Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection

Fig. 4 Engine Coolant Temperature Sensor:

1. With key off, disconnect wire connector from engine coolant temperature sensor Fig. 4.
2. Connect one lead of ohmmeter to one terminal of engine coolant temperature sensor.
3. Connect the other lead of ohmmeter to remaining terminal of engine coolant temperature sensor. The ohmmeter should read as follows;
- Engine/Sensor at normal operating temperature around 200°F should read approximately 700 to 1,000 ohms.
- Engine/Sensor at room temperature around 70°F, ohmmeter should read approximately 7,000 to 13,000 ohms.
4. Test the resistance of the wire harness between the PCM connector terminal 26 and the sensor harness connector. Also check for continuity between connector terminal 43 and the sensor harness connector. Refer to Wiring Diagrams for circuit information. If the resistance is greater than 1 ohm, repair the wire harness as necessary.