Crankshaft Position (CKP) Sensor Variation Learn Procedure (4.3L, 5.7L & 7.4L Except Calif.)

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Procedure must be performed if any of the following have been done:
- EEPROM was reprogrammed.
- If crankshaft position sensor was removed or replaced.
- Vehicle Control Module (VCM) was replaced.
Install scan tool on Data Link Connector (DLC). Apply parking brake. Block rear wheels. Ensure hood is closed.
Place transmission in Park (A/T models) or Neutral (M/T models). Start engine and warm engine until engine coolant temperature is at least 150°F (65°C). Ensure all accessories are off.
Apply service brakes. With engine idling, use scan tool to select and enable CKP sensor variation learn procedure.
Gradually accelerate engine to 4000 RPM. Quickly release throttle to idle position once CKP sensor variation learn procedure is obtained and engine starts to decelerate. Once CKP sensor variation values are learned, the VCM will return engine control to the operator and engine will respond to throttle position.
CAUTION: Ensure throttle is quickly released to idle position once CKP sensor variation learn procedure fuel cut off is obtained and engine starts to decelerate.
If CKP sensor variation learn procedure was completed, turn ignition off for at least 15 seconds and remove scan tool. If CKP sensor variation learn procedure was not completed, a DTC P1336 should be stored in the VCM. Perform test procedures for DTC P1336 and repair as necessary. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.