P0315 code meaning
Crankshaft Position System Variation Not Learned
Powertrain system Generic code P03xx codes Check engine light
What P0315 means
Manufacturing tolerances of the crankshaft tone wheel distort the speed fluctuations misfire detection relies on, so the engine module learns a correction for each tooth or segment. P0315 means these values have not been learned or are invalid. GM checks that the learned tooth angles add up to 360° (deviation above 0.001° sets the code in the first trip) and learns them with a scan tool: brakes held, full throttle in park until fuel cut-off. Ford learns the profile during up to three overrun phases from 60 to 40 mph and sets P0315 when that fails. Until relearned, misfire detection is suspended – at GM above 1,000 rpm – and misfire readiness stays incomplete. The relearn is needed after replacing the engine, engine module, crankshaft, damper or crankshaft sensor.
P0315 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.3 to 1 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0315
- Check engine light on (GM; Ford depending on application)
- Driving usually unaffected
- Misfire readiness not set – emissions test fails
Common causes of P0315
- Most likelyRelearn not performed after replacing sensor, crankshaft, damper, engine or engine module
- PossibleLearned values lost through voltage loss (battery disconnected)
- PossibleTone wheel damaged or shifted, crankshaft runout, dirt on the sensor
- Less likelyInterference in the crankshaft sensor circuit
- Less likelyEngine module memory faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Crankshaft position sensorCrankshaft tone wheelEngine control module
What each part of P0315 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 3 | Area: ignition system or misfire. |
| 15 | The exact fault in that area. |
What to do next
- Note P0315 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0315
What does P0315 mean?
P0315 means "Crankshaft Position System Variation Not Learned". Manufacturing tolerances of the crankshaft tone wheel distort the speed fluctuations misfire detection relies on, so the engine module learns a correction for each tooth or segment. It is a generic code, so it means the same on every make.
Is it safe to drive with P0315?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P0315 fail an emissions test?
Yes, it can. P0315 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0315 to fix?
Difficulty: medium. A typical repair takes 0.3 to 1 hours of work. This is a job for a workshop.
Will P0315 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.