Identification and Detection of Thermistor-Based Water Temperature Sensors 3

② Check the output signal voltage of the water temperature sensor. When the engine is running, measure the voltage signal value output by the water temperature sensor from the "B" terminal of the water temperature sensor connector or from the "2" terminal of the ECU connector, as shown in Figure 3 (b) above, using the voltage range of the multimeter. The voltage level should change with the temperature of the cooling water. When the temperature is low, the signal voltage is high, and when the temperature is high, the signal voltage is low. The measurement results should comply with the provisions of Table 3.  diode,

Table 2-3 Voltage Values of Beijing Cherokee Automotive Cooling Water Temperature Sensor at Various Temperatures

③ Check the resistance value of the wiring harness connecting the water temperature sensor and ECU. Measure the resistance between the sensor signal terminal "B" and the "2" terminal of the ECU, as well as the resistance between the sensor ground terminal "A" and the "4" terminal of the ECU, using a high impedance multimeter Ω. The circuit should be conductive. If it is non-conductive or the resistance value is greater than 1 Ω, it indicates that the sensor harness is open or the connector is poorly connected, and further inspection or replacement should be carried out.diode,