8-98023581-0 Engine Parts Fuel Temperature Sensor for ISUZU 4HK1 6HK1 The role of the water temperature sensor:Measure the coolant temperature for cold start, fan control, target idle calculation, etc. It is used to detect the temperature of the coolant and use it as a correction signal for fuel injection. Provide water temperature signal to the water temperature gauge to facilitate real-time understanding of the water temperature status.