B1052 — Coolant/Diesel Heater Circuit Fault
What it means: Coolant/Diesel Heater Circuit Fault.
How serious / can you keep driving: Serious. Power derate likely — plan to stop soon.
Check first: Check heater fuel supply
Don't risk it — look up listed providers near you and give them this code when you call.
Listed providers nearest Sparks, NV
Closest first. Tell them B1052 and what the truck is doing. RoadService.app lists these providers and does not employ them or carry out the repair.
- 0.0 mi away — based in Sparks, NV · (775) 355-6884
- 0.0 mi away — based in Sparks, NV · (775) 356-7200
- 0.0 mi away — based in Sparks, NV · (775) 359-0550
Seen on: Heavy Truck
What B1052 means
Coolant/Diesel Heater Circuit Fault. Common causes: Cab heater system fault.
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.
Related codes
Codes that commonly appear alongside B1052, or share the same subsystem.
- Blower Motor Circuit Open (B1004)
- Blower Motor Circuit Short to Ground (B1005)
- APU HVAC Communication Fault (B1050)
- HVAC Control Module Voltage High (B1001)
- HVAC Control Module Voltage Low (B1002)
- A/C Pressure Sensor Circuit Fault (B1010)
- Air Distribution Actuator Fault (B1040)
- Temperature Blend Door Actuator Fault (B1041)
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.