P0118 Engine coolant temperature sensor 1 circuit high
What P0118 means
The voltage from the coolant temperature sensor is above range, which the engine computer reads as an extremely cold engine. This usually means an open circuit. The computer uses a default value and often runs the fans as a precaution.
P0118 is a generic SAE J2012 code: it means the same on every make. The exact cause still depends on the car, so read the freeze-frame data before replacing parts.
At a glance
- Severity
- Medium
- Typical repair cost
- 40–180 €
- Workshop time
- 0.3–1.5 h
- Repair difficulty
- Easy
- DIY possible
- Yes
- Check engine light
- Yes
- Affects emissions test
- Yes
Parts and labour at an independent workshop in Europe. Main dealers charge more; the cause decides the bill, not the code.
Symptoms
- Check engine light on
- Temperature gauge stays at minimum
- Cooling fan runs constantly
- Rich running and higher fuel consumption
- Black smoke on diesels
Common causes
- Open circuit in the sensor signal wire or unplugged connector
- Failed coolant temperature sensor
- Poor ground connection in the sensor circuit
- Corroded connector pins
Can I keep driving with P0118?
You can drive, but have it checked within a week. It is usually an inexpensive sensor or connector repair; watch the coolant level in the meantime.
What to check first
- Check that the sensor connector is plugged in and free from corrosion.
- Read the live coolant temperature; around -40 °C indicates an open circuit.
- Bridge the connector pins with the key on: if the reading jumps high, the wiring is good and the sensor has failed.
- Check the ground circuit, then replace the sensor if needed.
Related codes
- P0117 Engine coolant temperature sensor 1 circuit low
- P0116 Engine coolant temperature sensor 1 range/performance
- P0115 Engine coolant temperature sensor 1 circuit
- P0113 Intake air temperature sensor 1 circuit high (bank 1)
- P0112 Intake air temperature sensor 1 circuit low (bank 1)
- P0111 Intake air temperature sensor 1 range/performance (bank 1)
- P0110 Intake air temperature sensor 1 circuit (bank 1)
- P0120 Throttle/pedal position sensor A circuit
Data: TORKO fault-code catalogue, built on OBDex (CC0-1.0) and reviewed against workshop practice. Informational only — it does not replace a diagnosis by a mechanic.
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