Electronic Climate Control
The Electronic Automatic Temperature Control (EATC) automatically maintains the temperature selected for driving comfort and regulates the airflow between the instrument panel registers, floor ducts and side window demisters. The system also provides the option of manually overriding the blower speed and/or airflow direction, described below. Additionally, the system has automatic solar compensation for high sunload conditions. This results in cooler interior temperatures. The sunload sensor is located in the upper lefthand corner on top of the instrument panel.
The outside temperature can also be displayed at any time by momentarily depressing the OUTSIDE temperature will then be displayed for four seconds.
Auto Control Operation
Depressing the AUTO button turns the system on in the fully automatic mode. The AUTO indicator will light up. The system automatically maintains the temperature selected by controlling the airflow direction (mode), the airflow quantity (fan speed), and discharge temperature required for comfort.
When heating is required, the airflow is automatically directed through the floor ducts and demisters with a small amount of air through the defroster. During cool weather, fan operation is delayed by cold engine lockout until the engine has heated sufficiently to provide warm discharge temperatures.
When cooling is required, airflow is directed through the instrument panel registers. The registers can be adjusted for optimum comfort. When maximum cooling is required, the system automatically operates is recirculating mode for rapid cool down and automatically changes to outside air as the vehicle interior approaches the selected temperature.
In some moderate ambient conditions, the system can automatically operate in a split mode with airflow directed through the floor ducts and windshield defroster nozzle at a moderate temperature and fan speed. This split mode is typically a transient condition.
Cooler
The blue button is used to lower the temperature setting. Pressing the button once lowers the temperature one degree. Holding the button in continuously reduces the temperature setting in one degree increments to 18~C (65~F) and then 15~C (60~F) in one step for continuous maximum cooling.
Warmer
The red button is used to raise the temperature setting. Pressing the button once raises the temperature one degree. Holding the button in continuously raises the temperature setting in on degree increments to 20~C (85~F) and then to 32~C (90~F) in one step for continuous maximum heating.
Defrost
Depressing the DEFROST button lights the DEFROST indicator and directs the majority of the airflow through the defroster nozzle with a small bleed to the side window demisters and the floor ducts.
Floor
Depress the FLOOR button displays "FLOOR" in the display window. The majority of the air is directs through the floor ducts with a small bleed to the side window demisters and the defroster nozzle.
Floor Defrost
Depressing the FLR DEF button displays "FLOOR DEFROST" in the display window and results in a MIX position with the air distributed equally between the defroster nozzles and the floor ducts with a small bleed out the side window demisters.
Vent
Depressing the vent button displays "VENT" in the display window. The system operates with fresh air directed through the instrument panel registers, and the A/C Clutch turns off.
Panel and Floor
Depressing the PNL-FLR button displays "PANEL FLOOR" in the display window. The air is discharged equally between the instrument panel registers and the floor ducts, and the A/C Clutch is turned on.
Max A/C
Depressing the MAX A/C button displays "60 MAX A/C" in the display window. The system goes to high blower with a maximum cool discharge temperature while also going into recirculation mode.
Off
Depressing the OFF button turns off the system completely and displays "OFF" in the digital display window.
Auto Indicator
The Auto Indicator lights up when the AUTO button is depressed. The system then automatically directs the airflow and controls the fan speed as previously described. Depressing any of the five override buttons locks the system in a fixed mode and turns off the Auto Indicator. The appropriate override indicator then lights up.
Digital Display Window
The Digital Display Window indicates one of three displays, depending upon customer service: selected comfort temperature, outside temperature and OFF (when system is off).
The function is also displayed if manually selected. If in AUTO position, only AUTO appears with the selected temperature or ~C can be displayed by depressing in MPH/KMH button on vehicles equipped with the digital instrument cluster option. Only ~F is displayed on vehicles equipped with mechanical clusters (Canadian vehicles will display ~C only).
Outside
Depressing the OUTSIDE button displays the outside temperature for four seconds and automatically changes back to the previous display. Outside temperature can be selected any time the Ignition Switch is in the RUN position, whether the system is on or off.
Blower Speed Override Knob
Rotating the blower speed override knob more than 10 degrees turns on the fan indicator and provides manual control of the blower speed. Rotating the knob fully up against the stop locks the blower at its highest speed. Depressing the AUTO button resumes automatic blower control and the fan indicator lights turns off.
A/C Clutch Operation
The A/C clutch circuit is connected in series with the EEC Module, the Integrated Control Module and the Heated Windshield Control Module (on vehicles equipped with the option). A/C operation may be interrupted by any of these modules.