Technical Description of OBD-II Trouble Code
The engine is experiencing a variation in the crankshaft position system that has not been learned.
What does that mean?
This particular diagnostic trouble code is applicable to fuel injected engines from various manufacturers since 2003. These manufacturers include Dodge, Chrysler, Ford, Jeep, Mazda, Mitsubishi, Kia, Isuzu, and Hyundai. The code focuses on the relationship between the crankshaft position sensor (CPS) and the engine controller (ECM/PCM). The PCM measures the variation between reference points of the crankshaft position. These measurements are compared to an ideal reference stored in the PCM. If the variation exceeds a calibrated percentage, a fault code is stored. Typically, this code indicates an electrical circuit fault, although mechanical issues can also contribute depending on the vehicle manufacturer.
The troubleshooting steps may vary depending on the vehicle manufacturer and the type of crankshaft position sensor (CPS) and wire colors.
Symptoms
The symptoms associated with a P0315 engine code may include:
Causes
The typical causes for this code to be set are:
Diagnostic Steps and Repair Information
A good starting point is to check for technical service bulletins (TSB) specific to your vehicle. Your issue may be a known problem with a known fix provided by the manufacturer, which can save you time and money during diagnosis.
If you have a scan tool, note all diagnostic trouble codes that are set along with the P0315 code. Next, clear all diagnostic trouble codes and observe if the P0315 code returns. If it does not, then the problem may have been intermittent or the P0315 code may have been a memory code, indicating a past issue.
If the code does return, further inspection is required. Locate the Crankshaft Position Sensor on your specific vehicle and visually inspect the connectors and wiring. Look for any signs of chafing, rubbing, bare wires, burn spots, or melted plastic. Disconnect the connectors and carefully inspect the terminals inside. Check for corrosion, burning, or any abnormal discoloration. Clean the terminals if necessary using electrical contact cleaner or rubbing alcohol. After cleaning, let them air dry and apply dielectric silicone compound to prevent future issues.
Clear the diagnostic trouble codes from memory again and observe if the code returns. If it does not, then the issue was likely related to the connections.
If the code persists, remove the Crankshaft Position Sensor from the engine and inspect it for any damage near the timing components, flex plate, or flywheel. If there is damage, the sensor will need to be replaced. It is recommended to use an OEM or dealer sensor to ensure compatibility with the PCM. While the CPS sensor is removed, inspect the timing components for any issues, such as cracked tone wheel teeth or excessive slack in the timing chain. If unsure, install a new OEM CPS sensor and retest.
If the code still cannot be cleared, check if your scan tool supports Crankshaft Position Relearn. If it does, perform this procedure. Ensure that all codes are cleared prior to performing the relearn procedure. If your scan tool does not support this procedure, seek assistance from a trained automotive diagnostician.
