OBD-II code · Powertrain (generic)
P0388 Crankshaft Position Sensor B Circuit High
Crank sensor B above upper plausibility — open signal or short to B+. The crankshaft position sensor provides RPM and crank angle — without a valid signal, no ignition and no injection. Engine will not start or stalls instantly.
Is it safe to drive with P0388?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen signal line
- Less likelyConnector pins corroded - high contact resistance
- Less likelySupply wire pinched against B+ source
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
- Crankshaft Position Sensor
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.