Intake Air Control - Dual Zone Automatic System

The intake air source is controlled automatically unless overridden by pressing the fresh/recirculated air switch located on the control panel. Under automatic control, the ATC module determines the required position of the air intake door using its 'comfort' algorithm based on inputs from the ambient air temperature sensor and the cabin temperature sensor.

When the vehicle first enters power mode 6 (ignition on), the tell-tale LED on the fresh/recirculated air switch will be illuminated and the air intake source will be automatically controlled by the ATC module. The ATC module will control the intake air source according to ambient air temperature and requested cabin temperature. The intake air door will be opened to allow fresh air into the cabin, although a small amount of recirculated air will also be present.

NOTE: The ATC module will reduce the amount of fresh air entering the cabin to reduce the ram effect caused by forward motion of the vehicle.

A single press of the fresh/recirculated air switch will extinguish the tell-tale LED. The ATC module will now close the air intake door and provide only recirculated air into the cabin for a period of 3 minutes. After this period, the ATC module will return the air intake door to automatic control. This helps prevent misting within the cabin.

A second press of the fresh/recirculated air switch will also return the intake air source to automatic control and illuminate the tell-tale LED.

The 3 minute time period for recirculated air can be overridden by pressing and holding the fresh/recirculated air switch until the switch LED flashes 3 times. The air intake door will now remain closed until the next drive cycle.

The ATC module controls the position of the air intake door by providing LIN bus messages to the air intake door stepper motor. A Hall effect sensor located within the stepper motor informs the ATC module that movement of the stepper motor is taking place.