P0315
Crankshaft Position System Variation Not Learned
The engine computer needs to relearn the crankshaft position variation but has not done it yet. This often happens after replacing the crank sensor, PCM, engine, timing parts, or after certain repairs that changed crankshaft or misfire reference data.
- SEV
- 2/5
- DRIVE
- CAUTION
- DIY
- $0-$150
- SHOP
- $100-$300
Quick answer
AI-CITATION READYWhat it means
Can you drive with it?
Most common causes
- Crankshaft variation relearn procedure was not performed after repair
- PCM replaced, reprogrammed, or lost memory
- Crankshaft position sensor replaced or disturbed
Typical repair cost
DIY usually runs $0-$150. Typical shop repair lands around $100-$300, depending on the root cause.
01 / Definition
P0315 means the PCM has not learned the crankshaft position system variation values needed for accurate misfire detection and timing reference. The code usually appears after PCM replacement or programming, crankshaft position sensor replacement, engine replacement, timing chain or flywheel work, or battery and memory loss events on some vehicles. It can also appear if an engine mechanical or sensor fault prevents the relearn from completing.
02 / Drive status
With caution. The vehicle may still run normally, but misfire monitoring and drivability can be affected. Drive with caution and complete the relearn procedure as soon as possible, especially if other crank or cam codes are present.
03 / Symptoms
- Check engine light
- Vehicle may run normally
- Misfire monitor not ready
- Possible hesitation or drivability issue on some vehicles
- Related crankshaft or camshaft sensor codes may also be present
04 / Causes
| 1 | Crankshaft variation relearn procedure was not performed after repair | high |
|---|---|---|
| 2 | PCM replaced, reprogrammed, or lost memory | high |
| 3 | Crankshaft position sensor replaced or disturbed | medium |
| 4 | Engine timing, flywheel, flexplate, harmonic balancer, or reluctor work changed reference values | medium |
| 5 | Crankshaft or camshaft sensor problem preventing relearn | medium |
| 6 | Engine misfire, timing fault, or mechanical problem blocking the procedure | low |
05 / Diagnostic sequence
- 01Check service history for recent PCM programming, crank sensor replacement, engine work, or timing repairs.
- 02Scan for related codes such as P0335, P0340, P0016, P0017, or active misfire codes.
- 03Verify the crankshaft position sensor and its wiring are installed correctly and free of damage.
- 04Confirm battery voltage is stable and no charging system faults are present before attempting relearn.
- 05Make sure the engine is mechanically sound and no active misfire or timing fault would block the relearn procedure.
- 06Perform the manufacturer-specific crankshaft variation relearn with a capable scan tool.
- 07Clear codes and verify the relearn completed successfully and P0315 does not return.
06 / Repairs
| 1 | Perform the crankshaft position variation relearn procedure with a compatible scan tool | $0-$150 |
|---|---|---|
| 2 | Repair crankshaft position sensor wiring or installation issues if relearn will not complete | $20-$200 |
| 3 | Replace a faulty crankshaft position sensor if testing confirms signal problems | $30-$150 |
| 4 | Correct timing, misfire, or mechanical faults blocking the relearn procedure | $100-$1,500+ |
| 5 | Reprogram or diagnose the PCM if memory or calibration problems remain | $100-$300 |
07 / Related codes
08 / FAQ
What does P0315 mean?
It means the PCM has not learned the crankshaft position variation values it needs.
Will P0315 clear itself?
Usually no. The crank variation relearn normally has to be completed with the correct procedure.
Can I drive with P0315?
Often yes, but misfire monitoring may not work correctly and related timing faults should not be ignored.
What repairs commonly trigger P0315?
Crank sensor replacement, PCM programming, engine replacement, timing repairs, and flywheel or reluctor work are common triggers.
09 / Source and method
- DATA BASIS
- OBD-II REFERENCE + OBD2.HELP
- METHOD
- STATIC VALIDATION
- SAFETY
- INFORMATIONAL
This page combines OBD-II diagnostic reference data with OBD2.help generated diagnostic guidance for code meaning, likely causes, and repair direction.
Publishing uses deterministic schema and build validation, plus manual spot checks on representative pages before release.
Safety-critical diagnosis and repairs should be confirmed with a qualified mechanic, especially when the vehicle is misfiring, overheating, or losing power.