Electronic Climate Control
System Block Diagram:
System Operation
The electronic climate control system automatically maintains the temperature selected for driving comfort, and regulates the airflow to the:
^ Instrument panel A/C registers
^ Heater outlet floor ducts
^ Windshield defroster hose nozzles
^ A/C side window demisters
The system also provides the option of manually overriding the heater blower motor speed and/or airflow direction as desired. Additionally, the system has automatic compensation for high sunload conditions. This results in cooler interior temperatures.
The A/C sunload sensor is located in the upper RH corner of the instrument panel near the defroster grille. For optimum automatic operation, the system should be in AUTOMATIC mode and set to the desired temperature setting. If the vehicle interior temperature is warmer or cooler than the set temperature, the climate control system will automatically provide heat (when the engine is warm) or air conditioning, as required, to reach the comfort setting as quickly as possible. It it is necessary to adjust the comfort setting, the selling should be changed only in small increments (1-2 degrees) to maintain comfort and avoid large variations of in-vehicle temperature. Raising or lowering the set temperature in large increments from the comfort setting will not reduce the time required to reach stabilized comfort.
AUTOMATIC
Press the AUTOMATIC button to turn the system on for fully automatic operation. When functioning automatically, the digital display window shows the selected temperature. The system maintains this temperature by controlling the airflow direction (function setting), the airflow quantity (fan speed) and the 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 directed through the windshield defroster hose nozzle. During cool weather, the fan operation is delayed until the engine has heated sufficiently to provide warm discharge temperatures.
When cooling is required, the airflow is directed through the instrument panel registers. The A/C registers can be adjusted for optimum comfort. When maximum cooling is required, the system automatically operates with recirculated air for rapid cool down, and automatically changes to outside air as the vehicle interior approaches the selected temperature.
In moderate conditions, the system automatically operates in a split manner, with airflow directed through the heater outlet floor ducts and through the windshield defroster hose nozzle at a moderate fan speed.
OFF
Press the OFF button to turn the system off completely.
Digital Display Window
The digital display window indicates selected function/comfort temperature.
Warmer (Red) Button
The red button raises the temperature setting. Press the button once to raise the temperature one degree. Press and hold the button to continuously raise the temperature setting in one-degree increments to 29° C (85° F), and then jump to 32 °C (90° F) in one step for continuous maximum heating.
Cooler (Blue) Button
The blue button lowers the temperature setting. Press the button once to lower the temperature one degree. Press and hold the button to continuously reduce the temperature setting in one-degree increments to 18°C (650 F), and then jump to 15 °C (60°F) in one step for continuous maximum cooling.
Rear Fan Off
Press this button to stop operation of the rear blower assembly. It will not permit rear blower operation until it is pressed a second time: "REAR FAN OFF" will show in the display.
Manual Overrides
There are six manual override buttons along the lower edge of the control assembly. The buttons affect system operation as follows:
MAX A/C
Press the MAX A/C button to show "60 MAX A/C" in the display window. The system goes to high blower motor operation with a maximum cool discharge temperature while also going into recirculation function (which uses air from inside the vehicle).
Vent
Press the VENT button to show "VENT" in the display window. The system operates with outside air in the panel function. The A/C clutch will be off.
PNL-FLR
Press the PNL-FLR button to show "PNL FLR" in the display window. The air is discharged equally between the panel and the floor.
FLOOR
Press the FLOOR button to show "FLR" in the display window. The majority of the air distribution is directed through the heater outlet floor ducts with a small bleed to the A / C side window demisters and the windshield defroster hose nozzle.
FLR-DEF
Press the FLR-DEF button to show "FLR and Defrost Symbol" in the display window air is distributed equally between the windshield defroster hose nozzle and the heater outlet floor ducts with a small bleed to the A/C side window demisters.
Defrost
Press the DEF button to show "Symbol" in the display window. The majority of the airflow is directed through the windshield defroster hose nozzle, with a small bleed to the A/C side window demisters and the heater outlet floor ducts.
Blower Speed Override Thumbwheel
Rotating the blower speed override thumbwheel more than 10 degrees will turn on the automatic blower indicator and provide manual control of the blower motor speed. Rotating the wheel fully down against its lower stop locks the blower at its lowest speed. Rotating the wheel fully up against the stop locks the blower at its highest speed.
Press the AUTOMATIC button to resume automatic blower control; "AUTOMATIC" shows in the display.