What this code means
P0315 may mean the engine control module does not have the crankshaft position variation learn value stored.
What the vehicle may do
- The vehicle may still run normally.
- Misfire detection accuracy can be affected because the ECM may not have the learned crankshaft variation value available.
- The code may return if the learn has not completed or has not been retained.
Possible fault areas
- Possible incomplete crankshaft position variation learn.
- Possible battery condition concern during the learn process.
- Possible service, setup, or control module memory-related concern.
Diagnostic path
Open on what P0315 means
On this Silverado 2500 with the 6.6 L diesel, P0315 means the engine control module does not have the crankshaft position variation learned. That learn value is used to compensate for small crankshaft and crankshaft position sensor variation, so the ECM can better recognize misfire behavior across different engine speeds and loads. The truck may still run, but this code points you toward a possible incomplete crank variation learn, battery condition issue, service or setup issue, or an ECM memory-side problem. The key is not to start guessing at parts. Run the learn path in order and verify whether the code stays gone.
Start with the basic checks
Before using the P0315 path, start with the basic system checks. If other codes are present, check what they mean first, and follow a structured diagnostic approach instead of jumping straight to the learn. Also make sure the battery has passed a load test and is completely charged, because this procedure depends on stable battery condition.
Understand the monitor gate
For this code, the monitor is looking at whether the crankshaft position variation learn has been completed. The engine has to be running, and once the running condition is met, the code can run continuously. The setting logic is simple: crankshaft position variation learn is not learned.
Perform the learn
With the ignition on and the vehicle in service mode, use the scan tool and perform the crankshaft position variation learn. This is the core action for P0315 before moving into the verification step.
Verify after the learn
After the learn, operate the vehicle within the conditions that run the code. If you have captured operating data from when the code set, reproduce those captured conditions as closely as practical. Then verify that P0315 does not reset. If the code does not set, the path is all OK.
If P0315 resets
If P0315 sets again after the learn and verification, this diagnostic path identifies the K20 Engine Control Module as the component to replace. Once the repair is complete, keep verification separate: run the repair verification and confirm the code stays gone.
Takeaway
The takeaway for P0315 is straightforward: confirm the basic checks and battery condition, perform the crankshaft position variation learn, then reproduce the operating conditions and verify the code does not return. For more diagnostic training, visit stepdiagnostics.com.
Final check
This diagnosis is mainly about confirming the learn status, completing the learn correctly, and verifying that P0315 stays gone.
For more guided automotive diagnostics, visit STEP Diagnostics.
