Express 1/2 Ton Van V8-5.7L VIN R (1999)
Crankshaft Position Sensor: Service and Repair
CKP System Variation Learn Procedure
1. Install the scan tool.
2. Apply the vehicle's parking brake.
3. Block the drive wheels.
4. Close the hood.
5. Place the vehicle's transmission in Park (A/T) or Neutral (M/T).
6. Idle the engine until the coolant temperature reaches 65°C (150°F).
7. Turn OFF all the accessories.
IMPORTANT: If the CKP System Variation Learn Procedure cannot be completed successfully, refer to DTC P1336 Crankshaft Position (CKP)
System Variation Not Learned for additional diagnostic information.
8. Enable the Crankshaft Position System Variation Learn Procedure with the scan tool.
IMPORTANT: After the ignition switch is turned to the CRANK position, the VCM must see a change in the state of brake switch (Released to
Applied) to run the learn procedure. Also, the service brakes, not the parking brake, must be held throughout the duration of the learn procedure.
9. Apply and hold the service brakes.
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 will respond to throttle position after the learn procedure is complete.
10. Slowly raise the engine speed to 4000 RPM.
11. Immediately release the throttle when the engine speed decreases.
12. Turn OFF the ignition for 15 seconds after the learn procedure is completed successfully.
