P0115 to P0119: engine coolant temperature sensor
The coolant temperature sensor's signal is missing, implausible, too low, too high or intermittent.
SeverityModerateUsually not urgent today, but it can get worse if left.
Can you keep driving?Drive gently, check it soonWhat does P0118 mean?
The coolant temperature sensor is one of the engine computer's most used inputs. It decides the cold start mixture, the idle speed, when the radiator fan runs and often what the dashboard gauge shows. With a faulty signal the computer usually substitutes a default value, which can mean hard starting, a fan that runs all the time, or a fan that does not run when it should.
What causes P0118?
- A coolant temperature sensor that has failed internally
- An unplugged or corroded connector, often after work on the cooling system
- A broken wire or a short in the sensor circuit
- Low coolant leaving the sensor in air, for the range code
What to check first for P0118
- Check the coolant level with the engine cold before anything else
- Compare the scan tool reading with the outside temperature after a night parked
- Watch the temperature gauge and the fan: they should match a warming engine
- Inspect the sensor's plug and wires, then test the sensor's resistance
Can you drive with P0118?
Drive gently to a workshop and watch the temperature gauge closely. If the gauge climbs, the fan stops or steam appears, stop: a bad reading can leave the engine without its cooling fan.
Since May 2018 an engine warning light that stays on is a major defect at the MOT, so the car fails until the fault is fixed.
Codes on this page
- P0115Engine Coolant Temperature Circuit
- P0116Engine Coolant Temperature Circuit Range/Performance
- P0117Engine Coolant Temperature Circuit Low
- P0118Engine Coolant Temperature Circuit High
- P0119Engine Coolant Temperature Circuit Intermittent
Related codes
Checked on · Rafael Soares
These are the generic meanings every manufacturer shares. Each brand adds its own detail, so your car's handbook, its service information and a qualified mechanic have the last word. OdoKeep has no connection with any manufacturer, and the app does not read codes from the car.
