P0540 — Intake Air Heater Circuit Fault
Seen on: Heavy Truck/Diesel
Intake Air Heater Circuit Fault. Common causes: Intake heater circuit fault.
Your code rides along, so nearby mechanics see the fault before they quote you.
How serious is it?
Serious. Power derate likely — plan to stop soon.
Most likely causes
- Intake heater circuit fault
- Failed grid heater
- open circuit
- fuse blown
First moves (roadside)
- Check intake air heater fuses
- test grid heater resistance
- replace if open
FAQ
Intake Air Heater Circuit Fault. Common causes: Intake heater circuit fault.
Serious — Power derate likely — plan to stop soon.
The most common cause is: Intake heater circuit fault. Other possibilities include Failed grid heater; open circuit; fuse blown.
Power derate likely — plan to stop soon. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Find a mechanic or related guides
General diagnostic guidance for diesel engines (Cummins, Detroit, PACCAR, Volvo, Mack and more). Not a substitute for a scan-tool diagnosis on your specific truck.