P0116 Engine Coolant Temperature Circuit Range/Performance
The coolant temperature reading changes in a way that does not make sense.
Common causes
- Thermostat stuck open
- Faulty ECT sensor
- Low coolant
Symptoms
- Check engine light
- Slow warm-up
- Weak cabin heat
What to check
- Watch warm-up curve on a scan tool
- Check thermostat operation
- Check coolant level
Manufacturers may add their own detail to generic codes. If your vehicle shows a different description for P0116, follow the service information for that make and model.