Module, HVAC: Description
AUTOMATIC TEMPERATURE CONTROL (ATC) ONLY
The Heating, Ventilation and Air Conditioning (HVAC) module is located in the instrument panel center stack and contains:
| 1. | Heated glass button |
| 2. | Compressor ON/OFF button |
| 3. | Blower speed adjustment knob |
| 4. | Upper air distribution button |
| 5. | Defrost ON/OFF button |
| 6. | AUTO button |
| 7. | Passenger side temperature adjustment knob |
| 8. | Passenger side temperature display |
| 9. | SYNC button |
| 10. | Vent air distribution button |
| 11. | Lower air distribution button |
| 12. | Control unit ON/OFF button |
| 13. | Recirculation button |
| 14. | Driver side temperature display |
| 15. | Driver temperature adjustment knob |
The Automatic Temperature Control (ATC) single zone heating and A/C system maintains the interior comfort level desired by the vehicle operator. This is accomplished by use of two air duct temperature sensors, located in the HVAC housing, that measure the temperature of the conditioned air leaving the HVAC housing and an in-car temperature sensor, located behind the rear view mirror, that measures the temperature of the conditioned air within the vehicle. Based on the sensors inputs, the ATC system automatically adjusts the air temperature, airflow volume, airflow distribution and amount of inside air recirculation to maintain occupant comfort, even under changing outside weather conditions. All controls are identified by International Standards Organization (ISO) graphic symbols.
The ATC heating and 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 and offers several manual override features such as fan speed and airflow distribution. When the outside air contains smoke, odors, high humidity, or if rapid cooling is desired, the interior conditioned air can be recirculated within the vehicle.
The A/C heater control for the ATC heating and A/C system obtains vehicle speed, engine speed, engine coolant temperature and refrigerant system head pressure data over the Controller Area Network (CAN) data bus and is diagnosed using a scan tool. Refer to DIAGNOSIS AND TESTING .
Prior to replacing the A/C heater control, check for any Diagnostic Trouble Codes (DTCs) related to the heating and A/C system, and run the Actuator Calibration function using a scan tool to verify that the concern is not an air door calibration issue. Refer to STANDARD PROCEDURE .
The A/C heater control cannot be adjusted or repaired and must be replaced if inoperative or damaged.