GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The camshaft position (CMP) actuator system enables the engine control module (ECM) to change the camshaft timing of all 4 camshafts while the engine is operating. The CMP actuator assembly varies the camshaft position in response to directional changes in oil pressure. The CMP actuator solenoid controls the oil pressure that is applied to advance or retard a camshaft.

The CMP actuator assemblies have an outer housing that is driven by the engine timing chain. Inside the CMP assembly is a wheel with fixed vanes that is attached to the camshafts. The CMP actuator assemblies are also equipped with a locking pin. The locking pin prevents movement between the outer housing and the wheel vane assembly on engine start-ups. The CMP actuator is locked until sufficient oil pressure is available to control the CMP actuator. The locking pin is released by oil pressure before any movement in the CMP actuator assembly takes place. If the ECM detects that the CMP actuator is not in the locked position on a start-up, this DTC sets.

DTC Descriptors

This diagnostic procedure supports the following DTCs.

    • DTC P1011 Intake Camshaft Position (CMP) Actuator Park Position Bank 1
    • DTC P1012 Exhaust Camshaft Position (CMP) Actuator Park Position Bank 1
    • DTC P1013 Intake Camshaft Position (CMP) Actuator Park Position Bank 2
    • DTC P1014 Exhaust Camshaft Position (CMP) Actuator Park Position Bank 2

Conditions for Running the DTC

    • DTCs P0010, P0013, P0020, P0023, P2088, P2089, P2090, P2091, P2092, P2093, P2094, and P2095 are not set.
    • The engine is operating for more than 1 second.
    • The ECM completed the CMP actuator solenoid output driver test.
    • The engine speed is more than 1,000 RPM.
    • DTCs P1011, P1012, P1013, and P1014 only runs on an engine start-up.

Conditions for Setting the DTC

The ECM detects that a CMP actuator is not in the parked position on an engine start-up.

Action Taken When the DTC Sets

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

Conditions for Clearing the DTC

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

Diagnostic Aids

    • The following conditions cause DTCs P1011, P1012, P1013, and P1014 to set:
       - Turning the engine OFF while the accelerator pedal is pressed
       - Turning the engine OFF while driving
       - Pressing the accelerator pedal to start the engine
       - An engine idle flare during a start-up
       - An actuator that is in the full advance or retard position
    • For an intermittent condition, refer to Intermittent Conditions .

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

Important: The engine oil level and the oil pressure are critical to the correct operation of the camshaft position (CMP) actuator system. Verify that the engine has the correct oil level and the correct oil pressure before continuing with this diagnostic. Refer to Fluid and Lubricant Recommendations in Maintenance and Lubrication and Oil Pressure Diagnosis and Testing in Engine Mechanical-3.6L (LY7) for more information.

Observe the DTC Information with a scan tool.

Does the scan tool display any ECM DTCs other than DTCs P1011, P1012, P1013, and P1014?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3

Is there an abnormal engine noise on start-up and/or does DTCs P1011, P1012, P1013, and P1014 set?

Go to Camshaft Position Actuator Replacement - Bank 2 (Left Side) Exhaust or Camshaft Position Actuator Replacement - Bank 1 (Right Side) Exhaust or Camshaft Position Actuator Replacement - Bank 2 (Left Side) Intake or Camshaft Position Actuator Replacement - Bank 1 (Right Side) Intake in Engine Mechanical - 3.6L (LY7)

Go to Step 4

4

Is the customer's concern that the engine is stalling?

Go to Symptoms - Engine Controls

Go to Step 5

5

Advise the customer that the following conditions cause DTCs  P1011, P1012, P1013, and P1014 to set:

    • Turning the engine OFF while the accelerator pedal is pressed
    • Turning the engine OFF while driving
    • Pressing the accelerator pedal to start the engine

Did you complete the action?

Go to Step 6

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6

Clear the DTCs with a scan tool.

Did you complete the action?

Go to Step 7

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7

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK