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P0115 — Engine Coolant Temperature Sensor 1 Circuit
CautionCoolingLimp to the next safe stop
Seen on: Heavy Truck
Engine Coolant Temperature Sensor 1 Circuit. Common causes: ECT sensor circuit fault.
Don't risk it — get a diesel tech on the truck.
Your code rides along, so nearby mechanics see the fault before they quote you.
How serious is it?
Caution. Limp to the next safe stop.
Most likely causes
- ECT sensor circuit fault
- Failed sensor
- wiring fault
First moves (roadside)
- Measure ECT sensor resistance
- check wiring
- replace sensor
FAQ
What does P0115 mean?
Engine Coolant Temperature Sensor 1 Circuit. Common causes: ECT sensor circuit fault.
How serious is P0115?
Caution — Limp to the next safe stop.
What's the most likely cause of P0115?
The most common cause is: ECT sensor circuit fault. Other possibilities include Failed sensor; wiring fault.
Can I keep driving with P0115?
Limp to the next safe stop. 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.