P0186 Code: Fuel Temperature Sensor B Range/Performance
🟢 Low severity · drivable
Safe to drive. The fuel temperature reading is unreliable, which may slightly affect cold starts and fuel economy.
What P0186 means
The fuel temperature sensor B is sending a reading that is outside the range the computer expects, or the reading changes too slowly. The sensor may be failing or reading fuel temperature incorrectly. The computer can't fully trust the fuel temperature value it needs for fuel delivery.
Symptoms
- Check engine light is on
- Possible hard cold start
- Slightly worse fuel economy
- Usually no noticeable driving symptoms
Common causes
- most common: Failing fuel temperature sensor B
- common: Damaged wiring or connector at the sensor
- less common: Poor ground connection
- rare: Faulty engine computer (PCM)
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Replace fuel temperature sensor B | Yes | $40–150 |
| Repair or replace damaged wiring and connectors | Yes | $10–60 |
Frequently asked questions
Can I drive with a P0186 code?
Yes. The car is safe to drive, though fuel delivery calculations may be slightly off until it's fixed.
What does "range/performance" mean here?
The fuel temperature reading from sensor B is outside the expected range, or the sensor responds too slowly to real temperature changes.
What is the most common cause of P0186?
A failing fuel temperature sensor B, with wiring problems as the next most likely cause.
Related codes
P0185
P0185 Code: Fuel Temperature Sensor B Circuit Malfunction
P0181P0181 Code: Fuel Temperature Sensor A Range/Performance
P0187P0187 Code: Fuel Temperature Sensor B Circuit Low
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.