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 Descriptor

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

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Exhaust CMP Actuator Solenoid Control

P0013

P0013

P0013

P0014

Exhaust CMP Actuator Low Reference

--

P0013

--

--

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 control module. The control module sends a pulse width modulated 12-volt signal to a CMP actuator solenoid. The solenoid controls the amount of engine oil flow to a CMP actuator. The CMP actuator can change the camshaft angle a maximum of 25 degrees. The control module increases the pulse width to accomplish the desired camshaft operation.

Conditions for Running the DTC

    • The engine is running.
    • The system voltage is between 11-18 volts.

Conditions for Setting the DTC

The ECM detects an open, short to ground, or a short to voltage on the control circuit or an open on the low reference circuit for more than 0.25 second.

Action Taken When the DTC Sets

DTC P0013 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0013 is a Type B DTC.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ensure the vehicle has the proper oil viscosity.
  2. Observe the engine oil level. The engine oil level should be within the operating range.
  3. Allow the engine to reach operating temperature.
  4. Command the CMP actuator to 20 percent. The CMP actuator angle desired parameter should match the CMP actuator actual parameter.
  5. 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

  1. With the ignition ON, measure for battery voltage between the CMP actuator solenoid control circuit terminal A of the actuator and a ground.
  2. If less than battery voltage, test the CMP actuator control circuit for an open, short to ground. If the circuit tests normal, replace the control module.
  3. Connect a test lamp between the CMP actuator solenoid control of the actuator and a good ground. The test lamp should not illuminate.
  4. If the test lamp illuminates, test the CMP actuator control circuit for a short to voltage. If the circuit tests normal, replace the control module.
  5. Command the CMP actuator solenoid ON and OFF. The test lamp should turn ON and OFF.
  6. If the test lamp does not turn ON and OFF, test the CMP actuator control circuit for high resistance. If the circuit tests normal, replace the control module.
  7. Connect a test lamp between the low reference circuit terminal B of the CMP actuator solenoid of the actuator and battery voltage. The test lamp should illuminate.
  8. If the test lamp does not illuminate, test the low reference circuit for an open, high resistance. If the circuit tests normal, replace the control module.
  9. Determine that the vehicle has the correct engine oil. Refer to Service and Appearance Care in the owner's manual.
  10. If the engine oil life system monitor displays the Change Oil Soon message, the engine oil is more than one year old, contains additives, or is not the correct viscosity, change the oil.
  11. Test the engine oil pressure. Refer to Oil Pressure Diagnosis and Testing.
  12. If the oil pressure is low, correct the low pressure first.
  13. Inspect the CMP actuator solenoid valve assembly for the following:
  14. • Torn screens
    • Debris on the screens
    • Debris clogging the oil ports
    • Missing screens
    • Oil seepage at the solenoid connector pins
  15. Inspect for the following conditions:
  16. • Excessive timing chain play--Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection.
    • Proper installation of the CMP actuator assembly
  17. Test the CMP actuator. Refer to Camshaft Position Actuator Diagnosis.

Component Testing

  1. Measure the resistance of each CMP actuator solenoid valve assembly. Resistance should be between 8-12 ohms.
  2. Connect a jumper wire between the CMP actuator low reference circuit at the solenoid and a good ground. Connect a fused jumper wire to the CMP actuator high control circuit at the solenoid. Momentarily touch the fused jumper to B+. Observe the spool valve inside the CMP actuator. The spool valve should move from fully closed to fully opened position.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Camshaft Position Actuator Solenoid Valve Replacement
    •  Camshaft Position Exhaust Actuator Replacement
    •  Control Module References for replacement, setup, and programming.