Air Distribution and Filtering

AIR DISTRIBUTION AND FILTERING

Air Distribution
There are 2 sources of air available to the air distribution system:
- Outside air
- Recirculated air

Recirculated air is always used when the climate control assembly is set to the MAX A/C mode on vehicles equipped with electronic manual temperature control (EMTC) and can be selected in any mode except DEFROST. Vehicles equipped with dual-zone electronic automatic temperature control (EATC) use recirculated air only when the RECIRC function is selected in any mode other than DEFROST, or when required by the HVAC module in the AUTOMATIC mode.

RECIRC is a timed function when selected while operating in FLOOR or FLOOR/DEFROST mode, and will automatically default back to fresh air inlet in 5 minutes if operating with A/C ON at an ambient temperature below 10°C (50°F). When operating with A/C OFF, the RECIRC function will always default back to fresh air inlet in 5 minutes regardless of ambient temperature.

Air distribution within the vehicle is determined by the airflow mode selected, or by the dual-zone EATC system in the AUTOMATIC mode. The air distribution mode on vehicles equipped with dual-zone EATC can be overridden by the driver if desired. Airflow mode control doors are used to direct airflow within the heater core and evaporator core housing. Electric mode door actuators are used to position these airflow mode doors.

Vehicles equipped with dual-zone EATC use 2 separate temperature blend doors. This allows individual temperature settings to be selected for the RH and LH air outlets. The airflow mode doors are not partitioned for separate RH and LH airflow positions. Therefore, the airflow mode will always remain similar for the RH and LH sides of the vehicle regardless of the temperatures selected.

Air enters the passenger compartment from the following outlets:
- Instrument panel registers
- Floor duct outlets
- Windshield defroster
- Side window demisters
- Rear footwell duct
- Center console registers

Passenger compartment air is exhausted from the vehicle through open windows or body air vents.

Cabin Air Filter
A cabin air filter is available as standard equipment on dual-zone EATC vehicles. EMTC vehicles are not equipped from the factory with a cabin air filter, but are equipped with a screen in place of the filter to prevent any large foreign material from entering the heater core and evaporator core housing. The cabin air filter or screen can be accessed by removing the glove compartment and removing the cabin air filter access cover.

A cabin air filter can be installed as a dealer accessory on vehicles not originally equipped with a filter, but only a screen or a filter should be installed, never both.