P2C42 code meaning
Fan 4 Performance/Stuck Off
Powertrain system Generic code P2Cxx codes Check engine light
What P2C42 means
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.
P2C42 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P2C42
- 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
Common causes of P2C42
- Most likelyFan jammed by debris or a damaged shroud
- PossibleWorn bearings or corroded motor
- PossibleIntegrated fan electronics or fan module failed
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Cooling fan 4Fan relay 4ECM
What each part of P2C42 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| C | Area: hybrid propulsion. |
| 42 | The exact fault in that area. |
What to do next
- Note P2C42 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2C42
What does P2C42 mean?
P2C42 means "Fan 4 Performance/Stuck Off". 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). It is a generic code, so it means the same on every make.
Is it safe to drive with P2C42?
Drive gently and only to a workshop. With P2C42 the car can go into limp mode (reduced power) to protect itself.
Will P2C42 fail an emissions test?
Yes, it can. P2C42 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2C42 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2C42 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.