P0315

Crankshaft Position System Variation Not Learned

Crankshaft position Generic OBD-II High

What it means

P0315 means the ECM has not stored the crankshaft-position variation values it needs to run its misfire monitor accurately. This relearn is normally performed with a scan tool after a battery, ECM, or crankshaft-sensor service. The engine usually runs fine — the ECM just can't reliably watch for misfires until the variation table is learned.

High

Can I keep driving? Usually driveable and runs normally — this code mainly means the crankshaft variation relearn wasn't completed, which disables misfire detection until it's done.

Real-world scan data

Seen in

456

scans in the past year

Found in

0.1%

of scans

0.1%

of scans that found faults

Appears alongside · share of P0315 scans

P0300in 41.2% of scans

P0420in 36.8% of scans

P0335in 36.0% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Often no noticeable change in how the car drives
Misfire monitor disabled (other misfire codes may not set)
Rough running only if an underlying crank-sensor fault exists

Common causes

Most likely first

Crankshaft variation relearn procedure not performed after serviceLikely
Incorrectly installed or faulty crankshaft position sensorCommon
Damaged reluctor / tone ring on the crankshaftCommon
Wiring or connector fault in the CKP circuitLess often
Low battery voltage during the relearn attemptLess often

How to diagnose & fix

Work through it in order

Perform the crankshaft-position variation relearn with a capable scan tool — this alone often clears it.
Confirm battery voltage is good before and during the relearn.
Inspect the crankshaft position sensor installation and connector.
Check the reluctor ring for damage or debris.
If the relearn won't complete, diagnose the CKP sensor and wiring. Clear and re-test.

FAQ

Quick answers

Is it safe to drive with P0315?+

Generally yes — the engine runs normally, but with misfire detection off you could miss a developing problem, so complete the relearn.

Can I just clear P0315?+

Clearing without doing the relearn won't help; the code returns until the variation procedure is completed.

Read & clear P0315 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX