Engine Coolant Level Sensor/Switch Circuit
General electrical fault on the engine coolant level sensor/switch circuit. Many vehicles use a simple float-switch in the expansion tank, others use a continuous-level analog sensor. With the input invalid the ECM cannot warn for low coolant before overheating starts.
Affected components
- Coolant level sensor
- Sensor wiring
Common causes
- High likelihood: Open or shorted wiring to the sensor
- Medium likelihood: Corroded connector at the expansion tank
Diagnostic notes
- The malfunction indicator lamp may illuminate
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.