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

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

DTC P0023: Exhaust Camshaft Position (CMP) Actuator Solenoid Control Circuit 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 20 degrees.

Conditions for Running the DTC

    • 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.

Conditions for Setting the DTC

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 seconds.

Action Taken When the DTC Sets

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

Conditions for Clearing the MIL/DTC

DTCs P0010, P0013, P0020, P0023 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
    •  Engine Control Module Description
    •  Lubrication Description

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  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

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

  1. Allow the engine to reach operating temperature.
  2. Set the parking brake and place the vehicle in Park for automatic, or Neutral for manual.
  3. 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.
  4. Important: The engine will run rough and may require throttle input to keep running.

  5. Command the applicable CMP actuator to 20 degrees. The Desired CMP parameter should match the CMP Angle parameter.
  6. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

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

  1. Ignition OFF, disconnect the CMP actuator solenoid harness connector at the CMP actuator solenoid.
  2. Test for less than 5 ohms between the low reference circuit terminal 2 and ground.
  3. If greater than the specified range, test the low reference circuit for an open/high resistance.
  4. Verify that a test lamp does not illuminate between the low reference circuit terminal 2 and the control circuit terminal 1.
  5. If the test lamp illuminates, test the control circuit for short to voltage. If the circuit tests normal, replace the ECM.
  6. Remove the test lamp.
  7. Command the CMP Actuator Sol. ON with a scan tool. Verify the scan tool CMP Sol Ckt Short Gnd Test status is OK.
  8. If not the specified value, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
  9. Install a 3A fused jumper wire between the control circuit terminal 1 and the low reference circuit terminal 2. Command the CMP Actuator Sol. ON with a scan tool. Verify the scan tool CMP Sol Ckt Short Gnd Test status is Fault.
  10. If not the specified value, test the control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

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 between the high control terminal 1 and the low reference terminal 2 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 terminal 1 and 12 volts. Install a jumper wire between the low reference terminal 2 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.

    •  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
    •  Control Module References for ECM replacement, setup, and programming