Circuit Description

The A/C low side temperature sensor uses a thermistor to control the signal voltage to PCM. PCM applies 5 volts to A/C low temperature sensor circuit. When sensor is cold, sensor resistance is high and PCM will see a high signal voltage. As the sensor warms up, its resistance drops and signal voltage is pulled low through the ground circuit. This test detects a shorted to ground or open A/C low side temperature sensor circuit by setting DTC if the PCM monitors a signal voltage (temperature) that is too high or low.