The crankshaft position system variation learning feature calculates the reference period errors that are caused by slight tolerance variations in the crankshaft, the crankshaft balancer interrupter rings, and the crankshaft position sensor hall effect switches. The calculated error allows the PCM
to accurately compensate for reference period variations. This enhances the ability of the PCM
to detect misfire events during a wider range of engine speed and load conditions.
The crankshaft position system variation values are stored in the PCM
non-volatile memory after a learn procedure has been performed. If the crankshaft position system variation values are not stored in the PCM
, DTC P1336 will set. The learn procedure is required after the following service procedures have been performed:
Crankshaft balancer replacement
Crankshaft position sensor replacement
Any engine repair which disturbs the crankshaft or the harmonic balancer to crankshaft position sensor relationship.