Circuit 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 wide range of engine speed and load. The PCM stores the Crankshaft Position System Variation values after a learn procedure has been performed. If the actual crankshaft position variation is not within the Crankshaft Position 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, DTC P0315 sets.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0315 Crankshaft Position (CKP) System Variation Not Learned
Conditions for Running the DTC
| • | DTCs P0335, P0336, P0341, P0342, or P0343 are not set. |
| • | DTC P0315 runs every 100 milliseconds. |
Conditions for Setting the DTC
| • | The CKP system variation values are not stored in the PCM memory. |
| • | The enable counter equals 0. |
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records. |
Conditions for Clearing the MIL/DTC
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Step | Action | Yes | No | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |||||||||||||||||||
2 |
Important: The Crankshaft Position Variation Learn Procedure may have to be repeated up to 5 times before the procedure is learned. Perform the Crankshaft Position (CKP) System Variation Learn Procedure. Refer to Crankshaft Position System Variation Learn . Does the scan tool display Learned this ignition? | Go to Step 4 | Go to Step 3 | ||||||||||||||||||
3 | If the CKP system variation learn procedure cannot be performed successfully, check for the following conditions and correct as necessary:
Did you complete the inspection? | Go to Step 4 | -- | ||||||||||||||||||
4 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 5 | ||||||||||||||||||
5 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK |
