GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2008 🢒 LaCrosse 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P0011, P0014, P0021, or P0024

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 (CMP) System Performance Bank 1

DTC P0014: Exhaust Camshaft Position (CMP) System Performance Bank 1

DTC P0021: Intake Camshaft Position (CMP) System Performance Bank 2

DTC P0024: Exhaust Camshaft Position (CMP) System Performance Bank 2

Circuit/System Description

The camshaft position (CMP) actuator system enables the engine control module (ECM) to change the timing of the camshafts while the engine is operating. The CMP actuator solenoid signal from the ECM is pulse width modulated (PWM). The ECM controls the CMP actuator solenoid duty cycle by controlling the amount of solenoid ON time. The CMP actuator solenoid controls the advance or the retard of each camshaft. The CMP actuator solenoid 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 500 RPM.
    • 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 2-10 cam control cycles for at least 2.5 seconds each in the phased position.
    • The engine is operating for greater than 2 seconds.
    • 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 that the desired camshaft position angle is +/-6 degrees of the actual camshaft position angle.
    • The condition exists for greater than 4 seconds, or for a cumulative of 50 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.

Diagnostic Aids

The following table illustrates the ECM connector locations:

ECM Connector Location

X2

X1

Front of Vehicle

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

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 Engine Oil Life parameter with a scan tool. 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

    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.

  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, or P0523.
    2. ⇒If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
  2. Engine idling, command the suspected camshaft actuator from 0 degrees to 40 degrees and back to zero while observing the appropriate scan tool CMP Angle Variance parameters. The CMP Angle Variance should be less than 2 degrees in each of the commanded states.
  3. 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 are captured in the Freeze Frame/Failure Records Data List.

Circuit/System Testing
  1. Ignition OFF, disconnect the harness connector at the appropriate camshaft position (CMP) actuator solenoid.
  2. Ignition ON, load test for B+ between the ignition voltage circuit terminal 1 and ground.
    3. ⇒If less than the specified range, repair the ignition voltage circuit for an open/high resistance.

    Important:  Use a test lamp that measures greater than 20 ohms for this test.

  3. Connect a test lamp between the control circuit terminal 2 and B+.
  4. Command the appropriate CMP actuator solenoid ON and OFF with a scan tool. The test lamp should respond to the scan tool commands.
    5. ⇒If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
    ⇒If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.

    Important:  The voltage must be measured at the control side of the circuit.

  5. Command the appropriate CMP actuator solenoid ON with a scan tool. Test for less than 1 volt between the probe of the test lamp and the ECM housing.
    6. ⇒If greater than the specified value, test the control circuit for a high resistance. If the circuit/connections test normal, replace the ECM.
  6. Remove the CMP actuator solenoid. Inspect the CMP actuator solenoid and mounting area for the following conditions:
    7. • For a torn, restricted, mispositioned, or missing screens at the CMP actuator solenoid
    • For engine oil leaks between the oil sealing lands of the CMP actuator solenoid--Inspect the lands of the CMP actuator solenoid for nicks.
    • For oil seepage at the CMP actuator solenoid connector
    ⇒If a condition is found, replace CMP actuator solenoid.
  7. Ignition OFF, swap the suspected CMP actuator solenoid with a CMP actuator solenoid that is operating correctly.
  8. Engine idling, command the suspected camshaft actuator from 0 degrees to 40 degrees and back to zero while observing the appropriate CMP Angle Variance parameters, with a scan tool. The CMP Angle Variance should be less than 2 degrees in each of the commanded states.
    9. ⇒If the CMP Angle Variance is greater than 2 degrees, replace the camshaft position (CMP) actuator.
  9. If all circuits/connections test normal, test or replace the CMP actuator solenoid.

Component Testing
  1. Test for 7-12 ohms of resistance between the terminals of the CMP actuator solenoid.
    2. ⇒If not within the specified range, replace the CMP actuator solenoid.
  2. Test for infinite resistance between each terminal of the CMP actuator solenoid and the CMP actuator solenoid housing.
    3. ⇒If less than the specified range, replace the 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