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Home >> Chevrolet >> 2004 >> Optra5 Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - 1.4L DOHC - DTC P0336 To DTC P1385 >> DTC P1320 >> Circuit Description

Circuit Description

IMPORTANT: The engine control module (ECM) continuously learns the crankshaft position (CKP) system variations. A CKP variation learn procedure cannot be performed with a scan tool.

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 reluctor wheel. 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 ECM continuously learns the CKP system variation values. If the actual CKP variation is not within the CKP system variation compensating values stored in the ECM, this DTC sets.

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