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. Calculated error allows PCM to accurately compensate for reference period variations. Crankshaft position system variation learning feature enhances ability of PCM to detect misfire events over a wider range of engine speed and load.

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

DTC P1336 indicates that crankshaft position system variation values have not been stored in PCM and crankshaft position system variation learn procedure must be performed. Procedure is required after 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.