Circuit/System Description

The crankshaft position (CKP) system variation learn feature is used to calculate reference period errors caused by slight tolerance variations in the crankshaft, and the CKP sensor. The calculated error allows the powertrain control module (PCM) to accurately compensate for reference period variations. This enhances the ability of the PCM to detect misfire events over a wider range of engine speed and load.

The CKP system variation compensating values are stored in PCM memory after a learn procedure has been performed and the ignition switch is turned to the OFF position for at least 30 seconds. If the actual CKP variation is not within the CKP system variation compensating values stored in the PCM, DTC P0300 may set.

If the CKP system variation values are not stored in the PCM memory or a proper PCM power down does not occur after completing the CKP Learn Procedure, DTC P0315 sets.