Radiator Coolant Temperature Sensor Circuit Intermittent/Erratic
Intermittent signal from radiator coolant temperature sensor. The engine coolant temperature sensor feeds warm-up enrichment, fan control and closed-loop entry — a stuck-cold reading keeps the engine in open loop and rich forever.
Affected components
- Radiator coolant temp sensor
- Sensor wiring
Common causes
- High likelihood: Connector loose or corroded
- Low likelihood: Connector with intermittent contact under vibration
- Low likelihood: Harness routed against vibrating component
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.