GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    •  Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

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

Circuit/System 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.

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 greater than 1 second.
    • The ECM completed the CMP actuator solenoid output driver test.
    • The engine speed is greater than 1,000 RPM.
    • DTCs P1011, P1012, P1013, and P1014 only run once at engine start-up.

Conditions for Setting the DTC

The ECM detects that average of the actual camshaft angle measurement is greater than 10 degrees of the parked position angle at engine start-up.

Action Taken When the DTC Sets

DTCs P1011, P1012, P1013, and P1014 are Type C DTCs.

Conditions for Clearing the DTC

DTCs P1011, P1012, P1013, and P1014 are Type C DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Camshaft Actuator System Description

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

       Note: The engine oil level and the oil pressure are critical to the correct operation of the 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 and Oil Pressure Diagnosis and Testing for more information.

    • Start the engine. Verify there is no abnormal engine noise during start up.
    • Observe the DTC information with a scan tool. DTC P1011, P1012, P1013, or P1014 should not set.
    • If the vehicle passes the Circuit/System Verification test, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.
    • Inform the customer that the following actions may cause DTC P1011, P1012, P1013, or 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
    • Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

Start the engine.

If there is an abnormal engine noise, or DTC P1011, P1012, P1013, or P1014 set, replace the appropriate CMP actuator.
If the customers concern is that the engine is stalling, refer to Symptoms - Engine Controls for further diagnosis.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Camshaft Position Actuator Replacement - Bank 1 (Right Side) Intake
    •  Camshaft Position Actuator Replacement - Bank 1 (Right Side) Exhaust
    •  Camshaft Position Actuator Replacement - Bank 2 (Left Side) Intake
    •  Camshaft Position Actuator Replacement - Bank 2 (Left Side) Exhaust