Front Control Panel

FRONT CONTROL PANEL
The front A/C-heater control and integral computer is mounted in the instrument panel and contains:
- a power button which allows the system to be completely turned off. The display is blank when the system is off.
- a rocker switch that selects a cool-down rate. LO-AUTO or HI-AUTO are displayed when the system is in automatic operation.
- three rocker switches that select comfort temperatures from 15° to 30° C (59° to 85° F), which are shown in the VF digital display. If the set temp is 15° C (59° F) and the down button is pressed, the set temp value will become 13° C (55° F) but the display will show LO. If the set temp is 29° C (85° F) and the up button is pressed, the set temp value will become 32° C (90° F) but the display will show HIGH. Temperatures can be displayed in either metric or Fahrenheit, which is controlled from the overhead console.
- an air conditioning button that allows the compressor to be turned off. A Snowflake symbol is illuminated when air conditioning is on, whether under manual or automatic control.
- an air recirculation button. A Recirculation symbol appears in the display when the button is pressed, or when the system exceeds 80 percent circulated air under automatic control due to high air conditioning demand.
- a rear window defogger on/off switch. A graphic symbol shows when the defroster is on.
- a rotary knob for front fan speed selection can override the automatic controls. LEDs surrounding the knob show the current setting.
- a rotary knob for control of the rear system.
- a rotary knob for mode control can override the automatic controls. LEDs surrounding the knob show the current setting.
- computer logic which remembers the settings of the controls when the ignition is turned off and retains those settings after a restart. If the system is off when the ignition is turned off it will be off when the engine is restarted, etc.
- computer logic which provides variable air recirculation under high temperature and humidity conditions. Because recirculation is generally accompanied by increased fan noise, the proportion of recirculated to outside air gradually approaches full recirculation over a broad temperature range.
- computer logic which enables additional heat for diesel equipped vehicles by using a supplemental engine coolant heater.

- AUTO HI/LO - This system features two sets of automatic control logic that allow either a rapid cool-down rate or a somewhat slower cool-down rate with less fan noise. HI-AUTO controls the system to reach its assigned temperature quickly with a higher fan speed. LO-AUTO controls the system to reach its assigned temperature somewhat slower with less fan noise. Both modes will automatically engage auto recirculation.
- DE-FROST - The defrost function is active when the rear window defogger function is active or when the defog/defrost mode is selected.
- RECIRC - The RECIRC button will close the air inlet door. If the system is in auto recirc (indicator being displayed automatically), pressing the manual recirc button will disable the auto recirc function until one of the auto keys are pressed or the ignition is cycled. If Auto HI/LO is pressed while manual recirc is active, manual recirc will be deactivated.
- REAR WINDOW DEFOGGER - Pushing the button sends a PCI bus message to the Intelligent Power Module which controls the Rear Window Defogger and side view mirror (if equipped) circuitry. The defogger function will be active for 10 minutes and can be turned off by a switch press. The defogger will function while the control is in the ON mode.
- FAN/MODE - The Fan and Mode knobs have 17 manual selectable positions. Manually changing either of the rotary knobs for mode or fan speed settings makes control of that blower motor manual. If only one is changed manually, the other remains under automatic control. Pressing the HI-AUTO/LO-AUTO rocker switch restores full automatic control.
- REAR CONTROL - When the Rear System control knob is moved to the OFF position, there will be a delay of approximately 1 second before the system actually turns off. This delay is to prevent an undesired blower dropout if the knob is moved through OFF to the other selections.
- BLOWER DELAY TIMER - The word DELAY is displayed at start-up to signify that the system is waiting so that cold air will not be blowing. This tells the operator that it is unnecessary to turn the system off, raise the temperature setting or turn the fan speed setting down to prevent cold air from blowing. A countdown in minutes and seconds until the engine is warm enough to begin delivering heat to the passengers alternates with the DELAY message at 25 second intervals. This countdown is based on actual measurement of the rate of engine coolant temperature change. During the delay time, mix mode is selected and the fan operates at a low speed to keep the windshield fog free.