GM Service Manual Online
For 1990-2009 cars only
  1. Install a scan tool.
  2. Monitor the powertrain control module (PCM) for DTCs with a scan tool. If other DTCs are set, except DTC P0315, refer to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information for the applicable DTC that set.
  3. Using a scan tool, select the crankshaft position (CKP) variation learn procedure.
  4. The scan tool instructs you to perform the following procedures:
  5. 4.1. Accelerate to wide open throttle (WOT).
    4.2. Release the throttle when the fuel cutoff occurs.
    4.3. Observe the fuel cutoff specifications for the applicable engine.
    4.4. Engine should not accelerate beyond the calibrated RPM value.
    4.5. Release the throttle immediately if the value is exceeded.
    4.6. Block the drive wheels.
    4.7. Set the parking brake.
    4.8. DO NOT apply the brake pedal.
    4.9. Cycle the ignition from OFF to ON.
    4.10. Apply and hold the brake pedal.
    4.11. Start and idle the engine.
    4.12. Turn the A/C OFF.
    4.13. Vehicle must remain in Park or Neutral.
    4.14. The scan tool monitors certain component signals to determine if all the conditions are met to continue with the procedure. The scan tool only displays the condition that inhibits the procedure. The scan tool monitors the following components:
       • The CKP sensor activity--If a CKP sensor condition exists, refer to the applicable DTC that set.
       • The camshaft position (CMP) signal activity--If a CMP signal condition exists, refer to the applicable DTC that set.
       • The engine coolant temperature (ECT)--If the engine coolant temperature is not warm enough, idle the engine until the engine coolant temperature reaches the correct temperature.

    Important: While the learn procedure is in progress, release the throttle immediately when the engine starts to decelerate. The engine control is returned to the operator, and the engine responds to throttle position after the learn procedure is complete.

  6. Using the scan tool, enable the CKP system variation learn procedure. Perform the following procedure:
  7. 5.1. Accelerate to wide open throttle (WOT).
    5.2. Release when the fuel cutoff occurs.
    5.3. Test in progress.
  8. The scan tool displays Learn Status: Learned This Ignition. If the scan tool indicates that DTC P0315 ran and passed, the CKP variation learn procedure is complete. If the scan tool indicates DTC P0315 failed or did not run, refer to DTC P0315 . If any other DTCs set, refer to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information for the applicable DTC that set.
  9. Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully.
  10. The CKP system variation learn procedure is also required when the following service procedures have been performed, regardless of whether DTC P0315 is set:
  11. • An engine replacement
    • A PCM replacement
    • A crankshaft balancer replacement
    • A crankshaft replacement
    • A CKP sensor replacement
    • Any engine repairs which disturb the crankshaft to CKP sensor relationship