P00F3Humidity Sensor Circuit Range/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
- The humidity sensor measures the relative humidity of the intake air; on documented vehicles it is built into the mass air flow sensor or a combined sensor. The engine control module uses the value, for example, to correct torque and in emission models. One documented design is capacitive and reports humidity as a pulsed signal with a duty cycle that the control module converts back. P00F3 is a plausibility fault: the reading is electrically valid but implausible. One manufacturer documents it being set shortly after starting in heat and extremely dry air; if the live value shows an implausibly low humidity, the air flow sensor with the integrated humidity sensor should be replaced, otherwise the fault is treated as intermittent.
- What you may notice
- Check engine light on
- Usually no noticeable symptoms
- Slightly uneven torque or higher consumption possible
- Likely causes
- LikelyHumidity sensor or combined air flow sensor faulty
- PossibleExtremely dry and hot air making the test borderline
- RareContamination or oil mist on the sensing element
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €80 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.