Engine Control Components
Engine Control ComponentsAir Conditioning Evaporator Temperature (ACET) Sensor
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 changes 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 and improve defrost/demist performance.
Note: These values can vary 15% due to sensor and VREF variations. Voltage values were calculated for VREF equals 5.0 volts.
A/C Evaporator Temperature (ACET) Sensor Voltage And Resistance Chart:
