P2066Fuel Level Sensor B Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2066 flags a second fuel level sender whose reading is electrically valid but does not behave like real fuel. Makers test it differently. GM, on dual-tank trucks with an electric transfer pump, calls it Fuel Level Sensor 2 Performance and looks for a secondary reading that stays frozen while the engine burns 18 L or more, or that barely moves while the pump transfers fuel; Type B, two trips. Ford instead files a noisy signal here: more than 100 jumps of over 40 % between samples taken every 0.1 s, while a stuck sender B gets P25B1. Genesis compares calculated fuel use with the change the sender reports and revised that logic for the 2025 GV80 (25-01-026G). Jeep released PCM flashes for P2066 on 2021–2024 Grand Cherokee models, one symptom being a MIL after refuelling with the engine running. Mercedes uses P206600/P206609.
- What you may notice
- Fuel gauge stays put or lags behind real consumption
- MIL after refuelling or long drives
- Range display and low fuel warning unreliable
- Likely causes
- LikelyFloat arm sticking or sender card worn in one spot
- PossibleTransfer or jet pump not moving fuel between tank halves
- PossiblePlausibility logic needing a software update (Jeep, Genesis)
- RarePoor contact causing a noisy signal (Ford definition)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €0 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.