Heater Core Temperature Sensor / Switch: Testing and Inspection

Heat Exchanger Temp. Sensor Location:

1. Remove the ACC control unit. Refer to COMPONENT REPLACEMENT AND REPAIR PROCEDURES.
2. Disconnect the heater sensor electrical connector.
3. Carefully pull the sensor out.
4. Place the sensor next to an accurate temperature gauge (thermometer) and allow enough time for the sensor and the gauge to adjust to the ambient temperature.
5. With a suitable ohmmeter, check the resistance of the sensor.

Temp. Sensor Resistance Values:

6. Compare the readings with the temperature chart.

If the resistance is not within the specified range, replace the evaporator (cooling) temperature sensor.