Insufficient Coolant Temperature for Closed Loop Fuel Control
The engine has run long enough that closed-loop fuel control should be active, but the coolant temperature has not risen high enough. Often caused by a stuck-open thermostat or a failed coolant temperature sensor.
Affected components
- Thermostat
- Coolant temperature sensor
Common causes
- High likelihood: Thermostat stuck open
- Medium likelihood: Coolant temp sensor reading low
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.