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Crankshaft Position Sensor System Variation Learn Procedure

CAUTION: Before performing Crankshaft Position Sensor (CKP) system variation learn procedure, always set parking brake and block drive wheels in order to prevent personal injury. Release throttle immediately when engine starts to decelerate in order to eliminate over revving engine. Once learn procedure has been completed, control module will return engine control to operator and engine will respond to throttle position.
NOTE: Battery must be fully charged and in good condition. Scan tool connection at DLC should be clean and tight before starting CKP system variation learn procedure.
  1. Install scan tool to DLC.
  2. Using scan tool, monitor PCM for DTCs. If other DTCs are set, except DTC P1336, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .
  3. Select CKP variation learn procedure on scan tool.
  4. Observe fuel cut-off procedure.
  5. Follow scan tool instructions when to block drive wheels, apply parking brake, cycle ignition from off to on, apply and hold brake pedal, start and idle engine, turn A/C off, place transmission in Park (A/T) or Neutral (M/T). Scan tool monitors certain component signals to determine if all conditions are met to continue with procedure. Scan tool only displays condition that inhibits the learn procedure and monitors CKP sensors activity. If there is a CKP or CMP sensor condition, refer to applicable DTC displayed. If ECT is not warm enough, operate engine at idle until ECT reaches specified temperature.
  6. Using scan tool, enable CKP system variation learn procedure.
    7. NOTE: When learn procedure is in progress, release throttle immediately when engine starts to decelerate. Engine control is returned to operator and engine responds to throttle position after learn procedure is complete.
  7. Slowly increase engine speed to observed RPM.
  8. Immediately release throttle when fuel cut-off is reached.
  9. If scan tool displays LEARNED THIS IGNITION, go to next step. If scan tool does not display LEARNED THIS IGNITION and no additional DTCs are set, perform POWERTRAIN DIAGNOSTIC SYSTEM CHECK . If a DTC is set, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .
  10. Turn ignition off for 30 seconds after learn procedure is completed successfully.
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