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 P0016: Crankshaft Position (CKP) - Intake Camshaft Position (CMP) Correlation

DTC P0017: Crankshaft Position (CKP) - Exhaust Camshaft Position (CMP) Correlation

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.

Ignition voltage is supplied directly to the CMP actuator solenoid. The ECM controls the solenoid by grounding the control circuit with a solid state device called a driver. The ECM compares the camshaft position or the camshaft angle, to the position of the crankshaft.

Conditions for Running the DTC

    • Before the ECM can report DTC P0016 or P0017 failed, DTCs P0010, P0011, P0013, P0014, P0335, P0336, P0338, P0341, P0342, P0343, P0366, P0367, P0368, P2088, P2089, P2090, and P2091 must run and pass.
    • The engine is operating for greater than 50 seconds.
    • The engine coolant temperature is between 0-95°C (32-203°F).
    • The calculated engine oil temperature is less than 120°C (248°F).
    • The DTCs run continuously when the above conditions are met for approximately 10 minutes.

Conditions for Setting the DTC

    • The ECM detects one of the following conditions:
       - The ECM detects a deviation in the relationship between a camshaft and the crankshaft.
       - A camshaft is greater than 9.9 degrees advanced in relationship to the crankshaft.
       - A camshaft is greater than 9.9 degrees retarded in relationship to the crankshaft.
    • The ECM detects the difference between an actual intake camshaft angle and the locked position angle is greater than 15 degrees.
    • The ECM detects the difference between an actual exhaust camshaft angle and the locked position angle is greater than 21 degrees.
    • The DTCs are set when the above conditions are met for greater than 4 seconds or a cumulative of 50 seconds.

Action Taken When the DTC Sets

DTCs P0016 and P0017 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0016 and P0017 are Type B DTCs.

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

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 scan tool control of the CMP actuator is inhibited when DTC P0016 or P0017 sets.

  1. Start the engine.
  2. Allow the engine to reach normal operating temperature.
  3. Allow the engine to idle.
  4. With a scan tool, monitor the Desired Exh. and Int. CMP, the Exh. and Int. CMP Angle, and the Exh. and Int. CMP Variance parameters. All parameters should display less than 1 degree.
  5. Using the scan tool output control function, command the CMP actuator to 25 degrees. The Desired CMP and the CMP Angle parameter should display 25 degrees. The CMP Variance Angle will rise for 2-3 seconds until the Desired and Actual parameters values match, then the CMP Variance parameter should return to zero degrees.
  6. If the vehicle passes the Circuit/System Verification Test, then operate the vehicle within the Conditions For Running The DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

Circuit/System Testing

    Important: Incorrect engine oil viscosity, aftermarket engine oil additives, or engine oil that is overdue for changing, can greatly affect the performance of the camshaft actuator.

  1. Ignition OFF, inspect the crankshaft balancer bolt for the proper torque. Refer to Fastener Tightening Specifications.
  2. Inspect the CMP actuator for binding or being stuck.
  3. Inspect the engine for the following conditions:
  4. • An incorrectly installed camshaft sensor
    • An incorrectly installed crankshaft sensor
    • An incorrectly installed camshaft actuator
    • Incorrect valve timing
    • A loose camshaft reluctor wheel
    • A loose crankshaft reluctor wheel
    • Excessive crankshaft end play

Component Testing

  1. Measure the resistance of the CMP actuator solenoid valve assembly. Resistance should be between 8-15 ohms.
  2. Connect a fused jumper wire between the CMP actuator powertrain main relay fused supply circuit terminal A at the solenoid and B+. Connect a jumper wire to the camshaft phaser solenoid control circuit terminal B at the solenoid. Momentarily touch the jumper wire to ground. Observe the spool valve inside the CMP actuator. The spool valve should move from fully closed to fully opened position.
  3. If the spool valve inside the CMP actuator solenoid does not move, replace the CMP actuator solenoid.
  4. Inspect each CMP actuator solenoid valve assembly for the following:
  5. • Torn screens
    • Debris on the screens
    • Debris clogging the oil ports
    • Missing screens
    • Oil seepage at the solenoid connector pins

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Camshaft Position Actuator Solenoid Valve Replacement
    •  Camshaft Position Exhaust Actuator Replacement
    •  Camshaft Position Intake Actuator Replacement
    •  Camshaft Position Sensor Replacement - Exhaust
    •  Camshaft Position Sensor Replacement - Intake
    •  Camshaft Timing Chain, Sprocket, and Tensioner Replacement
    •  Crankshaft and Bearing Cleaning and Inspection
    •  Crankshaft Balancer Replacement
    •  Crankshaft Position Sensor Replacement