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B1052 — Coolant/Diesel Heater Circuit Fault
SeriousHVACPower derate likely — plan to stop soon
Seen on: Heavy Truck
Coolant/Diesel Heater Circuit Fault. Common causes: Cab heater system fault.
Don't risk it — get a diesel tech on the truck.
Look up listed providers near you and give them this code when you call.
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
What does B1052 mean?
Coolant/Diesel Heater Circuit Fault. Common causes: Cab heater system fault.
How serious is B1052?
Serious — Power derate likely — plan to stop soon.
What's the most likely cause of B1052?
The most common cause is: Cab heater system fault. Other possibilities include Failed heater unit; fuel supply issue.
Can I keep driving with B1052?
Power derate likely — plan to stop soon. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Throwing this code right now?
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.