Water Temperature Sensor

Water Temperature Sensor

The water temperature sensor is typically installed at the engine coolant outlet to monitor the coolant temperature. Most sensors are Negative Temperature Coefficient (NTC) thermistors, where resistance decreases as the temperature rises. Based on this resistance change, the Electronic Control Unit (ECU) determines the engine coolant temperature, using it as a key correction parameter for fuel injection and ignition timing.

Functions: The sensor converts the engine coolant temperature into an electrical signal sent to the ECU to:

1. Adjust fuel injection volume: Increases fuel delivery at low engine temperatures.

2. Adjust ignition advance angle: Advances ignition timing at low temperatures, and retards it at high temperatures to prevent engine knocking.

3. Regulate the idle speed control (ISC) valve: At low temperatures, the ECU actuates the idle speed control valve based on the temperature signal to raise engine idle RPM.

4. Influence EGR (Exhaust Gas Recirculation) valve operation;