Radiator Coolant Temperature Sensor Circuit Low
Radiator coolant temperature sensor signal voltage below expected range. 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: Signal wire shorted to ground
- Low likelihood: Connector pins corroded - high contact resistance
- Low likelihood: Harness chafing through insulation
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
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.