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

DTC P0014: Exhaust Camshaft Position (CMP) System Performance

Diagnostic Fault Information

Circuit

Short to Ground

Open

Short to Voltage

Signal Performance

Exhaust CMP Actuator Solenoid Control

P2090

P0013

P2091

P0014

Exhaust CMP Actuator Solenoid Ignition Voltage

--

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 50 degrees. The control module increases the pulse width to accomplish the desired camshaft operation.

Conditions for Running the DTC

P0013

The engine is running.

P0014

    • The engine speed is more than 1,350 RPM.
    • The engine control module (ECM) has enabled the CMP actuator.
    • The system voltage is more than 11 volts.
    • DTC P0014 runs continuously when the above conditions are met.

Conditions for Setting the DTC

P0013

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

P0014

    • The control module has enabled the CMP actuator.
    • The difference between the desired CMP actuator angle and the actual CMP actuator angle is more than 6 degrees.
    • The CMP actuator is steady for 3 seconds.
    • The condition is present for 13.5 seconds.

Action Taken When the DTC Sets

DTC P0013 and P0014 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTC P0013 and P0014 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

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

Electrical Information Reference

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

Scan Tool Reference

Scan Tool Data List

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, 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 Exh. CMP variance parameter. The Exh. CMP variance will rise for 1-2 seconds until the Exh. CMP Angle parameter matches the Desired Exh. CMP parameter. The Exh. 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 CMP actuator to 24 degrees. The desired CMP parameter should match the CMP Angle parameter.

Circuit/System Testing

  1. Ignition OFF, disconnect the Exh. CMP actuator solenoid harness connector at the CMP actuator solenoid.
  2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal A and ground.
  3. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test or replace the Exh. CMP actuator solenoid.
  4. Connect a test lamp between the control circuit terminal B and the ignition circuit terminal A.
  5. Command the Exh. CMP actuator solenoid ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
  6. 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.
  7. Determine that the vehicle has the correct engine oil. Refer to Service and Appearance Care in the owners manual.
  8. 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.
  9. Inspect each CMP actuator solenoid valve assembly for the following:
  10. • Torn screens
    • Debris on the screens
    • Debris clogging the oil ports
    • Missing screens
    • Oil seepage at the solenoid connector pins
  11. Inspect for the following conditions:
  12. • Excessive timing chain play
    • Proper installation of the CMP actuator assembly
  13. If all circuits test normal, test or replace the CMP actuator solenoid.

Component Testing

  1. Measure the resistance of CMP actuator solenoid valve assembly. Resistance should be between 8-15 ohms.
  2. Connect a jumper wire between the CMP actuator solenoid control circuit at the solenoid and a good ground. Connect a fused jumper wire to the CMP actuator solenoid ignition voltage circuit at the solenoid. Momentarily touch the fused jumper to B+. The spool valve should move from fully closed to fully opened position.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Control Module References for replacement, setup, and programming
    •  Camshaft Position Sensor Replacement - Exhaust