HEXA

HVAC 81 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.