Powertrain
generic / SAE
P0117
Engine Coolant Temperature Sensor Low Input
The ECT signal voltage is below threshold, which the ECU interprets as an implausibly hot coolant temperature (typical NTC sensor characteristic — low resistance at high temperature).
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number1 / 17
Possible causes
- Signal wire shorted to ground high
- Sensor failed shorted internally medium
Symptoms
- Check engine light on
- Cooling fan runs constantly or not at all
- Cabin heater weak or excessively hot
- Possible long warm-up time or hard cold start
Inspection / repair
- Difficulty: easy
- DIY: possible
- Estimated cost: 30–200 €
- Estimated time: 0.3–1.5 h
- Component: coolant temperature sensor
- Component: coolant temperature sensor wiring
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012