P2C42Fan 4 Performance/Stuck Off
- 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
- P2C42 reports that the fourth fan output does not deliver what is asked of it: the fan stays still or reaches far too little speed while its control line shows no electrical fault (those would be P2C3E to P2C40). No manufacturer publicly documents P2C42. Which part is fan 4 varies: a further radiator fan stage, an auxiliary fan for a charge air or oil cooler, or an engine compartment blower like the pair Porsche fits to the rear-engined 911, whose failure brings a warning to avoid full engine load. Mechanical blocking by dirt, as Audi found on the e-tron GT, worn bearings and a failed fan electronics module are the usual causes. Clean and spin the fan by hand before replacing parts. Fan 3 has P2C41, fan 2 P2B31.
- What you may notice
- Temperature warning or reduced power under high load
- Fan 4 does not turn when activated with a scan tool
- Grinding noise before the fan stops
- Likely causes
- LikelyFan jammed by debris or a damaged shroud
- PossibleWorn bearings or corroded motor
- PossibleIntegrated fan electronics or fan module failed
- 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: €80 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.