Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Air Distribution: Notes
There are two sources of air available to the air distribution system:
- outside air
- recirculated air
Recirculated air is used when the manual climate control mode selector is set in the MAX A/C, OFF or if the RECIRC button is selected in any mode except DEFROST. If the vehicle is equipped with a EATC system, recirculated air is used in OFF and is available in all modes except DEFROST.
Air distribution within the vehicle is determined by the EMTC mode selections, or is controlled by the EATC system in the AUTOMATIC mode. The air distribution mode on EATC vehicles may be overridden by the driver if desired. Three actuated airflow mode doors are used to direct airflow within the heater core and evaporator core housing and the plenum chamber (18471).
Vehicles equipped with dual-zone EMTC and EATC systems use a partitioned plenum chamber, and heater core and evaporator core housing assembly with two separate temperature blend doors. This allows for individual temperature settings to be selected for the RH and LH air outlets. The airflow mode doors are similar for EMTC and EATC systems, therefore the airflow mode for the RH and LH outlets will remain similar in all modes, regardless of the selected temperature settings.
Air enters the passenger compartment from the:
- instrument panel A/C registers (19893).
- heater outlet floor ducts (18C433).
- windshield defroster duct (18490).
- side window demisters.
Passenger compartment air is exhausted from the vehicle through open windows or body air vents.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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