OBD-II code · Powertrain (generic)
P0391 Camshaft Position Sensor B Circuit Range/Performance (Bank 2)
Cam sensor B on bank 2 reads in range but plausibility check fails — slow response, drift, or signal does not match expected cam profile.
Is it safe to drive with P0391?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor drift
- Less likelySensor element aged beyond calibration window
- Less likelySensor mounting loose - signal damping
Symptoms
- Check engine light on
- Power loss especially in mid-rpm range
- Possible rough idle or stalling
- Increased fuel consumption
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2.5 h
- Emissions test
- Likely to fail
- Parts involved
- Camshaft Position Sensor
Related codes
- P0366Camshaft Position Sensor B Circuit Range/Performance (Bank 1)
- P0390Camshaft Position Sensor B Circuit (Bank 2)
- P038EIgnition J Control Signal Circuit Low
- P038FIgnition J Control Signal Circuit High
- P0392Camshaft Position Sensor B Circuit Low (Bank 2)
- P0393Camshaft Position Sensor B Circuit High (Bank 2)
- P0394Camshaft Position Sensor B Circuit Intermittent (Bank 2)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.