Severity: Moderate
Drivable, but it can cause more damage or poor economy. Get it checked within days.
What P0118 means
Coolant temperature sensor signal is too high (the computer sees a very cold engine).
Symptoms
- Hard starting when warm
- Poor economy
- Gauge reads cold
Common causes
Most likely first
- 1Open sensor or connector
- 2Broken wire
How we diagnose it
- Check sensor resistance
- Check 5V reference and ground
Every vehicle sets codes under its own conditions. We check the factory diagnostic steps and service bulletins for your VIN, so the repair targets the actual cause.