In-Car Temperature Sensor

The Automatic Temperature Control (ATC) in-car temperature sensor returns electrical signals to the Body Control Module (BCM). The in-car temperature sensor is used on ATC equipped vehicles only. The in-car temperature sensor is made up of two parts. One part is the in-car sensor aspirator motor assembly, and the second part is a temperature thermistor. The in-car sensor aspirator motor assembly attaches to the back of the ATC control head. See Fig 1 . This assembly has a small fan and a motor which draws air through the intake on the front of the ATC control. The in-car sensor thermistor is located inside of the. ATC control head. The in-car sensor aspirator motor is part of the ATC Control and not a separate serviceable part. The ATC control must be replaced if there is a fault relating to the motor. The in-car temperature sensor thermistor is part of the ATC control and not a separate serviceable part. One must replace the ATC control if the ATC self-diagnostics indicates a fault code. See SELF-DIAGNOSTIC SYSTEM  .

Air drawn from the passenger compartment by the in-car sensor aspirator motor assembly, and flows over the thermistor. The in-car sensor thermistor changes resistance with air temperature. The BCM measures this resistance and calculates the temperature of the air drawn into the ATC control. The ATC system then makes adjustments to maintain the optimum passenger compartment comfort. See IN-CAR SENSOR ASPIRATOR MOTOR OPERATION  table.

Fig 1: Identifying Automatic HVAC Control Head

Courtesy of CHRYSLER CORP.