Circuit Description

Crankshaft position system variation learning feature is used to calculate reference period errors caused by slight tolerance variations in crankshaft, crankshaft balancer interrupter rings, and Crankshaft Position (CKP) sensor Hall Effect switches. The calculated error allows PCM to accurately compensate for reference period variations. The crankshaft position system variation learning feature enhances the ability of the PCM to detect misfire events over a wider range of engine speed and load.

NOTE: The crankshaft position system variation learning procedure must be performed any time a change is made to the CKP sensor to crankshaft relationship, or if PCM is replaced or reprogrammed.

DTC P1336 indicates that the crankshaft position system variation values have not been stored in the PCM and the crankshaft position system variation learn procedure must be performed. The learning procedure is required after the following service procedures have been performed, regardless of whether or not DTC P1336 is set:

PCM replacement.
Engine replacement.
Crankshaft balancer replacement.
Crankshaft position sensor replacement.
Any engine repair(s) which disturbs crankshaft/harmonic balancer to crankshaft position sensor relationship.
Conditions required for setting DTC:
No ECT, KS, CKP, CMP or injector sensor DTCs.
PCM has not successfully learned crankshaft position Tooth Error Correction within 5 attempts or 3 miles.