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 P0010: Intake Camshaft Position (CMP) Actuator Solenoid Control Circuit Bank 1

DTC P0011: Intake Camshaft Position (CMP) System Performance Bank 1

DTC P0013: Exhaust Camshaft Position (CMP) Actuator Solenoid Control Circuit Bank 1

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

DTC P0020: Intake Camshaft Position (CMP) Actuator Solenoid Control Circuit Bank 2

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

DTC P0023: Exhaust Camshaft Position (CMP) Actuator Solenoid Control Circuit Bank 2

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

Diagnostic Fault Information

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

CMP Actuator Solenoid High Control

P0010, P0013, P0020, P0023

P0010, P0013, P0020, P0023

P0010, P0013, P0020, P0023

P0010, P0013, P0020, P0023

P0011, P0014, P0021, P0024

CMP Actuator Solenoid Low Reference

--

P0010, P0013, P0020, P0023

P0010, P0013, P0020, P0023

--

--

Circuit/System Description

The camshaft position (CMP) actuator is attached to each camshaft and is hydraulically operated in order to change the angle of the camshaft relative to crankshaft position (CKP) . The CMP actuator solenoid is controlled by the engine control module (ECM) . The ECM sends a pulse width modulated 12-volt signal to each CMP actuator solenoid. The solenoid controls the amount of engine oil flow to the CMP actuator by extending a pintle within the solenoid. The pintle acts against a spool valve in the CMP actuator mechanism which is attached to the front of each camshaft. As the spool valve is moved, oil is directed to the CMP actuator, which rotates the camshaft. The CMP actuator can change the cam angle a maximum of 27 degrees.

Conditions for Running the DTC

P0010, P0013, P0020, or P0023

    • The ignition is in Crank or Run.
    • The system voltage is between 11-18 volts.
    • DTCs P0010, P0013, P0020, and P0023 run continuously when the above conditions are met.

P0011, P0014, P0021, or P0024

    • DTCs P0010, P0016, P0017, P0018, P0019, P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, or P0391 are not set.
    • The system voltage is between 11-18 volts.
    • The engine is running.
    • The ECM has enabled the CMP actuator and commanded greater than 0 degrees.
    •  DTC P0011, P0014, P0021, P0024 runs continuously when the above conditions are met.

Conditions for Setting the DTC

P0010, P0013, P0020, or P0023

The ECM detects that the state of the driver and the state of the circuit do not match. The ECM will detect an open, short to ground, or a short to voltage on the high control circuit or an open on the low reference circuit for more than 3.0 seconds.

P0011, P0014, P0021, or P0024

  1. Each CMP angle from the ECM is stable. If the CMP angle varies more than 4.5 cam degrees, then a stability timer of 1 second must expire before evaluating fail condition.
  2. The difference between the desired CMP and the actual CMP angle is more than 5 degrees for 10 seconds during a 300-second sample.

Action Taken When the DTC Sets

    • DTCs P0010, P0011, P0013, P0014, P0020, P0021, P0023, P0024 are Type B DTCs.
    • The CMP actuators are commanded to the home or parked position.

Conditions for Clearing the MIL/DTC

DTCs P0010, P0011, P0013, P0014, P0020, P0021, P0023, P0024 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Control Module Connector End Views
    •  Engine Controls Connector End Views

Description and Operation

    •  Engine Control Module Description
    •  Camshaft Actuator System Description
    •  Lubrication 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

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Circuit/System Verification

    Important: The supply of clean pressurized engine oil to the CMP actuator is essential to CMP actuator performance.

  1. Observe the engine oil level. The engine oil level should be within operating range. Refer to Approximate Fluid Capacities .
  2. Ensure that the vehicle has the correct engine oil and is not old, burnt or contains additives. Refer to Checking Things Under the Hood in Service and Appearance Care within the Owner's Manual.
  3. If the vehicle has the incorrect engine oil, is old, burnt, or contains additives then change the oil and filter.
  4. Test the engine oil pressure for correct operation. Refer to Oil Pressure Diagnosis and Testing .
  5. Allow the engine to reach operating temperature.
  6. Set the parking brake and place the vehicle in park for automatic, or neutral for manual.
  7. Observe the applicable CMP variance parameter. The CMP Variance will rise for 1-2 seconds until the CMP Angle parameter matches the Desired CMP parameter. The CMP Variance should again return to 0 degrees.
  8. Important: The engine will run rough and may require throttle input to keep running.

  9. Command the applicable CMP actuator to 20 degrees. The Desired CMP parameter should match the CMP Angle parameter.

Circuit/System Testing

Important: You must complete the Circuit/System Verification before proceeding with Circuit/System Testing.

P0010, P0013, P0020, or P0023

  1. Ignition OFF, disconnect the affected CMP actuator solenoid harness connector at the CMP actuator solenoid.
  2. Test for less than 1 ohm of resistance between the low reference circuit and ground.
  3. If greater than 1 ohm, test the low reference for an open/high resistance. If the circuit tests normal replace the ECM.
  4. Connect a test lamp between the high control circuit and the low reference circuit.
  5. Command the affected CMP actuator solenoid ON and OFF. The test lamp should turn ON and OFF when changing between commanded states.
  6. If the test lamp is always ON, test the high control circuit for a short to voltage. If the circuit tests normal replace the ECM.
    If test lamp is always OFF, test the control circuit for a short to ground, an open/high resistance. If the circuit tests normal replace the ECM.
  7. If all circuits test normal, test or replace the applicable CMP Actuator solenoid.

P0011, P0014, P0021, or P0024

    • Test for less than 1 ohm of resistance between the applicable CMP actuator solenoid low reference circuit and ground.
       ⇒If greater than 1 ohm, test the low reference for an open/high resistance. If the circuit tests normal, replace the applicable CMP actuator solenoid.
    • Test for less than 1 ohm of resistance on the applicable CMP actuator solenoid high control circuit.
       ⇒If greater than 1 ohm, test the high control circuit for an open/high resistance. If the circuit tests normal, replace the applicable CMP actuator solenoid.
    • Inspect the affected CMP actuator. Refer to the camshaft position actuators in Camshaft Timing Drive Components Cleaning and Inspection and Engine Front Cover Cleaning and Inspection .
    • Inspect the engine timing components. Refer to Camshaft Timing Drive Components Cleaning and Inspection .

Component Testing

Static Test

  1. Ignition OFF, disconnect the CMP actuator solenoid harness connector at the CMP actuator solenoid.
  2. Important: Ensure component is tested at 20°C (68°F).

  3. Test for 4.6-7.5 ohms of resistance between the high control terminal A and the low reference terminal B of the CMP actuator solenoid.
  4. If the resistance is not within the specified range, replace the CMP actuator solenoid.

Dynamic Test

    Important: Do not allow the solenoid to be energized for more than 2 seconds.

  1. Install fused jumper wire between the high control and 12 volts. Install a jumper wire between the low reference and momentarily connect to ground.
  2. Point the CMP actuator solenoid towards a shop towel. Observe the operation of the solenoid immediately extends.
  3. If the function does not perform as specified, replace the CMP actuator solenoid.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Control Module References for ECM replacement, setup, and programming
    •  Camshaft Position Actuator Replacement - Bank 2 (Left Side) Exhaust
    •  Camshaft Position Actuator Replacement - Bank 1 (Right Side) Exhaust
    •  Camshaft Position Actuator Replacement - Bank 2 (Left Side) Intake
    •  Camshaft Position Actuator Replacement - Bank 1 (Right Side) Intake
    •  Camshaft Timing Drive Components Cleaning and Inspection for timing chain, sprockets, CMP actuator filter screen, and CMP actuator replacement