Crankshaft Position System Variation Learn Procedure
- Install a scan tool.
- Monitor the engine control module (ECM) for DTCs with a scan tool. If other DTCs are set, except DTC P0315, refer to Diagnostic Trouble Code (DTC) List - Vehicle for the applicable DTC that set.
- Select the crankshaft position (CKP) variation learn procedure with a scan tool.
The scan tool instructs you to perform the following:
- Accelerate to wide open throttle (WOT).
- Release throttle when fuel cut-off occurs.
- Observe fuel cut-off for applicable engine.
- Engine should not accelerate beyond calibrated RPM value.
- Release throttle immediately if value is exceeded.
- Block drive wheels.
- Set parking brake.
- DO NOT apply brake pedal.
- Cycle ignition from OFF to ON.
- Apply and hold brake pedal.
- Start and idle engine.
- Turn A/C OFF.
- Vehicle must remain in Park or Neutral.
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:
CKP sensors activity--If there is a CKP sensor condition, refer to the applicable DTC that set
Enable the CKP System Variation Learn Procedure with a scan tool.
NOTEWhile 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.
- Accelerate to WOT.
- Release when the fuel cut-off occurs.
- Test in progress.
- 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 for the applicable DTC that set.
- Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully.
The CKP Variation Learn Procedure is also required when the following service procedures have been performed, regardless of whether DTC P0315 is set:
- A CKP sensor replacement.
- An engine replacement.
- A ECM replacement.
- A harmonic balancer replacement.
- A crankshaft replacement.
- Any engine repairs which disturb the CKP sensor relationship.
The Crankshaft Position (CKP) sensor senses the crank angle (piston position) of each cylinder and converts it into a pulse signal. The PCM receives this signal and then computes the engine speed and controls the fuel injector timing and ignition timing based on this input.
Removal & Installation
- Raise and safely support the vehicle.
- Remove the starter.
- Working through the wheel well opening, unplug the harness connector from the sensor.
- Clean the area around the sensor to prevent debris from entering the engine.
- Remove the bolt securing the sensor, then remove it from the engine.
- Installation is the reverse of removal. Lubricate a new O-ring with clean engine oil. Tighten the bolt to 18 ft. lbs. (25 Nm).
Connect the scan tool to the vehicle and perform the CKP sensor variation learn procedure.
- Inspect the CKP sensor for correct installation. Remove the CKP sensor from the engine and inspect the sensor O-ring for damage. If the sensor is loose, incorrectly installed, or damaged, replace the CKP sensor.
- Engage the CKP sensor harness connector to the CKP sensor.
- Connect the scan tool to the diagnostic connector.
- With the ignition ON, engine OFF observe the CKP Active counter parameter on the scan tool.
- Pass a flat steel object across the tip of the sensor repeatedly. The CKP Active counter parameter should increment with each pass of the steel object.
- If the parameter does not increment, replace the CKP sensor.