Trouble codes › P0117
P0117 Engine Coolant Temperature Circuit Low
Cooling
P0117 means the coolant temperature sensor reads extremely hot because its signal is shorted low, unless the engine really is overheating.
The coolant temperature sensor's signal voltage is too low, which the engine computer reads as an extremely hot engine. It's usually a shorted sensor or a wire shorted to ground.
Check the actual engine temperature: if it really is overheating, stop. If it's a sensor fault, it may run rich and the fans may run constantly; get it fixed soon.
Common causes
- A shorted coolant temperature sensor
- A signal wire shorted to ground
- A real overheating engine (check before assuming it's the sensor)
Symptoms
- Temperature gauge reading very hot
- Fans running constantly
- Running rich, poor fuel economy
What to check first
- Make sure the engine isn't really overheating: check coolant level and feel the upper radiator hose carefully.
- With a scan tool, check the coolant temperature on a cold engine; a very high reading means a sensor or wiring fault.
- Unplug the sensor: the reading should jump to very cold. If it does, the sensor is shorted; if not, look for a wiring short.
- Replace the sensor if needed.
What does P0117 mean on your vehicle?
The likely cause depends on your engine. iRepair researches your exact year, make, model and engine (service bulletins, recalls and owner reports) and tells you what to check first. Your first 3 questions are free.
Ask iRepair about P0117No scanner? Most auto parts stores read check-engine codes for free.
Related codes
General guidance for P0117 on most vehicles. Some makers use the same code a little differently; confirm in the service information for your vehicle, put safety first, and see a professional when in doubt.