P0185
Fuel Temperature Sensor B Circuit
Fuel temperature sensor
Generic OBD-II
Low
What it means
P0185 means the ECM has detected a fault in the "B" fuel temperature sensor circuit. This sensor reports fuel temperature so the ECM can fine-tune fuel delivery — it's most common on diesel and flex-fuel systems. A circuit fault here has only a minor effect on fueling and economy and does not stop the engine from running or starting.
Low
Can I keep driving? Yes — this is a fuel-temperature sensor circuit fault; the engine runs and starts, though economy and cold starting can suffer slightly until repaired.
Common symptoms
What you'll notice
- Check-engine light on
- Minor drop in fuel economy
- Slight change in performance or cold-start behaviour
- Little to no everyday drivability change on many vehicles
Common causes
Most likely first
- Faulty fuel temperature sensor 'B'Likely
- Open or shorted wiring in the sensor circuitCommon
- Corroded or loose sensor connectorCommon
- Failed ECM/PCM (rare)Less often
How to diagnose & fix
Work through it in order
- Read the fuel temperature sensor 'B' value on a scan tool and compare it to actual fuel/ambient temperature.
- Inspect the sensor connector and wiring for damage, corrosion, or a loose pin.
- Back-probe the circuit for opens or shorts against spec.
- Replace the fuel temperature sensor if it reads out of range. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0185?+
Yes. The fuel temperature sensor only fine-tunes fueling, so the engine runs and starts. Expect at most minor economy or cold-start effects until it's repaired.
Can I just clear P0185?+
It will return once the ECM rechecks the circuit and sees the same fault. Repair the sensor or wiring first.
Related codes
Often seen with P0185
Read & clear P0185 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