Coolant Thermostat Performance
Thermostat does not regulate coolant temperature in the expected range. Often stuck open (slow warmup) or stuck closed (overheat).
Affected components
- Thermostat
Common causes
- High likelihood: Thermostat stuck
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.