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 crankshaft position sensor. The calculated error allows the engine control module (ECM) to accurately compensate for reference period variations. This enhances the ability of the ECM to detect misfire events over a wider range of engine speed and load.

The CKP system variation compensating values are stored in ECM memory after a learn procedure has been performed. If the actual CKP variation is not within the CKP system variation compensating values stored in the ECM, DTC P0300 may set.

The ECM detects an incorrect CKP system variation values during deceleration or fuel cut-off.

DTC P1320 is a Type B DTC.

DTC P1320 is a Type B DTC.

Scan Tool Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Important: The ECM continuously learns the CKP system variations. A CKP variation learn procedure cannot be performed with a scan tool.

1. If the scan tool displays NOT learned this ignition, inspect for the following conditions:

•	A worn or damaged crankshaft or crankshaft bearings

•	Debris between the CKP sensor and the reluctor wheel

•	A damaged reluctor wheel

•	Excessive crankshaft runout

•	Any interference of the CKP sensor or CKP sensor signal to the control module

2. If the control module is unable to complete the learn procedure, replace the control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming