P0315Generic code

P0315 Code: Crankshaft Position System Variation Not Learned

The P0315 code means the computer has not memorized the small differences in the crankshaft reluctor wheel. Without that learning it cannot watch for misfires properly. It usually appears after a repair, does not change how the car drives, and is fixed with a relearn procedure.

Severity
Low
Can I keep driving?
Yes, no immediate risk
Estimated cost
$0 to $100
Difficulty
Easy
System
Ignition and Misfires
Applies to
All OBD2 vehicles

Updated Reviewed by Renzo Chacca

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What the P0315 code means

Every reluctor wheel has tiny manufacturing differences between its teeth. The computer learns them (CKP variation, crank relearn, or CASE on GM) so it can detect misfires accurately.

After the computer, the crankshaft sensor, the flywheel or the wheel itself is replaced, that learning is erased and the P0315 code appears. It is solved by running the learning procedure, normally with a scan tool.

Until it is done, the computer may disable the misfire monitor, and the vehicle will not pass the emissions inspection.

P0315 code symptoms

  • Check engine light on.
  • Misfire monitor incomplete.
  • Normally no driving symptoms.

Likely causes of the P0315 code

  1. Relearn not performed after the computer, the CKP sensor or the flywheel was replaced.
  2. Relearn interrupted.
  3. Damaged reluctor wheel that prevents the learning from finishing.

How to diagnose the P0315 code step by step

  1. Find out whether there were recent repairs.
  2. Perform the relearn with the scan tool. It usually requires a warm engine and taking it to a specific rpm with your foot on the brake.
  3. If it does not complete, inspect the reluctor wheel and the CKP sensor.

How to fix the P0315 code

  • Perform the crankshaft variation relearn.
  • Repair the reluctor wheel if it is damaged.

After the relearn, clear the code and drive the vehicle through a few normal drive cycles so the misfire monitor can run and reach ready status.

Technical reference data

  • Some manufacturers allow the relearn to be done with decelerations on the road.
  • These values are for orientation only. Check the manufacturer data for your engine.

Brand-specific notes

P0315 on GM

This code is very frequent on GM vehicles, which use the CASE Relearn procedure.

P0315 on Ford

This code is very frequent on Ford vehicles, which use the crankshaft profile learning procedure.

Frequently asked questions about P0315

How is the relearn done?
With a compatible scan tool: warm engine, brake pedal pressed, and accelerate until the fuel cuts off. On some models it is done with decelerations on the road.
Is the P0315 code serious?
The P0315 code does not affect driving, but it leaves misfires unmonitored until the relearn is done.
Can I drive with a P0315 code?
Yes. The engine runs normally, but the vehicle will not pass an emissions inspection until the relearn is done.
How much does it cost to fix P0315?
Between $0 and $100 if it is only the relearn.
What does the P0315 code mean?
It is a generic OBD2 code that means the computer has no stored crankshaft variation values. It usually appears right after a repair that erased the learning.
Will a P0315 code clear itself?
Not until the relearn is done. On some vehicles the relearn can be completed with decelerations on the road, but on most it takes a scan tool.

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Questions about the P0315 code

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