refer to Intermittent Conditions .

Test Description

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

  1. 5: This test will determine the ability of the PCM and the IAC valve control circuits to control the IAC valve.
  2. 7: This test will determine the ability of the PCM to provide the IAC valve control circuits with a ground. On a normal operating system, the test lamp should not flash while the IAC Counts are incrementing.
StepActionYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2IMPORTANT: Ensure that the Engine Speed parameter stabilizes with each Commanded RPM change to determine if the engine speed stays within 100 RPM of the Commanded RPM. Set the parking brake and block the drive wheels. Start the engine. Turn OFF all accessories. Slowly increment engine speed to 1,700 RPM, then to 600 RPM, then to 1,700 RPM with the scan tool RPM control function. Exit the RPM Control function. Did the Engine Speed parameter stabilize within 100 RPM of the commanded RPM?Go to Step 3Go to Step 4
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?Go to Step 4Go to Diagnostic Aids
4Turn OFF the ignition. Disconnect the IAC valve. Connect the J 37027-1A IAC Motor Driver to the IAC valve. Start the engine. Command the IAC valve in until 600 RPM is reached with the J 37027-1A . Command the IAC valve out until 1,700 RPM is reached with the J 37027-1A . Return the engine speed to the Desired Idle Speed parameter. Did the Engine Speed parameter steadily decrease to 600 RPM and steadily increase to 1,700 RPM when the IAC valve was commanded in and out?Go to Step 5Go to Step 11
5Connect a test lamp between one of the IAC valve control circuits and a good ground. Start the engine. Observe the IAC Counts parameter with a scan tool. Command high RPM with the J 37027-1A until the IAC Counts parameter starts to increment. Command low RPM with the J 37027-1A until the IAC Counts parameter starts to increment. Return the Engine Speed parameter to the Desired Idle Speed parameter. Repeat the above procedure for the other three IAC valve control circuits. Did the test lamp remain ON, never flashing, while the IAC Counts were incrementing for any of the IAC valve control circuits?Go to Step 10Go to Step 6
6Did the test lamp remain OFF, never flashing, while the IAC Counts were incrementing for any of the IAC valve control circuits?Go to Step 9Go to Step 7
7Connect a test lamp between the IAC coil A low circuit and the IAC coil A high circuit. Observe the IAC Counts parameter with a scan tool and observe the test lamp. Command high RPM with the J 37027-1A until the IAC Counts parameter starts to increment. Command low RPM with the J 37027-1A until the IAC Counts parameter starts to increment. Return the Engine Speed parameter to the Desired Idle Speed parameter. Repeat the above procedure with the test lamp connected between the IAC coil B low control circuit and the IAC coil B high control circuit. Did the test lamp stay illuminated and never flashing while the IAC Counts were incrementing for any of the IAC valve control circuits?Go to Step 8Go to Step 16
8Test for an intermittent and for a poor connection at the IAC valve. 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 17Go to Step 12
9Turn OFF the ignition. Disconnect the PCM. Test the circuit where the test lamp remained OFF for the following conditions: An open circuit A short to ground A short to another IAC valve control circuit-Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 17Go to Step 12
10Turn ON the ignition. Test the IAC valve control circuit where the test lamp remained ON for the following conditions: A short to voltage A short to another IAC valve control circuit-Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 17Go to Step 12
11Inspect for the following conditions: Throttle body damage and tampering Throttle lever screw tampering, if equipped Restricted air intake system-Inspect for a possible collapsed/clogged air intake duct, before and after the air filter element, restricted air filter element, restriction at the throttle body intake screen, if equipped. Remove the IAC valve. Refer to Idle Air Control (IAC) Valve Replacement . Inspect for the following conditions: A clogged IAC passage Excessive deposits on the throttle plate Excessive deposits in the throttle bore Excessive deposits on IAC valve pintle Did you find and correct the condition?Go to Step 17Go to Step 14
12Test for an intermittent and for a poor connection at the PCM. 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 17Go to Step 13
13Disconnect the PCM. Test all IAC valve control circuits for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 17Go to Step 16
14Test for an intermittent and for a poor connection at the IAC valve. 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 17Go to Step 15
15Replace the IAC valve. Refer to Idle Air Control (IAC) Valve Replacement . Did you complete the replacement?Go to Step 17
16Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . 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) ListSystem OK
IMPORTANT
Ensure that the Engine Speed parameter stabilizes with each Commanded RPM change to determine if the engine speed stays within 100 RPM of the Commanded RPM.

DTC P0506

The engine idle speed is controlled by the idle air control (IAC) valve. The IAC valve is on the throttle body. The IAC valve pintle moves in and out of an idle air passage bore to control air flow around the throttle plate. The IAC valve consists of a movable pintle, driven by a gear attached to an electric motor called a stepper motor. The stepper motor is capable of highly accurate rotation, or of movement, called steps. The stepper motor has 2 separate windings that are called coils. Each coil is supplied current by 2 circuits from the powertrain control module (PCM). When the PCM changes polarity of a coil, the stepper motor moves one step. The PCM uses a predetermined number of counts to determine the IAC pintle position. Observe IAC counts with a scan tool. The IAC counts will increment up or down as the PCM attempts to change the IAC valve pintle position. An IAC Reset will occur when the ignition key is turned OFF. First, the PCM will seat the IAC pintle in the idle air passage bore. Second, the PCM will retract the pintle a predetermined number of counts to allow for efficient engine start-up. If the engine idle speed is out of range for a calibrated period of time, an idle speed diagnostic trouble code (DTC) sets.

  1. DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0171, P0172, P0201, P0202, P0203, P0204, P0205, P0206, P0300, P0401, P0403, P0404, P0405, P502, are not set.
  2. The Engine Run Time parameter is more than 2 minutes.
  3. The ECT Sensor parameter is more than 70°C (158°F).
  4. The IAT Sensor parameter is more than -18°C (-0.4°F).
  5. The BARO parameter is more than 70 kPa.
  6. The Ignition 1 Signal parameter is between 9-18 volts.
  7. The TP Sensor parameter is less than 1.5 percent.
  8. The Vehicle Speed Sensor parameter is less than 5 km/h (3 mph).
  9. The above conditions are met for more than 8 seconds.
  1. The Engine Speed parameter is 150 RPM more than the Desired Idle Speed parameter for more than 8 seconds for each test.
  2. The PCM detects the IAC test failed 4 consecutive times in one ignition cycle.
  3. The vehicle must enter the above criteria and then leave the criteria for 1 second in order to complete one IAC test.
  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.

Inspect for the following conditions

  1. High resistance in an IAC valve control circuit
  2. The correct positive crankcase ventilation (PCV) valve, properly installed and proper operation of the PCV valve
  3. Proper operation and installation of all air intake components
  4. Proper installation and operation of the mass air flow (MAF) sensor, if equipped
  5. A tampered with or damaged throttle stop screw
  6. A tampered with or damaged throttle plate, throttle shaft, throttle linkage, or cruise control linkage, if equipped
  7. A skewed high TP sensor
  8. Excessive deposits in the IAC passage or on the IAC pintle
  9. Excessive deposits in the throttle bore or on the throttle plate
  10. Vacuum leaks
  11. A high or unstable idle condition could be caused by a non-IAC system problem that can not be overcome by the IAC valve. Refer to «Symptoms - Engine Controls»(/buick/rendezvous/i-2001-2007/remont/testing-diagnostics/#engine-controls-34l-troubleshooting) .
  12. If the problem is determined to be intermittent, refer to «Intermittent Conditions»(/buick/rendezvous/i-2001-2007/remont/testing-diagnostics/#engine-controls-34l-troubleshooting__intermittent-conditions) .

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

  1. 5: This test will determine the ability of the PCM and IAC valve control circuits to control the IAC valve.
  2. 7: This test will determine the ability of the PCM to provide the IAC valve control circuits with a ground. On a normally operating system, the test lamp should not flash while the IAC Counts are incrementing.
StepActionYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2IMPORTANT: Ensure that the Engine Speed parameter stabilizes with each Commanded RPM change to determine if engine speed stays within 150 RPM of the Commanded RPM. Set the parking brake and block the drive wheels. Start the engine. Turn OFF all accessories. Slowly increment the engine speed to 1,700 RPM, then to 600 RPM, then to 1,700 RPM with the scan tool RPM Control function. Exit the RPM control function. Did the Engine Speed parameter stabilize within 150 RPM of the Commanded RPM?Go to Step 3Go to Step 4
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?Go to Step 4Go to Diagnostic Aids
4Turn OFF the ignition. Disconnect the IAC valve. Connect a J 37027-1A IAC Motor Driver to the IAC valve. Start the engine. Command the IAC valve in until 600 RPM is reached with the J 37027-1A . Command the IAC valve out until 1,700 RPM is reached with the J 37027-1A . Return the engine speed to the Desired Idle Speed parameter. Did the Engine Speed parameter steadily decrease to 600 RPM and steadily increase to 1,700 RPM when the IAC valve was commanded in and out?Go to Step 5Go to Step 11
5Connect the test lamp between one of the IAC valve control circuits and a good ground. Start the engine. Observe the IAC Counts parameter with a scan tool and observe the test lamp. Command high RPM with the J 37027-1A until the IAC Counts parameter starts to increment. Command low RPM with the J 37027-1A until the IAC Counts parameter starts to increment. Return the Engine Speed parameter to the Desired Idle Speed parameter. Repeat the above procedure for the other three IAC valve control circuits. Did the test lamp remain ON, never flashing, while the IAC Counts were incrementing for any of the IAC valve control circuits?Go to Step 10Go to Step 6
6Did the test lamp remain OFF, never flashing, while the IAC Counts were incrementing for any of the IAC valve control circuits?Go to Step 9Go to Step 7
7Connect a test lamp between the IAC coil A low control circuit and the IAC coil A high control circuit. Observe the IAC Counts parameter with a scan tool and observe the test lamp. Command high RPM with the J 37027-1A until the IAC Counts parameter starts to the increment. Command low RPM with the J 37027-1A until the IAC Counts parameter starts to increment. Return the Engine Speed parameter to the Desired Idle Speed parameter as indicated on the scan tool data list. Repeat the above procedure with the test lamp connected between the IAC coil B low control circuit and the IAC coil B high control circuit. Did the test lamp stay illuminated and never flashing while the IAC Counts were incrementing for any of the IAC valve control circuits?Go to Step 8Go to Step 16
8Test for an intermittent and for a poor connection at the IAC valve. 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 17Go to Step 12
9Turn OFF the ignition. Disconnect the PCM. Test the IAC valve control circuit where the test lamp remained OFF for the following conditions: An open circuit A short to ground A short to another IAC valve control circuit-Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 17Go to Step 12
10Turn ON the ignition. Test the IAC valve control circuit where the test lamp remained ON for the following conditions: A short to voltage A short to another IAC valve control circuit-Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 17Go to Step 12
11Inspect for the following conditions: Throttle body damage and tampering Throttle lever screw tampering, if equipped Vacuum leaks Faulty, incorrectly installed PCV valve and hose, if equipped Throttle shaft binding Throttle linkage or cruise control linkage binding, if equipped Remove the IAC valve. Refer to Idle Air Control (IAC) Valve Replacement . Inspect for the following conditions: Debris in the IAC passage Excessive deposits on the throttle plate Excessive deposits in the throttle bore Excessive deposits on IAC valve pintle Did you find and correct the condition?Go to Step 17Go to Step 14
12Test for an intermittent and for a poor connection at the PCM. 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 17Go to Step 13
13Disconnect the PCM. Test all IAC valve control circuits for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 17Go to Step 16
14Test for an intermittent and for a poor connection at the IAC valve. 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 17Go to Step 15
15Replace the IAC valve. Refer to Idle Air Control (IAC) Valve Replacement . Did you complete the replacement?Go to Step 17
16Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . 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) ListSystem OK
IMPORTANT
Ensure that the Engine Speed parameter stabilizes with each Commanded RPM change to determine if engine speed stays within 150 RPM of the Commanded RPM.

DTC P0507

Description

This diagnostic applies to internal microprocessor integrity conditions within the powertrain control module (PCM). This diagnostic also addresses if the PCM is not programmed.

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

  1. 2: A DTC P0602 indicates the PCM is not programmed.
StepActionYesNo
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Is DTC P0602 set?Go to Step 3Go to Step 5
3Program the PCM. Refer to Service Programming System (SPS) in Programming. Does DTC P0602 reset?Go to Step 4Go to Step 6
4Ensure that all tool connections are secure. Ensure that the programming equipment is operating correctly. Ensure that the correct software/calibration package is used. Attempt to program the PCM. Refer to Service Programming System (SPS) in Programming. Does DTC P0602 reset?Go to Step 5Go to Step 6
5Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . Did you complete the replacement?Go to Step 6
6Start the engine. 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) ListSystem OK

DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681, P1683, or P2610

The powertrain control module (PCM) provides 5 volts to the following sensors

  1. The manifold absolute pressure (MAP) sensor
  2. The exhaust gas recirculation (EGR) valve
  3. The fuel tank pressure (FTP) sensor
  4. The throttle position (TP) sensor

These 5-volt reference circuits are independent of each other outside the PCM, but are bussed together inside the PCM. Therefore a circuit condition on one sensor 5-volt reference circuit may affect the other sensor 5-volt reference circuits. The PCM monitors the voltage on the 5-volt reference circuit. If the PCM detects that the voltage is out of tolerance, DTC P0641 sets.

The engine is running.

  1. The PCM detects a voltage out of tolerance condition on the 5-volt reference circuit.
  2. The above condition is present for more than 10 seconds.
  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.
  1. If any sensor using a 5-volt bias voltage, such as the intake air temperature (IAT) sensor or fuel sensor, is shorted to voltage, DTC P0651 may set in addition to DTC P0641.
  2. For an intermittent condition, refer to «Intermittent Conditions»(/buick/rendezvous/i-2001-2007/remont/testing-diagnostics/#engine-controls-34l-troubleshooting__intermittent-conditions) .
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
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 exhaust gas recirculation (EGR) valve. Turn ON the ignition, with the engine OFF. Command the EGR solenoid to 100 percent with a scan tool. Measure the voltage from the 5-volt reference circuit to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems. Is the voltage within the specified range?4.8-5.2 VGo to Step 5Go to Step 4
4Is the voltage measured in the previous step more than the specified value?5.2 VGo to Step 8Go to Step 6
5Connect the EGR valve. Disconnect the manifold absolute pressure (MAP) sensor. Command the EGR solenoid to 100 percent with a scan tool. Measure the voltage from the 5-volt reference circuit of the MAP sensor to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems. Is the voltage within the specified range?4.8-5.2 VGo to Diagnostic AidsGo to Step 11
6Monitor a DMM while disconnecting all other devices connected to the 5-volt reference circuit, one at a time. Refer to Engine Controls Component Views . If voltage changes when one of the devices are disconnected, replace the component. Refer to the appropriate replacement procedure below: The MAP sensor-Refer to Manifold Absolute Pressure (MAP) Sensor Replacement . The FTP sensor-Refer to Fuel Tank Pressure Sensor Replacement . The throttle position (TP) sensor-Refer to Throttle Position (TP) Sensor Replacement . Was a component replaced?Go to Step 13Go to Step 7
7Turn OFF the ignition. Disconnect the powertrain control module (PCM). Test the 5-volt reference circuit for a short to ground or any sensor low reference circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 12
8Monitor the DMM while disconnecting the MAP sensor and fuel tank pressure (FTP) sensor, one at a time. Refer to Engine Controls Component Views . If the voltage returns to within the specified value when one of the devices is disconnected, test that sensors signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?4.8-5.2 VGo to Step 13Go to Step 9
9Test the 5-volt reference circuits 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 13Go to Step 10
10Test for a short between the EGR 5-volt reference circuit and the EGR solenoid high control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 13Go to Step 12
11Replace the EGR valve. Refer to Exhaust Gas Recirculation (EGR) Valve Replacement . Did you complete the replacement?Go to Step 13
12Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . 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) ListSystem OK

DTC P0641

The malfunction indicator lamp (MIL) is located on the instrument panel cluster (IPC). The MIL informs the driver that an emission system fault has occurred and that the engine control system requires service. The control module monitors the MIL control circuit for conditions that are incorrect for the commanded state of the MIL. For example, a failure condition exists if the control module detects low voltage when the MIL is commanded OFF, or high voltage when the MIL is commanded ON. If the control module detects an improper voltage on the MIL control circuit, DTC P0650 will set.

The ignition is ON.

  1. The control module detects that the commanded state of the MIL driver and the actual state of the control circuit do not match.
  2. The conditions are present for a minimum of 30 seconds.

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

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

  1. 5: This step tests for a short to ground in the MIL control circuit. With the powertrain control module (PCM) disconnected and the ignition ON, the MIL should be OFF.
  2. 6: This step tests for a short to voltage on the MIL control circuit. With the fuse removed, there should be no voltage on the MIL control circuit.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Verify whether the instrument cluster is operational. If the instrument panel (I/P) is completely inoperative, refer to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gages and Console. Command the MIL ON and OFF with a scan tool. Does the MIL turn ON and OFF when commanded with a scan tool?Go to Step 3Go to Step 4
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. Does the DTC fail this ignition?Go to Step 4Go to Intermittent Conditions
4Inspect the fuse that supplies ignition voltage to the MIL. Is the fuse open?Go to Step 12Go to Step 5
5Turn OFF the ignition. Disconnect the powertrain control module (PCM). Refer to Powertrain Control Module (PCM) Replacement . Turn ON the ignition. Is the MIL OFF?Go to Step 6Go to Step 13
6Turn OFF the ignition. Remove the fuse that supplies voltage to the MIL. Turn ON the ignition, with the engine OFF. Measure the voltage from the MIL control circuit to a good ground. Is the voltage less than the specified value?0.3 VGo to Step 7Go to Step 14
7Turn OFF the ignition. Install the fuse that supplies voltage to the MIL. Turn ON the ignition, with the engine OFF. Connect a 3-amp fused jumper wire between the MIL control circuit of the PCM and a good ground. Is the MIL illuminated?Go to Step 11Go to Step 8
8Turn OFF the ignition. Remove the instrument panel cluster (IPC). Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel, Gages, and Console. Probe the MIL battery positive voltage circuit of the IPC harness connector with a test lamp that is connected to a good ground. Does the test lamp illuminate?Go to Step 9Go to Step 15
9Test the MIL control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct a condition?Go to Step 18Go to Step 10
10Test for an intermittent and for a poor connection at the IPC. 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 18Go to Step 16
11Test for an intermittent and for a poor connection at the PCM. 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 18Go to Step 17
12Repair the short to ground in the battery positive voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 18
13Repair the short to ground in the MIL control circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 18
14Repair the short to voltage in the MIL control circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 18
15Repair the open in the MIL ignition voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 18
16Replace the IPC. Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement?Go to Step 18
17Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . Did you complete the replacement?Go to Step 18
18Clear 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 19
19Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) ListSystem OK

DTC P0650

The powertrain control module (PCM) provides 5 volts to the air conditioning (A/C) refrigerant pressure sensor. The PCM monitors the voltage on the 5-volt reference circuit. If the PCM detects that the voltage is out of tolerance, DTC P0651 sets.

The engine is running.

  1. The PCM detects a voltage out of tolerance condition on the 5-volt reference circuit.
  2. The above condition is present for longer than 10 seconds.
  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.
  1. If any sensor using a 5-volt bias voltage, such as the intake air temperature (IAT) sensor or fuel sensor, is shorted to voltage, DTC P0641 may set in addition to DTC P0651.
  2. For an intermittent condition, refer to «Intermittent Conditions»(/buick/rendezvous/i-2001-2007/remont/testing-diagnostics/#engine-controls-34l-troubleshooting__intermittent-conditions) .
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you complete the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
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 Diagnostic Aids
3Turn OFF the ignition. Disconnect the air conditioning (A/C) refrigerant pressure sensor. Turn ON the ignition, with the engine OFF. Measure the voltage from the 5-volt reference circuit of the A/C refrigerant pressure sensor to a good ground with a DMM. Is the voltage within the specified range?4.8-5.2 VGo to Step 9Go to Step 4
4Is the voltage measured in the previous step more than the specified value?5.2 VGo to Step 5Go to Step 8
5Turn OFF the ignition. Disconnect the powertrain control module (PCM). Turn ON the ignition, with the engine OFF. Measure the voltage from the 5-volt reference circuit of the A/C refrigerant pressure sensor to a good ground with a DMM. Is the voltage more than the specified value?0 VGo to Step 6Go to Step 7
6Test the 5-volt reference circuit for a short to voltage. Refer to Circuit Testing in Wiring Systems. Did you find and correct the condition?Go to Step 11
7Test the 5-volt reference circuit for a short to any other circuit within the harness to the PCM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 10
8Turn OFF the ignition. Disconnect the PCM. Test the 5-volt reference circuit for a short to ground or a short to any other circuit within the harness to the PCM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 10
9Replace the A/C refrigerant pressure sensor. Refer to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement in Heating, Ventilation, and Air Conditioning. Did you complete the replacement?Go to Step 11
10Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . 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) ListSystem OK

DTC P0651

The manifold absolute pressure (MAP) sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The MAP sensor has the following circuits

  1. 5-volt reference circuit
  2. Low reference circuit
  3. MAP sensor signal circuit

The powertrain control module (PCM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The PCM also provides a ground on the low reference circuit. The MAP sensor provides a signal to the PCM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The PCM should detect a low signal voltage at a low MAP, such as during an idle or a deceleration. The PCM should detect a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at a wide open throttle (WOT). The MAP sensor is also used in order to determine the barometric pressure (BARO). This occurs when the ignition switch is turned ON, with the engine OFF. The BARO reading may also be updated whenever the engine is operated at WOT. The PCM monitors the MAP sensor signal for voltage outside of the normal range.

If the PCM detects a MAP sensor signal voltage that is intermittently high, DTC P1106 sets.

  1. DTCs P0121, P0122, or P0123 are not set.
  2. The engine has been running for a period of time that is determined by the startup coolant temperature. The time ranges from 2 minutes at less than -30°C (-22°F) to 1 second at more than 30°C (86°F).
  3. The throttle angle is less than 2 percent when the engine speed is less than 3,000 RPM. OR
  4. The throttle angle is less than 30 percent when the engine speed is more than 3,000 RPM.

The PCM detects that the MAP sensor voltage is intermittently more than 4.2 volts.

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

Conditions for Clearing the DTC

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

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

  1. 3: Many intermittent open or shorted circuits occur with harness/connector movement caused by vibration, by engine torque, and by bumps. This step attempts to recreate this condition.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Start the engine. Monitor the diagnostic trouble code (DTC) information with the scan tool. Does the scan tool display DTC P0641 or P0108 set?Go to Diagnostic Trouble Code (DTC) ListGo to Step 3
3Observe the MAP sensor parameter with the scan tool. Attempt to induce the fault that set the DTC by manipulating the following items: The MAP sensor wiring harness The MAP sensor connector The PCM connector Refer to Inducing Intermittent Fault Conditions in Wiring Systems and Intermittent Conditions .Is the MAP sensor voltage affected during any part of the test?Go to Step 4Go to Step 8
4Test the low reference circuit between the PCM and the MAP sensor for an intermittent open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 8Go to Step 5
5IMPORTANT: Disconnecting the PCM may eliminate the short during the testing. Test the MAP sensor signal circuit between the PCM and the MAP sensor for an intermittent short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.Did you find and correct the condition?Go to Step 8Go to Step 6
6Test for an intermittent and for a poor connection at the MAP sensor. Refer to Testing for Continuity and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 8Go to Step 7
7Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Continuity and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 8
8Clear 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 9
9Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) ListSystem OK
IMPORTANT
Disconnecting the PCM may eliminate the short during the testing.

DTC P1106 - MAP Sensor Circuit Intermittent High Voltage

The manifold absolute pressure (MAP) sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The MAP sensor has the following circuits

  1. 5-volt reference circuit
  2. Low reference circuit
  3. MAP sensor signal circuit

The powertrain control module (PCM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The PCM also provides a ground on the low reference circuit. The MAP sensor provides a signal to the PCM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The PCM should detect a low signal voltage at a low MAP, such as during an idle or a deceleration. The PCM should detect a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at a wide open throttle (WOT). The MAP sensor is also used in order to determine the barometric pressure (BARO). This occurs when the ignition switch is turned ON, with the engine OFF. The BARO reading may also be updated whenever the engine is operated at WOT. The PCM monitors the MAP sensor signal for voltage outside of the normal range.

If the PCM detects a MAP sensor signal voltage that is intermittently low, DTC P1107 sets.

  1. DTCs P0121, P0122, or P0123 are not set.
  2. The ignition is ON.
  3. The throttle angle is more than 0 percent when the engine speed is less than 1,000 RPM. Or
  4. The throttle angle is more than 10 percent when the engine speed is more than 1,000 RPM.

The PCM detects that the MAP sensor voltage is intermittently less than 0.1 volt.

  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.

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

  1. 3: Many intermittent open or shorted circuits come and go with harness/connector movement caused by vibration, by engine torque, and by bumps. This step attempts to recreate this condition.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Start the engine. Monitor the diagnostic trouble code (DTC) information with the scan tool. Does the scan tool display DTC P0107 or P0641 set?Go to Diagnostic Trouble Code (DTC) ListGo to Step 3
3Turn OFF the ignition. Turn ON the ignition, with the engine OFF. Observe the MAP sensor parameter with the scan tool. Attempt to induce the fault that set the DTC by manipulating the following items: The MAP sensor wiring harness The MAP sensor connector The PCM connector Refer to Inducing Intermittent Fault Conditions in Wiring Systems and Intermittent Conditions .Is the MAP sensor voltage affected during any part of the test?Go to Step 4Go to Step 8
4Test the 5-volt reference circuit between the PCM and the MAP sensor for an intermittent open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 8Go to Step 5
5Test the MAP sensor signal circuit between the PCM and the MAP sensor for the following conditions: A short to ground An open High resistance Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 8Go to Step 6
6Test for an intermittent and for a poor connection at the MAP sensor. Refer to Testing for Continuity and Connector Repairs in Wiring Systems. Did you find and correct the condition?5 VGo to Step 8Go to Step 7
7Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Continuity and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 8
8Clear 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 9
9Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) ListSystem OK

DTC P1107 - MAP Sensor Circuit Intermittent Low Voltage

The intake air temperature (IAT) sensor is a variable resistor. The IAT sensor has a signal circuit and a low reference circuit. The IAT sensor measures the temperature of the air entering the engine. The powertrain control module (PCM) supplies 5 volts to the IAT signal circuit and a ground for the IAT low reference circuit. When the IAT sensor is cold, the sensor resistance is high. When the air temperature increases, the sensor resistance decreases. With high sensor resistance, the PCM detects a high voltage on the IAT signal circuit. With lower sensor resistance, the PCM detects a lower voltage on the IAT signal circuit. If the PCM detects an intermittent high IAT signal voltage, indicating a low temperature, DTC P1111 sets.

  1. DTCs P0101, P0102, P0103, P0116, P0117, P0118, P0502, P0503 are not set.
  2. The vehicle speed sensor (VSS) is less than 56 km/h (35 mph).
  3. The mass air flow (MAF) is less than 12 g/s.
  4. The engine coolant temperature (ECT) is more than 60°C (140°F).
  5. The engine run time is more than 180 seconds.

The PCM detects that the intake air temperature (IAT) is less than -38°C (-36°F) intermittently for more than 3 seconds.

  1. The control module stores the DTC information into memory when the diagnostic runs and fails.
  2. The malfunction indicator lamp (MIL) will not illuminate.
  3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
  4. The driver information center, if equipped, may display a message.
  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 Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Observe the DTC Information with a scan tool. Is DTC P0113 set?Go to DTC P0113Go to Step 3
3Test for an intermittent and for a poor connection at the IAT sensor. 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 8Go to Step 4
4Test the IAT signal circuit between the IAT sensor and the PCM for an intermittent open. Refer to Inducing Intermittent Fault Conditions , Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 8Go to Step 5
5Test the IAT signal circuit between the IAT sensor and the PCM for an intermittent short to voltage. Refer to Inducing Intermittent Fault Conditions , Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 8Go to Step 6
6Test the low reference circuit for an intermittent open. Refer to Inducing Intermittent Fault Conditions , Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 8Go to Step 7
7Test for an intermittent and for a poor connection at the PCM. 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 8Go to Intermittent Conditions
8Clear 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 9
9Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) ListSystem OK

DTC P1111

The intake air temperature (IAT) sensor is a variable resistor. The IAT sensor has a signal circuit and a low reference circuit. The IAT sensor measures the temperature of the air entering the engine. The powertrain control module (PCM) supplies 5 volts to the IAT signal circuit and a ground for the IAT low reference circuit. When the IAT sensor is cold, the sensor resistance is high. When the air temperature increases, the sensor resistance decreases. With high sensor resistance, the PCM detects a high voltage on the IAT signal circuit. With lower sensor resistance, the PCM detects a lower voltage on the IAT signal circuit. If the PCM detects an intermittent low IAT signal voltage, indicating a high temperature, DTC P1112 sets.

  1. DTCs P0101, P0102, P0103, P0116, P0117, P0118, P0502, P0503 are not set.
  2. The engine run time is more than 10 seconds.
  3. The vehicle speed sensor (VSS) indicates that vehicle speed is more than 40 km/h (25 mph).

The PCM detects that the intake air temperature (IAT) is more than 123°C (253°F) intermittently for more than 20 seconds.

  1. The control module stores the DTC information into memory when the diagnostic runs and fails.
  2. The malfunction indicator lamp (MIL) will not illuminate.
  3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
  4. The driver information center, if equipped, may display a message.
  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 Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Observe the DTC Information with a scan tool. Is DTC P0112 set?Go to DTC P0112Go to Step 3
3Test for an intermittent and for a poor connection at the IAT sensor. 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 5Go to Step 4
4Test the IAT signal circuit between the IAT sensor and the PCM for an intermittent short to ground. Refer to Inducing Intermittent Fault Conditions , Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 5Go to Intermittent Conditions
5Clear 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 6
6Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) ListSystem OK

DTC P1112

The engine coolant temperature (ECT) sensor is a variable resistor, that measures the temperature of the engine coolant. The powertrain control module (PCM) supplies 5 volts to the ECT signal circuit and a ground for the ECT low reference circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance decreases. With high sensor resistance, the PCM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the PCM detects a lower voltage on the ECT signal circuit. If the PCM detects an excessively low ECT signal voltage, which is a high temperature indication, DTC P1114 sets.

The engine run time is more than 5 seconds.

The PCM detects that the ECT sensor parameter is more than 139°C (282°F) intermittently for more than 5 seconds.

  1. The control module stores the DTC information into memory when the diagnostic runs and fails.
  2. The malfunction indicator lamp (MIL) will not illuminate.
  3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
  4. The driver information center, if equipped, may display a message.
  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 Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Observe the DTC information with a scan tool. Is DTC P0117 set?Go to DTC P0117Go to Step 3
3Observe the Engine Coolant Temperature parameter with a scan tool while moving the ECT sensor connector and the Powertrain Control Module connector. Refer to Inducing Intermittent Fault Conditions in Wiring Systems. Does the scan tool indicate an abrupt change in value?Go to Step 5Go to Step 4
4Observe the ECT parameter with a scan tool while moving the wiring harness at the ECT sensor and the PCM. Refer to Inducing Intermittent Fault Conditions in Wiring Systems. Does the scan tool indicate an abrupt change in value?Go to Step 6Go to Step 7
5Repair the connector/terminal as necessary. Refer to Connector Repairs in Wiring Systems. Did you complete the repair?Go to Step 7
6Repair the harness/wiring as necessary. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 7
7Clear 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 8
8Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) ListSystem OK

DTC P1114

The engine coolant temperature (ECT) sensor is a variable resistor, that measures the temperature of the engine coolant. The powertrain control module (PCM) supplies 5 volts to the ECT signal circuit and a ground for the ECT low reference circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance decreases. With high sensor resistance, the PCM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the PCM detects a lower voltage on the ECT signal circuit. If the PCM detects an excessively high signal voltage, which is a low temperature indication, DTC P1115 sets.

The engine run time is more than 5 seconds.

The PCM detects that the ECT sensor parameter is less than -38°C (-36°F) intermittently for more than 5 seconds.

  1. The control module stores the DTC information into memory when the diagnostic runs and fails.
  2. The malfunction indicator lamp (MIL) will not illuminate.
  3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
  4. The driver information center, if equipped, may display a message.
  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 Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Observe the DTC information with a scan tool. Is DTC P0118 set?Go to DTC P0118Go to Step 3
3Observe the Engine Coolant Temperature sensor parameter with a scan tool while moving the ECT sensor connector and the Powertrain Control Module connector. Refer to Inducing Intermittent Fault Conditions in Wiring Systems. Does the scan tool indicate an abrupt change in value?Go to Step 5Go to Step 4
4Observe the ECT parameter with a scan tool while moving the wiring harness at the ECT sensor and the PCM. Refer to Inducing Intermittent Fault Conditions in Wiring Systems. Does the scan tool indicate an abrupt change in value?Go to Step 6Go to Step 7
5Repair the connector/terminal as necessary. Refer to Connector Repairs in Wiring Systems. Did you complete the repair?Go to Step 7
6Repair the harness/wiring as necessary. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 7
7Clear 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 8
8Observe the Capture Info with a scan tool. Does the scan tool display any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) ListSystem OK

DTC P1115

The throttle position (TP) sensor is used by the powertrain control module (PCM) to determine the throttle plate angle for various engine management systems. The TP sensor is a potentiometer type sensor with three circuits

  1. A 5-volt reference circuit
  2. A low reference circuit
  3. A TP sensor signal circuit

The PCM provides the TP sensor with 5 volts on the 5-volt reference circuit and a ground on the low reference circuit. Rotation of the TP sensor rotor from the closed throttle position to the wide open throttle (WOT) position provides the PCM with a signal voltage from below 1 volt to greater than 4 volts through the TP sensor signal circuit. If the PCM detects an intermittent excessively high signal voltage, DTC P1121 sets.

The ignition is ON.

The PCM detects that the TP sensor voltage is intermittently more than 4.9 volts.

  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.

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

  1. 7: This test will determine an intermittent faulty TP sensor utilizing the DMMs MIN MAX, 100 millisecond capture mode.
StepActionYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Turn OFF the ignition. Disconnect the throttle position (TP) sensor electrical connector. Turn ON the ignition, with the engine OFF. Measure the voltage from the 5-volt reference circuit of the TP sensor to a good ground with a DMM. Lightly touch and move the related engine wiring harnesses and connectors for all 5-volt reference circuits while observing voltage. Any change in voltage indicates the area where a short to voltage may be found. Refer to Testing for Electrical Intermittents and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 9Go to Step 3
3Measure the voltage from the signal circuit of the TP sensor to a good ground with a DMM. Lightly touch and move the related engine wiring harnesses and connectors while observing voltage. Any change in voltage indicates the area where a short to voltage may be found. Refer to Testing for Electrical Intermittents and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 9Go to Step 4
4Measure the resistance from the low reference circuit of the TP sensor to a good ground with a DMM. Lightly touch and move the related engine wiring harnesses and connectors while observing resistance. Any change in resistance indicates the area where an open or high resistance may be found. Refer to Testing for Electrical Intermittents , Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 9Go to Step 5
5Test for poor connections at the TP sensor harness 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 9Go to Step 6
6Test for poor connections at the powertrain control module (PCM) harness 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 9Go to Step 7
7Turn OFF the ignition. Measure the resistance between the TP sensor signal terminal and the low reference terminal at the TP sensor using the MIN MAX function on the DMM. Slowly press the accelerator pedal to the wide open throttle (WOT) position, then release the pedal back to the closed throttle position several times. Did you observe a MAX value of infinite ohms or a MIN value of 0 ohms?Go to Step 8Go to Intermittent Conditions
8Replace the TP sensor. Refer to Throttle Position (TP) Sensor Replacement . Did you complete the replacement?Go to Step 9
9Clear 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 10
10Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) ListSystem OK

DTC P1121

The throttle position (TP) sensor is used by the powertrain control module (PCM) to determine the throttle plate angle for various engine management systems. The TP sensor is a potentiometer type sensor with three circuits

  1. A 5-volt reference circuit
  2. A low reference circuit
  3. A TP sensor signal circuit

The PCM provides the TP sensor with 5 volts on the 5-volt reference circuit and a ground on the low reference circuit. Rotation of the TP sensor rotor from the closed throttle position to the wide open throttle (WOT) position provides the PCM with a signal voltage from below 1 volt to greater than 4 volts through the TP sensor signal circuit. If the PCM detects an intermittent excessively low signal voltage, DTC P1122 sets.

The ignition is ON.

The PCM detects that the TP sensor voltage is intermittently less than 0.1 volt.

  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.

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

  1. 6: This test will determine an intermittent faulty TP sensor utilizing the DMMs MIN MAX, 100 millisecond capture mode.
StepActionYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Turn OFF the ignition. Disconnect the throttle position (TP) sensor harness connector. Measure the voltage from the 5-volt reference circuit of the TP sensor to a good ground, with a DMM. Turn ON the ignition. Lightly touch and move the related engine wiring harnesses and connectors for all 5-volt reference circuits while observing the DMM. Any change in voltage indicates the area where an open, or a short to ground in the 5-volt reference circuit may be found. Refer to Testing for Electrical Intermittents , Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 8Go to Step 3
3Connect the TP sensor. Install a scan tool and observe the TP sensor voltage parameter. Lightly touch and move the related engine wiring harnesses and connectors for the TP sensor signal circuit while observing voltage. Any change in voltage indicates the area where an open or a short to ground in the TP sensor signal circuit may be found. Refer to Testing for Electrical Intermittents and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 8Go to Step 4
4Test for poor connections at the TP sensor harness 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 8Go to Step 5
5Test for poor connections at the harness connector of the powertrain control module (PCM). 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 8Go to Step 6
6Turn OFF the ignition. Measure the resistance between the TP sensor signal terminal and the 5-volt reference terminal at the TP sensor using the MIN MAX function on the DMM. Slowly depress the accelerator pedal to the wide open throttle (WOT) position, then release the pedal back to the closed throttle position several times. Did you observe a MAX value of infinite ohms or a MIN value of 0 ohms?Go to Step 7Go to Intermittent Conditions
7Replace the TP sensor. Refer to Throttle Position (TP) Sensor Replacement . Did you complete the replacement?Go to Step 8
8Clear 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 9
9Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) ListSystem OK

DTC P1122

Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the vehicle is first started, the powertrain control module (PCM) operates in an Open Loop mode, ignoring the HO2S signal voltage when calculating the air-to-fuel ratio. The PCM supplies the HO2S with a reference, or bias, voltage of about 450 mV. The HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage once in Closed Loop. A high HO2S voltage output indicates a rich fuel mixture. A low HO2S voltage output indicates a lean mixture. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature, and to provide an accurate voltage signal. If the PCM detects that the HO2S 1 voltage did not switch above 598 mV and below 299 mV enough times during a calibrated time period, DTC P1133 will set.

The HO2S 1 has the following circuits

  1. A HO2S 1 high signal circuit
  2. A HO2S 1 low reference circuit
  3. A HO2S 1 heater ignition voltage circuit
  4. A HO2S 1 heater low control circuit
  5. A low reference loop circuit
  1. DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0201-P0206, P0401, P0442, P0443, P0446, P0449, P0455, P0496 are not set.
  2. The vehicle is not in Park or Neutral.
  3. The Engine Run Time parameter is at least 60 seconds.
  4. The Loop Status parameter is closed.
  5. The MAF Sensor parameter is between 13-29 g/s.
  6. The TP Sensor parameter is more than 2 percent.
  7. The Engine Speed parameter is between 1,300-3,000 RPM.
  8. The ECT Sensor parameter is more than 65°C (149°F).
  9. The system voltage is between 9-18 volts.
  10. The above conditions have been met for 1.5 seconds.

The PCM detects an insufficient number of switches during a 90 second monitoring period.

  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 Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Start the engine. Allow the engine to idle at operating temperature. Refer to Scan Tool Data List . Clear the DTC and record the Freeze/Frame Failure Records. Observe the heated oxygen sensor (HO2S) 1 voltage parameter with a scan tool. Does the HO2S 1 voltage fluctuate rapidly above and below the specified range?350-550 mVGo to Step 3Go to Step 4
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?Go to Step 4Go to Intermittent Conditions
4Turn OFF the ignition. Disconnect the heated oxygen sensor (HO2S) 1 connector. Turn ON the ignition, with the engine OFF. Measure the voltage from the HO2S high signal circuit, on the engine harness side, to a good ground with a DMM. Is the HO2S 1 voltage parameter within the specified range?425-500 mVGo to Step 5Go to Step 6
5Turn OFF the ignition. Connect a 3-amp fused jumper wire between the HO2S 1 high signal circuit and the HO2S 1 low reference circuit, on the engine harness side. Turn ON the ignition, with the engine OFF. Observe the HO2S 1 voltage parameter with a scan tool. Is the HO2S 1 voltage less than the specified value?25 mVGo to Step 7Go to Step 6
6Turn OFF the ignition. Disconnect both powertrain control module (PCM) connectors. Measure the resistance of each of the following circuits with a DMM: HO2S 1 high signal circuit between HO2S connector and the PCM connector HO2S 1 low reference circuit between HO2S connector and the PCM connector Low reference loop between pin C1-29 and pin C2-80 of the PCM connectors-Refer to Circuit Testing in Wiring Systems. Is the resistance of each circuit less than the specified value?5 ohmGo to Step 10Go to Step 11
7Remove the jumper wire from the previous step. Connect a test lamp between the HO2S heater ignition voltage circuit and the HO2S heater low control circuit on the engine harness side. Start the engine. Does the test lamp illuminate?Go to Step 8Go to Step 4 of DTC P0135
8Inspect for the following that may affect the HO2S operation: NOTE: Refer to Silicon Contamination of Heated Oxygen Sensors Notice in Cautions and Notices. HO2S for contamination NOTE: Refer to Heated Oxygen and Oxygen Sensor Notice in Cautions and Notices. Chafed, burnt, cut, pinched, or otherwise damaged HO2S wiring The HO2S must have a clean air reference in order to function properly. This clean air reference is obtained by way of the HO2S wires. Obstruction of the air reference and degraded HO2S performance could result from any attempt to repair the above conditions. Exhaust system leaks or restrictions Evaporative Emissions (EVAP) System malfunction-Inspect the EVAP control system. Refer to Inspection/Maintenance (I/M) Evaporative Emission (EVAP) System Set Procedure . The fuel pressure-Incorrect fuel pressure can affect HO2S operation. Refer to Fuel System Diagnosis . Did you find and correct the condition?Go to Step 14Go to Step 9
9Test for an intermittent and for a poor connection at the harness connector of the HO2S 1. Refer to Testing for Intermittent Conditions and Poor Connections , Connector Repairs , and Heated Oxygen Sensor (HO2S) Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 12
10Test for an intermittent and for a poor connection at the harness connector of the PCM. 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 14Go to Step 13
11Repair the circuit that measured a high resistance or an open. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 14
12Replace the HO2S 1 sensor. Refer to Heated Oxygen Sensor Replacement - Position 1 . Did you complete the replacement?Go to Step 14
13Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . 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) ListSystem OK
NOTE
Refer to Silicon Contamination of Heated Oxygen Sensors Notice in Cautions and Notices.
NOTE
Refer to Heated Oxygen and Oxygen Sensor Notice in Cautions and Notices.

DTC P1133

Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the vehicle is first started, the powertrain control module (PCM) operates in an Open Loop mode, ignoring the HO2S signal voltage when calculating the air-to-fuel ratio. The PCM supplies the HO2S with a reference, or bias, voltage of about 450 mV. The HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage once in Closed Loop. A high HO2S voltage output indicates a rich fuel mixture. A low HO2S voltage output indicates a lean mixture. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature, and to provide an accurate voltage signal. The PCM calculates a transition time difference for rich-to-lean and lean-to-rich HO2S voltage switches. If the PCM detects that the calculated transition time difference is incorrect, DTC P1134 will set.

The HO2S 1 has the following circuits

  1. HO2S 1 high signal
  2. HO2S 1 low reference
  3. HO2S 1 heater ignition voltage
  4. HO2S 1 heater low control
  5. Low reference loop
  1. DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0201-P0206, P0401, P0442, P0443, P0446, P0449, P0455, P0496 are not set.
  2. The vehicle is not in Park or Neutral.
  3. The Engine Run Time parameter is at least 60 seconds.
  4. The Loop Status parameter is closed.
  5. The TP Sensor parameter is more than 2 percent.
  6. The MAF Sensor parameter is between 15-29 g/s.
  7. The Engine Speed parameter is between 1,300-3,000 RPM.
  8. The ECT Sensor parameter is more than 65°C (149°F).
  9. The system voltage is between 9-18 volts.
  10. The above conditions have been met for 1.5 seconds.

The PCM detects that the average transition time difference exceeds a predetermined amount during a 90 second monitoring period.

  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 Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Start the engine. Allow the engine to idle at operating temperature. Refer to Scan Tool Data List . Clear the DTC and record the Freeze/Frame Failure Records. Observe the heated oxygen sensor (HO2S) 1 voltage parameter with a scan tool. Does the HO2S 1 voltage fluctuate rapidly above and below the specified range?350-550 mVGo to Step 3Go to Step 4
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?Go to Step 4Go to Intermittent Conditions
4Turn OFF the ignition. Disconnect the heated oxygen sensor (HO2S) 1 connector. Turn ON the ignition, with the engine OFF. Measure the voltage from the HO2S 1 high signal circuit, on the engine harness side, to a good ground with a DMM. Is the HO2S 1 voltage within the specified range?425-500 mVGo to Step 5Go to Step 6
5Turn OFF the ignition. Connect a 3-amp fused jumper wire between the HO2S 1 high signal circuit and the HO2S 1 low reference circuit on the engine harness side. Turn ON the ignition, with the engine OFF. Observe the HO2S 1 voltage parameter with a scan tool. Is the HO2S 1 voltage less than the specified value?25 mVGo to Step 7Go to Step 6
6Turn OFF the ignition. Disconnect both powertrain control module (PCM) connectors. Measure the resistance of each of the following circuits with a DMM: HO2S 1 high signal circuit between HO2S connector and the PCM connector HO2S 1 low reference circuit between HO2S connector and the PCM connector Low reference loop between pin C1-29 and pin C2-80 of the PCM connectors-Refer to Circuit Testing in Wiring Systems. Is the resistance of each circuit less than the specified value?5 ohmGo to Step 10Go to Step 11
7Remove the jumper wire from the previous step. Connect a test lamp between the HO2S heater ignition voltage circuit, and HO2S heater low control circuit terminals on the engine harness side. Start the engine. Does the test lamp illuminate?Go to Step 8Go to Step 4 of DTC P0135
8Inspect for the following that may affect the HO2S operation: NOTE: Refer to Silicon Contamination of Heated Oxygen Sensors Notice in Cautions and Notices. HO2S for contamination NOTE: Refer to Heated Oxygen and Oxygen Sensor Notice in Cautions and Notices. Chafed, burnt, cut, pinched, or otherwise damaged HO2S wiring The HO2S must have a clean air reference in order to function properly. This clean air reference is obtained by way of the HO2S wires. Obstruction of the air reference and degraded HO2S performance could result from any attempt to repair the above conditions. Exhaust system leaks or restrictions Evaporative Emissions (EVAP) System malfunction-Inspect the EVAP control system. Refer to Inspection/Maintenance (I/M) Evaporative Emission (EVAP) System Set Procedure . The fuel pressure-Incorrect fuel pressure can affect HO2S operation. Refer to Fuel System Diagnosis . Did you find and correct the condition?Go to Step 14Go to Step 9
9Test for an intermittent and for a poor connection at the harness connector of the HO2S 1. Refer to Testing for Intermittent Conditions and Poor Connections , Connector Repairs , and Heated Oxygen Sensor (HO2S) Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 12
10Test for an intermittent and for a poor connection at the harness connector of the PCM. 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 14Go to Step 13
11Repair the circuit that measured a high resistance or an open. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 14
12Replace the HO2S 1 sensor. Refer to Heated Oxygen Sensor Replacement - Position 1 . Did you complete the replacement?Go to Step 14
13Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . 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) ListSystem OK
NOTE
Refer to Silicon Contamination of Heated Oxygen Sensors Notice in Cautions and Notices.
NOTE
Refer to Heated Oxygen and Oxygen Sensor Notice in Cautions and Notices.

DTC P1134

The ignition control module (ICM) has independent power and ground circuits. The circuits between the ICM and the powertrain control module (PCM) consists of the following circuits

  1. The ignition control (IC) timing signal circuit
  2. The IC timing control circuit
  3. The low resolution engine speed signal circuit
  4. The low reference signal circuit

The ICM sends 3X signals to the PCM and controls the timing advance during engine cranking. The timing advance changes to PCM control after the following actions occur

  1. The PCM receives the second 3X signal
  2. The PCM applies 5 volts to the IC timing signal circuit.
  3. The timing advance switches to PCM control.

If the PCM detects an open in the IC timing control circuit, DTC P1351 sets.

The engine is running.

  1. The PCM detects an open in the IC timing control circuit.
  2. The condition is present for 300 3X reference periods, 100 crankshaft revolutions.
  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 Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
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
3Disconnect the powertrain control module (PCM). Turn ON the ignition, with the engine OFF. Measure the resistance from the ignition control (IC) timing control circuit of the ignition control module (ICM) to the low reference circuit of the ICM with a DMM. Is the resistance within the specified range?100-600 ohmGo to Step 6Go to Step 4
4Turn OFF the ignition. Leave the PCM disconnected. Disconnect the ICM. Test the IC timing control circuit for an open. Refer to Circuit Testing in Wiring Systems. Did you find and correct the condition?Go to Step 9Go to Step 5
5Test for an intermittent and for a poor connection at the ICM. 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 9Go to Step 7
6Test for an intermittent and for a poor connection at the PCM. 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 9Go to Step 8
7Replace the ICM. Refer to Ignition Control Module Replacement . Did you complete the replacement?Go to Step 9
8Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . Did you complete the replacement?Go to Step 9
9Clear the DTCs with a scan tool. Turn OFF 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 10
10Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) ListSystem OK

DTC P1351

The ignition control module (ICM) has independent power and ground circuits. The circuits between the ICM and the powertrain control module (PCM) consists of the following circuits

  1. The ignition control (IC) timing signal circuit
  2. The IC timing control circuit
  3. The low resolution engine speed signal circuit
  4. The low reference signal

The ICM sends 3X signals to the PCM and controls the timing advance during engine cranking. The timing advance changes to PCM control after the following actions occur

  1. The PCM receives the second 3X signal.
  2. The PCM applies 5 volts to the IC timing signal circuit.
  3. The timing advance switches to PCM control.

If the PCM detects an open in the IC timing signal circuit, DTC P1352 sets.

The engine is running.

  1. The PCM detects an open circuit in the IC timing signal circuit.
  2. The condition is present for 300 3X reference periods, 100 crankshaft revolutions.
  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 Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
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 powertrain control module (PCM). Measure the resistance between the ignition control (IC) timing control and low reference circuits of the ignition control module (ICM). Turn On the ignition, with the engine OFF. Probe the IC timing signal circuit with a test lamp that is connected to battery voltage. Is the resistance within the specified range?6,000-10,000 ohmGo to Step 6Go to Step 4
4Turn OFF the ignition. Leave the PCM disconnected. Disconnect the ICM. Test the IC timing signal circuit of the ICM for an open. Refer to Circuit Testing in Wiring Systems. Did you find and correct the condition?Go to Step 9Go to Step 5
5Test for an intermittent and for a poor connection at the ICM. 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 9Go to Step 7
6Test for an intermittent and for a poor connection at the PCM. 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 9Go to Step 8
7Replace the ICM. Refer to Ignition Control Module Replacement . Did you complete the replacement?Go to Step 9
8Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . Did you complete the replacement?Go to Step 9
9Clear the DTCs with a scan tool. Turn OFF 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 10Go to Step 2
10Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) ListSystem OK

DTC P1352

The ignition control module (ICM) has independent power and ground circuits. The circuits between the ICM and the powertrain control module (PCM) consist of the following circuits

  1. The ignition control (IC) timing signal circuit
  2. The IC timing control circuit
  3. The low-resolution engine speed signal circuit
  4. A low reference signal circuit

The ICM sends 3X signals to the PCM. The ICM controls the timing advance during engine cranking. The timing advance changes to PCM control after the following actions

  1. The PCM receives the second 3X signal.
  2. The PCM applies 5 volts to the IC timing signal circuit.
  3. The timing advance switches to PCM control.
  4. If the PCM does not monitor IC pulses while IC mode spark advance is commanded DTC P1361 sets.

The engine is running.

  1. The PCM does not monitor IC pulses while IC mode spark advance is commanded.
  2. The condition is present for 300 3X reference periods, 100 crankshaft revolutions.
  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 Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
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 P1362 also set?Go to Step 6Go to Step 4
4Turn OFF the ignition. Disconnect the powertrain control module (PCM). Turn ON the ignition, with the engine OFF. Probe the ignition control (IC) timing control circuit of the ignition control module (ICM) with a test lamp connected to a good ground. Does the test lamp illuminate?Go to Step 5Go to Step 16
5Turn OFF the ignition. Leave the PCM disconnected. Disconnect the ICM. Turn ON the ignition, with the engine OFF. Probe the IC timing control circuit of the ICM with a test lamp connected to ground. Does the test lamp illuminate?Go to Step 12Go to Step 10
6Turn OFF the ignition. Disconnect the ICM. Probe the IC timing control circuit at the PCM with a test lamp connected to battery voltage. Does the test lamp illuminate?Go to Step 13Go to Step 7
7Leave the ignition OFF. Leave the ICM disconnected. Probe the IC timing signal circuit of the ICM with a test lamp connected to battery voltage. Does the test lamp illuminate?Go to Step 14Go to Step 8
8Leave the ignition OFF. Leave the PCM disconnected. Leave the ICM disconnected. Test for a short between the IC timing control and IC timing signal circuits. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 17Go to Step 9
9Leave the ignition OFF. Reconnect the ICM. Leave the PCM disconnected. Turn ON the ignition, with the engine OFF. Measure the resistance between the IC timing control circuit of the ICM and a good ground. Observe the DMM while probing the IC timing signal circuit of the ICM with a test lamp connected to battery positive voltage. Does the resistance switch between the two indicated ranges?100-600 ohm to 6,000-10,000 ohmGo to Step 11Go to Step 10
10Test for shorted terminals or for poor connections at the ICM. 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 17Go to Step 15
11Test for shorted terminals or for poor connections at the PCM. 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 17Go to Step 16
12Repair the short to voltage in the IC timing control circuit of the ICM. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 17
13Repair the short to ground or the low reference in the IC timing control circuit of the ICM. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 17
14Repair the short to ground or the low reference in the IC timing signal circuit of the ICM. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 17
15Replace the ICM. Refer to Ignition Control Module Replacement . Did you complete the replacement?Go to Step 17
16Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . 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. Does the DTC run and pass?Go to Step 18Go to Step 2
18Observe the capture info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) ListSystem OK

DTC P1361

The ignition control module (ICM) has independent power and ground circuits. The circuits between the ICM and the powertrain control module (PCM) consist of the following circuits

  1. The ignition control (IC) timing signal circuit
  2. The IC timing control circuit
  3. The low-resolution engine speed signal circuit
  4. A low reference signal circuit

The ICM sends 3X signals to the PCM. The ICM controls the timing advance during engine cranking. The timing advance changes to PCM control after the following actions

  1. The PCM receives the second 3X signal.
  2. The PCM applies 5 volts to the IC timing signal circuit.
  3. The timing advance switches to PCM control.
  4. If the PCM detects a short to voltage in the IC timing signal circuit DTC P1362 sets.

The engine is running.

  1. The PCM detects a short to voltage in the IC timing signal circuit.
  2. The condition is present for 300 3X reference periods, 100 crankshaft revolutions.
  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 Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
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 P1361 also set?Go to Step 6Go to Step 4
4Turn OFF the ignition. Disconnect the powertrain control module (PCM). Turn ON the ignition, with the engine OFF. Probe the ignition control (IC) timing signal circuit of the ignition control module (ICM) with a test lamp connected to a good ground. Does the test lamp illuminate?Go to Step 5Go to Step 11
5Turn OFF the ignition. Leave the PCM disconnected. Disconnect the ICM connector. Turn ON the ignition, with the engine OFF. Probe the IC timing signal circuit of the ICM with a test lamp connected to a good ground. Does the test lamp illuminate?Go to Step 12Go to Step 10
6Turn OFF the ignition. Disconnect the PCM. Disconnect the ICM. Probe the IC timing control circuit of the ICM with a test lamp connected to battery voltage. Does the test lamp illuminate?Go to Step 13Go to Step 7
7Leave the ignition OFF. Leave the PCM disconnected. Leave the ICM disconnected. Probe the IC timing signal circuit of the ICM with a test lamp connected to a good ground. Does the test lamp illuminate?Go to Step 14Go to Step 8
8Leave the ignition OFF. Leave the PCM disconnected. Leave the ICM disconnected. Test for a short between the IC timing control and IC timing signal circuits. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 17Go to Step 9
9Leave the ignition OFF. Reconnect the ICM. Leave the PCM disconnected. Turn ON the ignition, with the engine OFF. Measure the resistance between the IC timing control circuit of the ICM and a good ground. Observe the DMM while probing the IC timing signal circuit of the ICM with a test lamp connected to battery positive voltage. Does the resistance switch between the two indicated ranges?100-600 ohm to 6,000-10,000 ohmGo to Step 11Go to Step 10
10Test for shorted terminals or for a poor connection at the ICM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the conditions?Go to Step 17Go to Step 15
11Test for shorted terminals or for a poor connection at the PCM. 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 17Go to Step 16
12Repair the short to voltage in the IC timing signal circuit of the ICM. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 17
13Repair the short to ground in the IC timing control circuit of the ICM. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 17
14Repair the short to ground in the IC timing signal circuit of the ICM. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 17
15Replace the ICM. Refer to Ignition Control Module Replacement . Did you complete the replacement?Go to Step 17
16Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . 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) ListSystem OK

DTC P1362

A 3X reference signal is produced by the ignition control (IC) module. The IC module calculates the 3X reference signal by dividing the crankshaft position (CKP) sensor 7X pulses by 2 when the engine is running and the CKP synchronizing pulses are being received. The powertrain control module (PCM) uses the 3X reference signal to calculate the engine RPM and the CKP at engine speeds above 1,600 RPM. The PCM also uses these pulses to initiate injector pulses. The PCM compares the 3X reference pulses to the 24X CKP pulses and the camshaft position (CMP) pulses. The engine will continue to start and run using only the 24X CKP and CMP sensor signals. If the PCM detects an incorrect number of pulses on the low resolution engine speed signal circuit, DTC P1374 sets.

The engine is running, and the 24X reference pulses are being received.

  1. The ratio of 24X reference pulses to 3X reference pulses received by the PCM does not equal 8.
  2. The ratio of 24X reference pulses to CMP PCM input pulses received by the PCM equals 48.
  3. The conditions are present for more than 10 seconds.
  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.

DTC P1374 can be caused by secondary components leaking high voltage into the IC module.

Inspect for the following conditions

  1. Incorrect harness routing near secondary ignition components
  2. Ignition coil arcing to wiring harness or IC module-Inspect the ignition coils for the following conditions: Cracks Carbon tracking Other signs of damage
  3. Secondary ignition wires arcing to the wiring harness
  4. If the DTC is determined to be intermittent, refer to «Intermittent Conditions»(/buick/rendezvous/i-2001-2007/remont/testing-diagnostics/#engine-controls-34l-troubleshooting__intermittent-conditions) .
StepActionYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Attempt to start the engine. Does the engine start and run?Go 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. Does the DTC fail this ignition?Go to Step 4Go to Diagnostic Aids
4Turn OFF the ignition. Disconnect the 6-way ignition control module connector. Remove the injector fuse. Turn ON the ignition, with the engine OFF. Momentarily probe the low resolution engine speed signal circuit at the ignition module harness connector with a test lamp connected to B+. Observe the Engine Speed parameter with a scan tool. Is an Engine Speed displayed?Go to Step 8Go to Step 5
5Did the test lamp illuminate?Go to Step 7Go to Step 6
6Turn OFF the ignition. Disconnect the PCM. Turn ON the ignition, with the engine OFF. Test the low resolution engine speed signal circuit of the ignition control module for the following conditions: An open A short to voltage High resistance Refer to Wiring Repairs and Circuit Testing in Wiring Systems.Did you find and correct the condition?Go to Step 12Go to Step 9
7Turn OFF the ignition. Disconnect the PCM. Test the low resolution engine speed signal circuit of the ignition control module for a short to ground or high resistance. Refer to Wiring Repairs and Circuit Testing in Wiring Systems. Did you find and correct the condition?Go to Step 12Go to Step 9
8Test for an intermittent and for a poor connection at the ignition control module. 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 12Go to Step 10
9Test for an intermittent and for a poor connection at the PCM. 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 12Go to Step 11
10Replace the ignition control module. Refer to Ignition Control Module Replacement . Did you complete the replacement?Go to Step 12
11Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . 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) ListSystem OK

DTC P1374

System Description

The powertrain control module (PCM) detects engine misfire events by monitoring variations in the crankshaft rotation speed. Wheel speed changes caused by rough road conditions can cause changes in crankshaft speed. By monitoring the wheel speed sensors, the anti-lock brake system (ABS) can determine if the vehicle is operating on a rough road. If the ABS is detecting a rough road condition severe enough to effect misfire detection, a rough road signal is sent to the PCM on the serial data circuit. If DTC P0300 is set and the rough road information is not available due to an ABS malfunction, DTC P1380 will set.

  1. The vehicle speed is more than 16 km/h (10 mph).
  2. The engine load is less than 87 percent.
  3. The engine misfire is detected-DTC P0300 set.
  4. The engine speed is less than 5,000 RPM.

An ABS malfunction exists preventing the PCM from receiving rough road detection data.

  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
1Did you perform the Diagnostic System Check-Engine Controls?Go to Diagnostic System Check - ABS in Antilock Brake SystemGo to Diagnostic System Check - Engine Controls

DTC P1380

The powertrain control module (PCM) detects engine misfire events by monitoring variations in the crankshaft rotation speed. Wheel speed changes caused by rough road conditions can cause changes in crankshaft rotation speed. By monitoring the wheel speed sensors, the anti-lock brake system (ABS) can determine if the vehicle is operating on a rough road. If the ABS is detecting a rough road condition severe enough to effect misfire detection, a rough road signal is sent to the PCM on the serial data circuit. If DTC P0300 is set and the rough road information is not available due to an ABS malfunction, DTC P1381 will set.

  1. The vehicle speed is above 16 km/h (10 mph).
  2. The engine speed is less than 5,000 RPM.
  3. The engine load is less than 87 percent.
  4. Engine misfire is detected-DTC P0300 set.
  1. A serial data malfunction exists preventing the PCM from receiving rough road detection data.
  2. The above conditions met for 5 seconds.
  1. The control module stores the DTC information into memory when the diagnostic runs and fails.
  2. The malfunction indicator lamp (MIL) will not illuminate.
  3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
  4. The driver information center, if equipped, may display a message.
  1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
  2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
  3. Clear the DTC with a scan tool.

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

  1. 1: This step will diagnose a malfunction in the serial data circuits.
StepActionYesNo
1Did you perform the Diagnostic System Check-Engine Controls?Go to Diagnostic System Check - ABS in Antilock Brake SystemGo to Diagnostic System Check - Engine Controls

DTC P1381

The exhaust gas recirculation (EGR) valve position sensor is monitored by the powertrain control module (PCM). The 5-volt reference circuit, low reference circuit and the EGR valve position signal circuit are used by the PCM to determine the EGR valve position. When the ignition switch is turned ON, the PCM records the EGR Learned Minimum Position. The PCM compares the EGR Learned Minimum Position parameter to the EGR Position Sensor parameter. If the PCM detects that the EGR valve is still open when the PCM is commanding the EGR valve closed, DTC P1404 sets.

  1. The engine is running.
  2. The Ignition 1 Signal voltage parameter is more than 11 volts.
  3. The EGR valve is commanded to 0 percent for 20 seconds after the EGR valve has been commanded to open more than 40 percent for 0.5 seconds.
  4. The EGR command will be disabled if the startup engine coolant temperature (ECT) is less than 5°C (41°F) and will not enable until the ECT is more than 75°C (167°F).
  1. The EGR Position Sensor parameter is 0.23 volts more than the EGR Learned Minimum Position parameter when the Desired EGR Position parameter is commanded to 0 percent for 20 seconds.
  2. The EGR Position Sensor parameter is more than 40 percent and is steady for 0.5 seconds after a test failure and before the next test will be run.
  3. The above conditions are met 4 times.
  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.
  1. Inspect for excessive deposits on the EGR valve pintle or seat. Remove the EGR valve and check for deposits that may interfere with the EGR valve pintle extending completely or cause the pintle to stick.
  2. If the problem is intermittent, refer to «Intermittent Conditions»(/buick/rendezvous/i-2001-2007/remont/testing-diagnostics/#engine-controls-34l-troubleshooting__intermittent-conditions) .

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

  1. 3: This step verifies that the malfunction is present.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Is DTC P0641 also set?Go to DTC P0641Go to Step 3
3Start the engine. Observe the EGR Position Sensor parameter with a scan tool. Is the EGR Position Sensor parameter less than the specified value?1%Go to Step 4Go to Step 6
4Turn ON the ignition, with the engine OFF. Command the exhaust gas recirculation (EGR) valve from 0 percent to 100 percent with a scan tool. Is the EGR Position Variance parameter less than the specified value?15%Go to Step 5Go to Step 7
5Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. 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 6Go to Diagnostic Aids
6Turn OFF the ignition. Disconnect the EGR valve. Turn ON the ignition, with the engine OFF. Observe the EGR Position Sensor parameter with a scan tool. Is the EGR Position Sensor parameter less than the specified value?1%Go to Step 7Go to Step 10
7Connect a test lamp between the 5-volt reference circuit of the EGR valve and the low reference circuit of the EGR valve. Does the test lamp illuminate?Go to Step 8Go to Step 9
8Connect a 3-amp fused jumper wire from the 5-volt reference circuit of the EGR valve to the EGR valve position signal circuit. Is the EGR Position Sensor parameter on the scan tool more than the specified value?99%Go to Step 14Go to Step 12
9Connect a test lamp between the 5-volt reference circuit of the EGR valve and a good ground. Does the test lamp illuminate?Go to Step 11Go to Step 13
10Test the EGR valve position 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 19Go to Step 16
11Test the low reference circuit of the EGR valve 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 19Go to Step 16
12Test the EGR valve position signal circuit for high resistance or for a high resistance short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 19Go to Step 16
13Test the 5-volt reference circuit of the EGR valve 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 19Go to Step 15
14Test for an intermittent and for a poor connection at the EGR valve. 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 19Go to Step 17
15Test all 5-volt reference circuits 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 19Go to Step 16
16Test for an intermittent and for a poor connection at the powertrain control module (PCM). 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 19Go to Step 18
17Replace the EGR valve. Refer to Exhaust Gas Recirculation (EGR) Valve Replacement . Did you complete the replacement?Go to Step 19
18Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . Did you complete the replacement?Go to Step 19
19Clear 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 20
20Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) ListSystem OK

DTC P1404

Output driver modules (ODMs) are chips that are inside the powertrain control module (PCM). The ODMs provide grounded outputs that control devices. Each output has an internal feedback circuit that connects to the PCM microprocessor. The ODM 1 determines if the voltage or the current may cause damage to the PCM. The PCM monitors voltage through the ignition 1 input. Any incorrect current that is on a circuit to the ODM will cause the ODM to report this DTC.

The ignition is ON.

  1. The ODM has detected a voltage greater than 33 volts. or
  2. Excessive current is detected on any circuit to the ODM.
  3. The conditions are present for 30 seconds.
  1. The control module stores the DTC information into memory when the diagnostic runs and fails.
  2. The malfunction indicator lamp (MIL) will not illuminate.
  3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
  4. The driver information center, if equipped, may display a message.
  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.

An over charging condition may set this DTC. Refer to Diagnostic System Check - Engine Electrical in Engine Electrical.

Thoroughly inspect any circuitry that is suspected of causing the intermittent complaint. Repair the circuits as necessary. Refer to Intermittent Conditions .

StepActionYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1Did you perform the Diagnostic System Check-Engine Controls?Go to Step 2Go to Diagnostic System Check - Engine Controls
2Is DTC P0560 set?Go to Diagnostic System Check - Engine Electrical in Engine ElectricalGo to Step 3
3With a scan tool select the Output Driver Data list. Observe the parameters on the scan tool. Do any parameters indicate a fault present?Go to Step 4Go to Step 5
4Test for a short to voltage on the control circuit of the component that indicated a fault. Did you find and correct the condition?Go to Step 6Go to Step 5
5Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . Did you complete the replacement?Go to Step 6
6Use the scan tool in order to clear the DTCs. Start the engine. Allow the engine to idle until the engine reaches normal operating temperature. Select DTC and the Specific DTC function. Enter the DTC number which was set. Operate the vehicle, with the Conditions for Setting the DTC, until the scan tool indicates the diagnostic ran. Does the scan tool indicate that the diagnostic passed?Go to Step 7Go to Step 2
7With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed?Go to Diagnostic Trouble Code (DTC) ListSystem OK

DTC P1640

See also:
• Symptoms - Engine Controls
• Intermittent Conditions
• Engine Controls Schematics
• Engine Controls Connector End Views
• Powertrain Control Module (PCM) Connector End Views
• Diagnostic System Check - Engine Controls
• Testing for Intermittent Conditions and Poor Connections
• Connector Repairs
• Circuit Testing
• Wiring Repairs
• Powertrain Control Module (PCM) Replacement
• Diagnostic Trouble Code (DTC) List
• Service Programming System (SPS)
• Diagnostic System Check - Instrument Cluster
• Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement
• Inducing Intermittent Fault Conditions
• Testing for Continuity
• DTC P0113
• Testing for Electrical Intermittents
• Scan Tool Data List
• Silicon Contamination of Heated Oxygen Sensors Notice
• Heated Oxygen and Oxygen Sensor Notice
• Heated Oxygen Sensor (HO2S) Wiring Repairs
• Diagnostic System Check - ABS
• Diagnostic System Check - Engine Electrical
• DTC P0641

More articles — Engine Performance