OBD-II code · Powertrain (generic)

P034A Crankshaft Position Sensor - Crankshaft Start Position Incorrect

At engine start the crankshaft position reported by the sensor does not match the calibrated start window — typically a wrong tone-wheel installation, sensor air gap, or PCM not synchronised after a relearn.

Is it safe to drive with P034A?

Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.

Common causes

  • Most likelyTone wheel misindexed or relearn pending

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
1–4 h
Emissions test
Likely to fail
Parts involved
Crankshaft Position Sensor, Flywheel

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.