P0127Intake Air Temperature Too High
- 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
- P0127 is not a circuit fault but a functional check of the air path: the measured intake air temperature is too high for the operating state. The logic is documented for a Bosch EDC16 diesel (Saab 9-3): if the intake air exceeds 130 °C and does not fall below it within 45 s after the exhaust gas recirculation valve is closed, hot exhaust gas is evidently still entering or the sensor is wrong. The engine then disables EGR and runs in limp mode with reduced torque. GM has the code in its diesel software but disabled for US OBD II; Ford reports an overly hot intake air reading as P0111 instead. On other engines a hot reading can also come from warm under-bonnet air being drawn in.
- What you may notice
- Check engine light on
- Loss of power, limp mode with torque limit
- EGR switched off
- Knock tendency and retarded ignition on petrol engines
- Likely causes
- LikelyEGR valve stuck open or not sealing (diesel)
- PossibleEGR cooler clogged or bypass flap stuck in bypass
- PossibleCharge air cooler dirty or airflow through it blocked
- PossibleSensor reading wrong, or hot engine-bay air drawn in (loose intake duct)
- 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: €50 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.