CKP System Variation Learn Procedure

CRANKSHAFT LEARN
The PCM uses crankshaft velocity calculations to determine misfire and run misfire self-diagnostics. The PCM must know precisely the variability in crankshaft notches for this function. The PCM has a "notch learn" process that learns the variability between notches which must be reset if the crankshaft in the engine is replaced. With use of the SSS, the crankshaft learn procedure can be set to relearn.


NOTE:
^ Do not transfer PCM's from one vehicle to another. The learned crankshaft notches will be different from one vehicle to another.
^ Anytime a replacement PCM is installed the PCM must relearn the crankshaft notches.

CRANKSHAFT RELEARN PROCEDURE
When a replacement PCM is installed, or the crankshaft or engine has been replaced, follow these procedures to relearn the crankshaft notches:

1. Allow the engine to idle until the SERVICE telltale flashes.
2. Hold rpm level to 3000 rpm until lamp goes Off (approx 10-20 seconds).

NOTE:
^ This procedure will not be initiated if any misfire is detected. If misfire codes are present refer to the appropriate Misfire trouble codes prior to attempting to relearn crankshaft notches.
^ If the Scan tool or service stall system are used to "reset" the crank shaft learn, the ignition will have to be cycled off for 10 seconds to correctly initiate the process.