HEXA

HVAC

B. CONTROLS



PUSH BUTTONS

1. AI(

Air Inlet

) Control request (

Amber LED

The AI pushbutton shall be of non-latching type and

located on top of the hollow knob used to select the

blower speed. The AI door flap shall be controlled

either manually by the user pressing the AI control

button on the panel or automatically by the climate

control algorithm.

MANUAL OPERATION

As a manually selected two state function, the air

inlet door flap will be either outside air (

OSA

) or in-

cabin recirculation (

RECIRC

). The default position

shall be outside air (

OSA

). When the user pushes

the AI control request button, the air inlet door flap

shall move to the RECIRC position and the LED

shall turn on. The next time the user pushes the RE-

CIRC request button, the air inlet door flap shall

move to the OSA position and the RECIRC LED

shall turn off.

AUTO OPERATION

The AI

(AIR INTAKE)

control shall switch to Auto

operation immediately after the user presses the Au-

to request button. The status of the AI door flap shall

be calculated by the Climate control algorithm. Dur-

ing Auto operation, it shall be possible to stop the AI

door flap at intermediate positions between Recircu-

lation and OSA as required by the algorithm. The

LED shall not indicate the status of AI door flap dur-

ing Auto operation.

2. Normal A/C request (

Amber LED

)

The A/C request button shall be of non-latching type

and located on top of the hollow knob used to select

the cabin set temperature. Using this button, the user

shall be able to choose between Normal A/C and

A/C off state

3. Auto control request

By pressing the non-latching Auto request pushbut-

ton, the user shall be able to activate fully automatic

temperature control.

4. Rear defog request

The rear defog pushbutton shall be of non-latching

type and used to manually switch ON/OFF the rear

defog heater grids on the rear window. Enabling the

heater, allows the clearing/defogging of the rear win-

dow.

After ignition ON, the default value of the rear defog-

ger shall be OFF. The rear defogger shall be

activated by pressing the pushbutton on the control

panel during engine ON condition. The status of the

Rear defog shall be indicated on the display. If the

Rear defog switch is activated in any ignition cycle, it

shall remain on for a calibratible amount of time (

ap-

prox. 15 minutes

5. Front defrost request

The Front Defrost Request pushbutton shall be of

non-latching type and used to manually switch the air

distribution to defrost mode. This shall be used for

clearing/defogging the front windshield. The Air inlet

and the temperature door flaps shall be selected au-

tomatically to aid the window clearing operation.

6. Mode (

Air distribution

) selection button

The Mode selection pushbutton shall be of non-

latching type and used to manually select the air dis-

tribution modes. It shall be possible to manually

select the various distribution modes in a cyclic fash-

ion, for every push of the button.

The Mode control shall be functional at all times

when the control head receives the ignition voltage.

Mode control shall indicate the control of the air dis-

tribution inside the cabin. The Mode control shall

happen either manually or through an automatic cli-

mate control algorithm. The determination of the

desired mode position shall be described by the sim-

ple flow diagram below.

Mode control during Auto operation

The Mode control shall switch to Auto operation after

the user presses the Auto button. The desired mode

position shall be determined by the climate control

algorithm during Auto operation. The Auto operation

shall select among Chest, Chest-Leg and Leg posi-

tions during the Auto operation. Since the system

isn’t equipped with sensors to determine the wind-

shield fogging criteria, the Defog and Defrost shall be

selectable manually by the user. The display of the

mode-man icon shall remain blank and not indicate

the current mode during Auto operation.