P2CE4Intake Air Heater C Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2CE4 is stored when heater C's circuit shows an excessive signal, typically a short to battery voltage on the control line or a relay that remains switched on. Volvo and Mack document it as P2CE4-12, the suffix standing for a short to battery. It appears in their pre-heat relay instructions for Volvo VN/VNL/VNR/VNX/VHD and Mack Anthem, Granite, Pinnacle and other models from 2014, where technicians first check terminal tension at element and relay and the EMS software, then fit a new relay, supply cable and an updated two-point bracket (2022 version). A heater stuck on can flatten the batteries and overheat the cable, so this fault deserves quick attention. P2CE3 is the low-side code, P2CE1 the open circuit; heater A and B use P0542 and P2608.
- What you may notice
- Batteries drained after the truck has been parked
- Hot or discoloured cable near the heater
- Warning lamp and possibly hard starting if the heater no longer switches
- Likely causes
- LikelyPre-heat relay contacts welded or stuck closed
- PossibleControl line of heater C shorted to a battery-voltage wire
- PossibleFaulty supply power cable or loose bracket mounting affecting the circuit
- RareEngine control module output stage for the relay faulty
- 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 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.