Auxiliary Heating and A/C Operation

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There are 2 separate controls for the auxiliary HVAC system. There is the front auxiliary HVAC control assembly and the rear seat audio control module. These 2 components provide passenger inputs to the auxiliary HVAC control module. The auxiliary HVAC control module, which is mounted on the auxiliary HVAC case, controls all functions of the auxiliary HVAC system. If the front auxiliary HVAC control assembly is in any other position than OFF or AUX, then the auxiliary HVAC control module will use inputs from the front auxiliary HVAC control assembly. If the system is in the AUX position then the auxiliary HVAC control module will use inputs from the rear seat audio control module. If the front auxiliary blower motor switch is in the OFF position, then the auxiliary HVAC control module does not respond to input. The auxiliary HVAC control module can not request A/C operation from the PCM.

Placing the auxiliary air temperature switch to the warmest position diverts most of the airflow through the heater core, which increases the outlet air temperature. Placing the auxiliary air temperature switch to the coolest position diverts most of the airflow around the heater core, which decreases the outlet air temperature.