P2066
Fuel Level Sensor B Performance
Fuel level sensing
Generic OBD-II
Low
What it means
P2066 means the second fuel level sensor is not reading plausibly — its signal does not track the fuel in the tank as expected. Many vehicles use two senders in a saddle tank, and this code points to the "B" one. The engine runs fine; the main effect is an inaccurate fuel gauge. Check the sending unit and its wiring before replacing parts.
Low
Can I keep driving? Safe to drive — the engine runs normally, but the fuel gauge may read inaccurately, so track your mileage to avoid running out.
Common symptoms
What you'll notice
- Inaccurate, stuck, or erratic fuel gauge reading
- Check-engine light on
- Fuel-remaining or range display may be wrong
- May block the EVAP readiness monitor from completing
Common causes
Most likely first
- Faulty fuel level sensor B (sending unit / float)Likely
- Sensor harness open or shortedCommon
- Poor or corroded electrical connection at the senderCommon
- Faulty instrument cluster / combination meterLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and watch the fuel level signal change as fuel is used or added.
- Inspect the wiring and connector to the sending unit for opens, shorts, or corrosion.
- Test the sending unit's resistance across empty-to-full travel; replace if it reads erratically or out of range.
- If the sender is good, check the instrument cluster/gauge circuit.
FAQ
Quick answers
Is it safe to drive with P2066?+
Yes. The only real risk is an unreliable fuel gauge, so keep an eye on your trip odometer so you do not unexpectedly run out of fuel.
Can I just clear P2066?+
It will return until the sending unit or wiring is repaired, because the gauge signal stays faulty.
Related codes
Often seen with P2066
Read & clear P2066 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