P0315

DTC P0315

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provide an overview of each diagnostic category.

DTC Descriptor

DTC P0315
- Crankshaft Position (CKP) System Variation Not Learned

Circuit/System Description

The crankshaft position (CKP) system variation learn feature is used to calculate reference period errors caused by slight build tolerance variation in the CKP sensor, crankshaft, and CKP sensor position. 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 wide range of engine speeds and load conditions. The ECM stores the Crankshaft Position System Variations values after a learn procedure has been performed. If the actual crankshaft position variation is not stored within the CKP compensating value look up table, then DTC P0300 may set. If the CKP system variation values are not stored in the ECM memory, or a proper ECM power down does not occur after completing the CKP Learn Procedure, then DTC P0315 sets.

Conditions for Running the DTC

The diagnostic runs continuously.

Conditions for Setting the DTC

The ECM detects that the CKP system variation values are not stored in memory.

Action Taken When the DTC Sets

DTC P0315 is a Type A code.

Conditions for Clearing the DTC

DTC P0315 is a Type A code.

Diagnostic Aids

This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test. Battery Inspection/Test

Circuit/System Testing

Important: The CKP System Variation Learn Procedure may have to be repeated up to 5 times before the procedure is learned.

Perform the CKP System Variation Learn Procedure. Refer to Crankshaft Position System Variation Learn. The scan tool should display Learned this Ignition. Service and Repair

If the CKP System Variation Learn Procedure cannot be performed successfully, inspect for the following conditions:

* Any worn crankshaft main bearings
* A damaged or misaligned reluctor wheel
* Excessive crankshaft runout
* A damaged crankshaft-Refer to Crankshaft and Bearing Cleaning and Inspection.
* Interference in the signal circuit of the CKP sensor
* The ignition switch is left in the ON position, until the battery is discharged.
* An ECM power disconnect, with the ignition ON, that may have erased the CKP system variation values and set DTC P0315
* Any debris between the CKP sensor and the reluctor wheel
* An internal ECM condition that is unable to complete the learn procedure, which will require an ECM replacement

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests