DTC P0315: Crankshaft Position Sensor Variation Not Learned: Description
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Suburban, and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
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 sensors. The calculated error allows the Powertrain Control Module (PCM) to accurately compensate for reference period variation. This enhances the ability of the PCM to detect misfire events over a wider range of engine speed and load. The PCM stores the CKP system variation values after a learn procedure has been performed. This DTC set indicated that the CKP system variation values have not been stored in the PCM and the CKP system variation learn procedure must be performed.