OBD-II code · Powertrain (generic)
P034B Crankshaft Position Sensor - Crankshaft Direction Incorrect
The crankshaft is rotating in the wrong direction relative to the expected reference — typically only seen on stop-start systems where the engine briefly counter-rotates after shutdown.
Is it safe to drive with P034B?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyStop-start residual reverse rotation
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–3 h
- Emissions test
- Likely to fail
- Parts involved
- Crankshaft Position Sensor
Related codes
- P0348Camshaft Position Sensor A Circuit High (Bank 2)
- P0349Camshaft Position Sensor A Circuit Intermittent (Bank 2)
- P034ACrankshaft Position Sensor - Crankshaft Start Position Incorrect
- P034CIon Sense System Performance
- P0350Ignition Coil Primary/Secondary Circuit/Open
- P0351Ignition Coil "A" Primary/Secondary Circuit Malfunction (Cylinder 1)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.