P0389 — Crankshaft Position Sensor B Circuit High Input
Drive with caution — fix soon.
What P0389 means
This code means the engine computer is seeing a higher-than-expected voltage on the 'B' crankshaft position sensor circuit, which tracks engine speed and crank position. It often points to a wiring problem like a short to power, a bad connector, or a failing sensor. It's usually fixable by repairing the wiring or replacing the sensor, and is not normally a major engine repair.
Common symptoms
- Check engine light is on
- Engine cranks but is hard to start or won't start
- Engine stalls or cuts out unexpectedly
- Hesitation or stumbling while accelerating
- Tachometer reads erratically or drops to zero
Common causes
- Faulty crankshaft position sensor
- Short to voltage in the sensor wiring
- Corroded or loose sensor connector
- Damaged or chafed wiring harness
- Poor ground or reference voltage issue
Typical repair cost
$120 – $400
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0389 code?
For short trips usually yes, but you shouldn't rely on it. Because this sensor controls spark and fuel timing, the engine can stall or refuse to restart without warning. Get it diagnosed soon to avoid being stranded.
How much does it cost to fix a P0389 code?
Most repairs run between $120 and $400. A simple wiring or connector fix is on the low end, while replacing the crankshaft position sensor including labor lands toward the higher end.
Is a P0389 code serious?
It's moderate. The car often still runs, but the fault can cause stalling and no-start conditions, so it shouldn't be ignored. Prompt diagnosis keeps a minor issue from leaving you on the side of the road.
What does the 'B' sensor in P0389 mean?
Some engines use two crankshaft position sensors, and 'B' refers to the second one. The 'high input' part means the computer is reading too much voltage on that circuit, usually from a wiring short or a failing sensor.