P0389Crankshaft Position Sensor B Circuit Intermittent
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- Some engines have a second crankshaft sensor or a second track on the tone wheel – GM's 3.4/3.5/3.8-litre V6 use the low resolution track of a dual Hall sensor, the Honda 3.5-litre in the Saturn Vue Redline a second sensor – which the engine module checks against sensor A or the camshaft. By its J2012 name P0389 means the signal of sensor B drops out for moments or becomes erratic – missing or extra edges – without staying permanently low or high. Such faults are typically found by counting pulses against sensor A or the camshaft, as GM's 3.8-litre V6 and the Honda engine do; both, however, report the result under P0385/P0386, and no manufacturer document available to us uses P0389. The description therefore follows the J2012 name, these component sources and CARB. Typical causes are a loose contact, a broken wire and interference.
- What you may notice
- Check engine light on, possibly only after several trips
- Occasional stalling or jerking
- Sporadic starting problems
- Likely causes
- LikelyLoose contact or corrosion at the sensor B connector
- LikelyWire break or chafing that appears with engine movement
- PossibleElectrical interference (add-on devices, routing near ignition or relays)
- PossibleTone wheel damaged or dirty, air gap too large
- PossibleSensor faulty, temperature-dependent
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €40 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.