P25F3Turbocharger/Supercharger Boost Sensor C Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P25F3 means boost sensor C delivers a signal that is electrically valid but does not agree with what the other pressure readings and the engine model suggest. Saab's 2.0 litre turbo engine, developed with GM, shows how this is checked for sensor A: with the engine stopped the reading must lie between 50 and 115 kPa, roughly matching barometric pressure, and while running it is compared with a model built from barometric, manifold and throttle-inlet pressure and throttle position; a failure is a two-trip type B code. A comparable check would apply to C. Typical reasons are a leak or blocked port at the measuring point, oil fouling and sensor drift. No manufacturer publishes this code for sensor C. Expect reduced boost and a lamp.
- What you may notice
- Check engine lamp on
- Reduced power under load
- Hissing noise if a charge air leak is present
- Likely causes
- LikelyCharge air leak near the measuring point of sensor C (hose, clamp, seal)
- PossibleSensor port fouled by oil from crankcase ventilation or a drifting sensor
- RareFaulty barometric or manifold pressure sensor skewing the comparison
- 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: €30 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.