P25D8Fuel Level Sensor C 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
- P25D8 says that the third fuel level input delivers an electrically valid signal whose behaviour is not believable: it jumps, drifts or disagrees with the fuel actually used or transferred. A sender frozen at one value has its own code, P25DC, so P25D8 covers the remaining plausibility faults. No manufacturer documents P25D8 publicly. Comparable checks exist for the second sender: Ford treats more than 100 changes of over 40 % between samples taken every 0.1 s as a noisy signal (P2066), and GM's 2020 dual-tank logic checks whether the secondary sender reacts when its transfer pump moves fuel. A C-side check would likely follow similar ideas. CARB requires such rationality monitoring for fuel level inputs. The driver may see an erratic gauge or a range estimate that makes no sense.
- What you may notice
- Fuel gauge jumps or shows unrealistic values
- Range estimate inconsistent
- Check engine lamp on after repeated detection
- Likely causes
- LikelyWorn or dirty resistor track in sender C giving jumps
- PossibleTransfer pump or line fault so the level in tank C does not change as expected
- RareDamaged or loose float on sender C
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €100 – €650
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.