B1052 — Coolant/Diesel Heater Circuit Fault
Seen on: Heavy Truck
Coolant/Diesel Heater Circuit Fault. Common causes: Cab heater system 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
- Cab heater system fault
- Failed heater unit
- fuel supply issue
First moves (roadside)
- Check heater fuel supply
- inspect heater ignitor and blower
- read heater fault codes
FAQ
Coolant/Diesel Heater Circuit Fault. Common causes: Cab heater system fault.
Serious — Power derate likely — plan to stop soon.
The most common cause is: Cab heater system fault. Other possibilities include Failed heater unit; fuel supply issue.
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.