Crankshaft Position System Variation Learn Procedure Scan Tool

A scan tool is essential for performing the Crankshaft Position (CKP) system variation learn procedure. This procedure is required after specific engine repairs or component replacements to ensure proper engine performance and avoid Diagnostic Trouble Code (DTC) P0315. This article outlines the procedure and highlights the critical role of a compatible scan tool.

When is CKP System Variation Learn Required?

The CKP system variation learn procedure is necessary after several service procedures, even if DTC P0315 isn’t active. These include:

• Engine replacement
• Control module replacement
• Crankshaft balancer replacement
• Crankshaft replacement
• CKP sensor replacement
• Any engine repair affecting the crankshaft-to-CKP sensor relationship

Scan Tool’s Role in Monitoring System Readiness

A crucial function of the scan tool is monitoring specific component signals to verify conditions are met for the CKP System Variation Learn Procedure. The scan tool identifies any inhibiting conditions by displaying signals from:

• CKP Sensors: Detects sensor activity; refer to the corresponding DTC for any CKP sensor issues.
• Camshaft Position (CMP) Signal: Detects signal activity; consult the relevant DTC for any CMP signal problems.
• Engine Coolant Temperature (ECT): Ensures the engine is sufficiently warmed up. Idle the engine until the correct temperature is reached if necessary.

CKP System Variation Learn Procedure Using a Scan Tool

The following steps outline the procedure using a compatible scan tool:

1. Connect Scan Tool: Install a scan tool capable of performing the CKP System Variation Learn Procedure.

2. Check for DTCs: Use the scan tool to check for any DTCs besides P0315. If other DTCs are present, diagnose and address them before proceeding.

3. Initiate Learn Procedure: Select the CKP System Variation Learn Procedure on the scan tool.

4. Prepare the Vehicle:

   • Block the drive wheels.
   • Engage the parking brake.
   • Do not apply the brake pedal initially.
   • Cycle the ignition from OFF to ON.
   • Apply and hold the brake pedal throughout the procedure.
   • Start and let the engine idle.
   • Turn off the air conditioning (A/C).
   • Ensure the vehicle remains in Park or Neutral.

5. Perform WOT Test: Accelerate to wide open throttle (WOT) and release when fuel cut-off occurs. Important: Release the throttle immediately when the engine begins decelerating during the learning process. The engine will respond to throttle input after the procedure completes.

6. Verify Learn Status: The scan tool will display “Learn Status: Learned this Ignition” upon successful completion. If DTC P0315 ran and passed, the procedure is complete. If it failed, did not run, or another DTC is present, refer to the relevant DTC list and perform the appropriate diagnostics.

7. Store Learned Values: Turn OFF the ignition for 30 seconds after successful completion to allow the PCM to store the learned CKP system variation values.

Conclusion

The CKP system variation learn procedure is crucial for optimal engine performance after certain repairs. A compatible Crankshaft Position System Variation Learn Procedure Scan Tool is indispensable for this process, enabling technicians to diagnose issues, monitor system readiness, execute the procedure, and verify successful completion. Following the outlined steps and using the scan tool correctly ensures accurate learning and prevents potential drivability problems.