P0189
Fuel Temperature Sensor B Circuit Intermittent
Fuel temperature sensor
Generic OBD-II
Low
What it means
P0189 means the signal from the "B" fuel temperature sensor is cutting in and out or jumping erratically. The ECM uses fuel temperature to fine-tune fueling, so an intermittent signal has little effect on how the car drives. The cause is almost always an intermittent wiring or connector fault or a failing sensor — not something that stops the engine.
Low
Can I keep driving? Generally safe to drive — a fuel-temperature sensor fault won't strand you; the ECM uses a substitute value, with at most minor changes to fueling.
Common symptoms
What you'll notice
- Check-engine light on
- Fluctuating or implausible fuel-temperature readings
- Occasional slightly rough running
- Often no noticeable change in how the car drives
Common causes
Most likely first
- Faulty fuel temperature sensor BLikely
- Intermittent open or short in the sensor wiringCommon
- Loose or corroded sensor connectorCommon
- Rarely, an ECM/PCM faultLess often
How to diagnose & fix
Work through it in order
- Wiggle-test the sensor connector and harness while watching live data for the reading to drop out or spike.
- Inspect the connector for corrosion or spread terminals and reseat it.
- Measure sensor resistance against spec; replace it if the reading is erratic or out of range.
- If wiring and sensor are good, suspect the ECM. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0189?+
Yes, generally. The fuel-temperature reading only fine-tunes fueling, so the engine runs on a fallback value; still fix it to keep fueling accurate.
Can I just clear P0189?+
You can, but an intermittent fault like this typically returns; the real fix is finding the loose connection or replacing the sensor.
Related codes
Often seen with P0189
Read & clear P0189 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX