Expedition 4WD V8-5.4L VIN 5 (2006)
Evaporator Temperature Sensor / Switch: Description and Operation
AIR CONDITIONING EVAPORATOR TEMPERATURE (ACET) SENSOR
A/C Evaporator Temperature (ACET) Sensor Voltage And Resistance
The ACET sensor measures the evaporator air discharge temperature. The ACET sensor is a thermistor device in which resistance changes with
temperature. The electrical resistance of a thermistor decreases as the temperature increases, and the resistance increases as the temperature decreases.
The PCM sources a low current 5 volts on the ACET circuit. With SIG RTN also connected to the ACET sensor, the varying resistance affects the
voltage drop across the sensor terminals. As A/C evaporator air temperature changes, the varying resistance of the ACET sensor changes the voltage the
PCM detects.
The ACET sensor is used to more accurately control A/C clutch cycling, improve defrost/demist performance, and reduce A/C clutch cycling.
NOTE: These values can vary 15 percent due to sensor and VREF variations. Voltage values were calculated for VREF equals 5.0 volts.
