Automatic Temperature Control (ATC) System

AUTOMATIC TEMPERATURE CONTROL (ATC) SYSTEM





The A/C-heater control for the automatic temperature control (ATC) single zone system maintains the interior comfort level desired by the vehicle operator. This is accomplished by use of an infrared sensor located in the overhead console that measures the surface temperature of the driver and front seat passenger. Based on the sensor input, the system automatically adjusts the air temperature, airflow volume, airflow distribution and amount of inside air recirculation to maintain front seat occupant comfort, even under changing outside weather conditions. All controls are identified by ISO graphic symbols.

This ATC system offers several manual override features such as fan speed, airflow distribution and when the outside air contains smoke, odors, high humidity, or if rapid cooling is desired, the interior air can be recirculated by pressing the recirculation button.

The heating-A/C system uses electrically operated controls. These controls provide the vehicle operator with a number of setting options to help control the climate and comfort within the vehicle.

The A/C-heater control is located in the instrument panel and contains:

- a rotary control for manual and automatic blower motor speed selection and to turn the blower motor off (1).
- a rotary control for temperature control of the discharged air (2).
- a rotary control for manual and automatic mode control of the discharged air (3).
- a push-button control with indicator lamp for manual recirculation control of the discharged air (4).
- a push-button control with indicator lamp to manually turn the A/C system on and off (5).
- a push-button control with indicator lamp to turn the rear window defogger system on and off (6).

The A/C-heater control for the ATC heating and A/C system obtains vehicle speed, engine speed, engine coolant temperature, ambient temperature and refrigerant system head pressure data from the CAN-B bus and is diagnosed using a scan tool.

Prior to replacing an A/C-heater control, check for any diagnostic trouble codes (DTCs) related to the heating-A/C system and run the Actuator Calibration function using a scan tool to verify that the concern is not a system issue HVAC System Test.

The A/C-heater control cannot be adjusted or repaired and must be replaced if found inoperative or damaged.