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 P0011: Intake Camshaft Position System Performance Bank 1

DTC P0014: Exhaust Camshaft Position System Performance Bank 1

DTC P0021: Intake Camshaft Position System Performance Bank 2

DTC P0024: Exhaust Camshaft Position System Performance Bank 2

Circuit/System Description

The camshaft position actuator system enables the engine control module (ECM) to change the timing of the camshafts while the engine is operating. The CMP actuator solenoid valve signal from the ECM is pulse width modulated (PWM). The ECM controls the CMP actuator solenoid valve duty cycle by controlling the amount of solenoid valve ON time. The CMP actuator solenoid valve controls the advance or the retard of each camshaft. The CMP actuator solenoid valve controls the oil flow that applies the pressure to advance or retard the camshafts.

Conditions for Running the DTC

    • Before the ECM can report DTC P0011, P0014, P0021, or P0024 failed, DTCs P0010, P0013, P0020, P0023, P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, P0393, P2088, P2089, P2090, P2091, P2092, P2093, P2094, and P2095 must run and pass.
    • DTC P0016, P0017, P0018, P0019, P0335, P0336, or P0338 is not set.
    • The engine speed is greater than 480 RPM.
    • The engine coolant temperature (ECT) is between -48 to +143°C (-54 to +289°F).
    • The engine oil temperature is between -48 to +180°C (-54 to +356°F).
    • The engine must accelerate such that the CMP actuator system is commanded from the park position to the phased position. This is considered a cam control cycle. There must be a total of 4-10 cam control cycles for at least 2.5 seconds each in the phased position.
    • The engine is operating for greater than 1 second.
    • DTCs P0011, P0014, P0021, and P0024 run continuously once the above conditions are met for greater than 20 seconds.

Conditions for Setting the DTC

    • The ECM detects the difference between the desired camshaft position and the actual camshaft position angle is greater than 5 degrees.
        OR
    • The ECM detects the difference between the actual camshaft angle and the locked position angle is greater than 1.5 degrees.
    • The condition exists for greater than 1 second or cumulative of 5 seconds.

Action Taken When the DTC Sets

DTCs P0011, P0014, P0021, and P0024 are type B DTCs.

Conditions for Clearing the DTC

DTCs P0011, P0014, P0021, and P0024 are type B 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

Special Tools

    • J 35616-200 Test Lamp Kit
    • For equivalent regional tools, refer to Special Tools.

Diagnostic Aids

    • The engine oil condition has a major impact on the camshaft actuator system.
    • A low oil level condition may set this DTC. The engine may require an oil change. Inquire with the customer when the last oil change was performed. You may also monitor the scan tool Engine Oil Life parameter. Advise the customer an oil change may be required.
    • Inspect the engine for any recent engine mechanical repairs. An incorrectly installed camshaft, camshaft actuator, or timing chain can cause this DTC to set.

Circuit/System Verification

    Note: The engine oil level and the oil pressure are critical to the correct operation of the camshaft position actuator system. Verify that the engine has the correct oil level and the correct oil pressure before continuing with this diagnostic.

  1. Ignition ON, observe the scan tool DTC information. Verify that none of the following DTCs are set. DTC P0016, P0017, P0018, P0019, P0335, P0336, P0338, P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, P0393, P0521, P0522, P0523, P0638, P2100, P2101, P2102, P2103, or P2119.
  2. If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
  3. Engine idling, command the appropriate Camshaft Position Actuator from 0 degrees to 40 degrees and back to zero while observing the appropriate scan tool Camshaft Position Variance parameters. The Camshaft Position Variance should be less than 2 degrees in each of the commanded states.
  4. 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

  1. Ignition OFF, disconnect the harness connector at the appropriate Q6 camshaft position actuator solenoid valve.
  2. Ignition ON, load test for B+ between the ignition circuit terminal 1 and ground.
  3. If less than the specified range, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary.

    Note:  Use the j 35616-200 Test Lamp Kit for this test. If the j 35616-200 Test Lamp Kit is not available, use a test lamp that measures greater than 20 Ω.

  4. Connect a test lamp between the control circuit terminal 2 and B+.
  5. Note:  The voltage must be measured at the control side of the circuit.

  6. Command the appropriate Camshaft Position Actuator Solenoid Valve ON with a scan tool. Load test for less than 1 V between the control circuit terminal 2 and ground.
  7. If greater than the specified range, test the control circuit for an open/high resistance. If the circuit/connections test normal, replace the K20 ECM.
  8. Remove the CMP actuator solenoid valve. Inspect the CMP actuator solenoid valve and mounting area for the following conditions:
  9. • For a torn, restricted, mis-positioned, or missing screens at the CMP actuator solenoid valve
    • For engine oil leaks between the oil sealing lands of the CMP actuator solenoid valve. Inspect the lands of the CMP actuator solenoid valve for nicks
    • For oil seepage at the CMP actuator solenoid valve connector
    If a condition is found, replace Q6 CMP actuator solenoid valve.
  10. Ignition OFF, swap the appropriate CMP actuator solenoid valve with a CMP actuator solenoid valve that is operating correctly.
  11. Engine idling. Command the appropriate Camshaft Position Actuator from 0 degrees to 40 degrees and back to zero while observing the appropriate scan tool Camshaft Position Variance parameters. The Camshaft Position Variance should be less than 2 degrees in each of the commanded states.
  12. If greater than the specified value, replace the mechanical camshaft position actuator.
  13. If all circuits/connections test normal, test or replace the Q6 CMP actuator solenoid valve.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate Q6 camshaft position actuator solenoid valve.
  2. Test for 7-12 Ω between the control terminal 2 and the ignition terminal 1 of the Q6 camshaft position actuator solenoid valve.
  3. If not within the specified range, replace the Q6 CMP actuator solenoid valve.
  4. Test for infinite resistance between each terminal and the Q6 CMP actuator solenoid valve housing.
  5. If not the specified value, replace the Q6 CMP actuator solenoid valve.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Intake
    •  Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Exhaust
    •  Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 2 (Left Side) Intake
    •  Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 2 (Left Side) Exhaust
    •  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
    •  Control Module References for engine control module replacement, setup, and programming