What Does This Mean?
The generic diagnostic code P0315 is related to the powertrain and applies to fuel-injected engines from most manufacturers since 2003.
This code concerns the relationship between the crankshaft position sensor (CPS) and the engine control module (ECM/PCM). The PCM compares the crankshaft position measurements to an ideal reference. If the variation exceeds a certain threshold, an error code is recorded. This issue can be electrical or mechanical in origin.
Affected Manufacturers:
- Dodge, Chrysler, Ford, Jeep, Mazda, Mitsubishi, Kia, Isuzu, Hyundai, etc.
Symptoms
An engine code P0315 can cause:
- Check Engine Light (MIL) illuminated
- Misfires, engine hesitation, or RPM fluctuations
- Engine stalling with possible restart
- Difficulty starting after the engine is turned off
- Engine starts but does not maintain idle
Possible Causes
The most common causes of code P0315 are:
- Crankshaft position relearn not performed or incorrectly executed (most common cause)
- Wear in timing components (chain, gears, distributor, flex plate)
- Faulty crankshaft position sensor
- Issue in the CPS sensor electrical circuit
- Open power or ground circuit
- Faulty signal circuit between the CPS sensor and PCM
- PCM failure (rare)
Diagnostic and Repair Steps
1. Check Technical Service Bulletins (TSB)
Consult technical service bulletins specific to your vehicle. Some models may have known issues with available fixes.
2. Reading and Clearing Error Codes
- Use a diagnostic tool to retrieve all stored codes.
- Clear the codes and restart the engine.
- If the code does not return, it was likely a temporary issue.
- If the code reappears immediately or during a road test, continue diagnostics.
3. Inspect CPS Sensor and Wiring
- Locate the CPS sensor and inspect the connector and wiring.
- Look for signs of damage: exposed wires, burns, corrosion.
- Clean the connectors with electrical contact cleaner.
4. Checking the CPS Sensor
- Remove the sensor and inspect its tip for any damage.
- If the sensor is damaged, replace it with an original equipment (OEM) part.
- Check inside the sensor housing and examine the tone wheel for cracks or damaged teeth.
5. Testing the Timing System
- Manually rotate the engine and observe play in the timing chain.
- If irregularities are found, consider replacing worn components.
6. CPS Sensor Relearn
- Some diagnostic tools allow performing a CPS sensor relearn.
- Before this procedure, ensure all error codes have been cleared.
7. Last Resort: Consult a Professional
If the problem persists despite these checks, it is advisable to consult a qualified technician.