P0315
Crankshaft Position System Variation Not Learned
- Severity
- Low
- Driving
- Drivable — book it in
The crankshaft position variation relearn procedure has not been completed. This is a calibration, not a fault: every crankshaft and reluctor ring has tiny manufacturing variations, and the module has to measure them before it can tell a genuine misfire from normal irregularity. Until the relearn is done, misfire detection does not work properly.
Possible causes
- CommonRelearn never performed after a crankshaft sensor replacement
- CommonRelearn never performed after control module replacement or reprogramming
- CommonRelearn never performed after engine or timing work
- CommonRelearn attempted but the required conditions were never met
- PossibleAnother stored fault preventing the procedure from completing
What you might notice
- Check engine light on
- Misfire codes that do not match how the engine feels
- Misfire detection not working
- Often no symptom the driver notices
What to check, in order
- Ask what was done recently. A crankshaft sensor, engine or module repair immediately before this appeared is the explanation.
- Run the relearn procedure. It usually requires a specific set of conditions - a warm engine, and a controlled deceleration in gear - and it must be allowed to finish.
- Clear any other stored faults first. The procedure will not complete while another fault is active.
- Do not replace parts for this code. Nothing has failed; a calibration is missing.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Ignition system or misfire
P0300P0301P0302P0303P0304P0305P0306P0307P0308P0309P0310P0311P0312P0313P0314P0315P0316P0317P0318P0319P0320P0321P0322P0323P0324P0325P0326P0327P0328P0329P0330P0331P0332P0333P0334P0335P0336P0337P0338P0339P0340P0341P0342P0343P0344P0345P0346P0347P0348P0349P0350P0351P0352P0353P0354P0355P0356P0357P0358P0359P0360P0361P0362P0363P0364P0365P0366P0367P0368P0369P0370P0371P0372P0373P0374P0375P0376P0377P0378P0379P0380P0381P0382P0383P0384P0385P0386P0387P0388P0389P0390P0391P0392P0393P0394