When it comes to GMC vehicles, the P0315 code is an important one to recognize. The GMC P0315 code stands for Crankshaft Position System Variation Not Learned, and it is a code set when the engine speed is between 900-1,900 RPM and the ECM is in fuel shut-off or decel fuel cut-off mode. The Diagnostic Trouble Code (DTCs) P0016, P0335, P0336, P0340, and P0341 are not set, and the ECM detects that the Crankshaft Position Reluctor Wheel Learn values are not stored in memory for an accumulated time of more than 84 minutes. As a result, the diagnostic runs continuously when these conditions are met. Fortunately, several related service bulletins can help diagnose and fix the problem.
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Causes and Solutions for GMC P0315 Code
| Causes | Solutions |
|---|---|
| Engine speed is between 900-1,900 RPM | Check the engine speed and adjust accordingly |
| The ECM is in fuel shut-off or decel fuel cut-off mode | Check the ECM and make sure it is in the correct mode |
| The Crankshaft Position, Reluctor Wheel Learn, has not been learned successfully | Check the Reluctor Wheel and adjust it if necessary |
| The ECM detects that the Crankshaft Position Reluctor Wheel Learn values are not stored in memory for more than 84 minutes. | Replace the ECM if necessary and reset the values |
Engine Speed
The GMC P0315 code is triggered when the engine speed is between 900-1,900 RPM and the ECM is in fuel shut-off or decel fuel cut-off mode. To ensure that the engine speed is within the acceptable range, the engine should be checked and adjusted accordingly.
ECM Mode
The ECM should also be checked to ensure it is in the correct mode. If the ECM is in fuel shut-off or decel fuel cut-off mode, it can cause the P0315 code to be set. The ECM should be reset if necessary to ensure that it is correct.
Crankshaft Position Reluctor Wheel Learn
If the Crankshaft Position Reluctor Wheel Learn values are not stored in memory for more than 84 minutes, the P0315 code will be set. In this case, the Reluctor Wheel should be checked and adjusted if necessary. Additionally, the ECM should be replaced, and the values reset if necessary.
Service Bulletins
Fortunately, several related service bulletins can help diagnose and fix the problem. These can be used to ensure that the issue is properly diagnosed and resolved.
Conclusion
The GMC P0315 code stands for Crankshaft Position System Variation Not Learned and is triggered when the engine speed is between 900-1,900 RPM and the ECM is in fuel shut-off or decel fuel cut-off mode. To fix the issue, the engine speed should be checked and adjusted accordingly, the ECM should be checked and reset, and the Crankshaft Position Reluctor Wheel Learn should be checked and adjusted if necessary. Additionally, related service bulletins can be used to ensure that the issue is properly diagnosed and resolved. By following these steps, the GMC P0315 Code can be fixed quickly and effectively.