Crankshaft Position System Variation Learn

CKP SYSTEM VARIATION LEARN PROCEDURE

IMPORTANT:
- The crankshaft position (CKP) system variation learn procedure is required when the following service procedures have been performed, regardless of whether DTC P0315 is set:
- Engine replacement
- Engine control module (ECM) replacement
- Crankshaft damper replacement
- Crankshaft replacement
- CKP sensor replacement
- Any engine repairs which disturb the crankshaft to CKP sensor relationship
- The scan tool monitors certain component signals to determine if all the conditions are met to continue with the CKP system variation learn procedure. The scan tool only displays the condition that inhibits the procedure. The scan tool monitors the following components:
- CKP sensor activity-If there is a CKP sensor condition, refer to the applicable DTC that set.
- Camshaft position (CMP) signal activity-If there is a CMP signal condition, refer to the applicable DTC that set.
- 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.

1. Install a scan tool.
2. Monitor the 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. Diagnostic Trouble Code Descriptions
3. With a scan tool, select the CKP system variation learn procedure within the Special Functions menu and perform the following:
1. Observe the fuel cut-off for the applicable engine.
2. Block the drive wheels.
3. Set the parking brake.
4. Place the vehicle's transmission in Park or Neutral.
5. Turn the air conditioning (A/C) OFF.
6. Cycle the ignition from OFF to ON.
7. Apply and hold the brake pedal for the duration of the procedure.
8. Start and idle the engine.
9. Accelerate to wide open throttle (WOT). The engine should not accelerate beyond the calibrated fuel cut-off RPM value noted in step 3.1. Release the throttle immediately if the value is exceeded.
10. Release the throttle when fuel cut-off occurs.

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.

4. 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, or if any other DTCs set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for the applicable DTC that set. Diagnostic Trouble Code Descriptions
5. Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully.