P0117 Engine coolant temperature sensor 1 circuit low
What P0117 means
The voltage from the coolant temperature sensor is below range, which the engine computer reads as an extremely hot engine. It ignores the sensor, uses a default value and usually runs the cooling fans continuously.
P0117 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
- Cooling fan runs constantly
- Temperature gauge reads high or at maximum
- Hard starting when cold
- Lean running when cold
Common causes
- Internally shorted coolant temperature sensor
- Signal wire shorted to ground
- Damaged or corroded connector
- Coolant contamination in the connector
Can I keep driving with P0117?
You can drive, but have it checked within a week. Replacing the sensor often fixes it, but first make sure the engine is not actually overheating.
What to check first
- Confirm the engine is not really overheating: check coolant level and feel the radiator hoses once safe.
- Read the live coolant temperature; a very high value on a cold engine confirms the circuit fault.
- Unplug the sensor: if the reading drops to a very low value, the sensor is shorted; if it stays high, the wiring is shorted to ground.
- Replace the sensor or repair the wiring.
Related codes
- P0116 Engine coolant temperature sensor 1 range/performance
- P0118 Engine coolant temperature sensor 1 circuit high
- 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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