Electronic Automatic Temperature Control System

The electronic automatic temperature control (EATC) system operation is determined by the settings on the EATC module. The EATC system automatically maintains a selected temperature for vehicle interior comfort, including capabilities to maintain separate temperature settings for the driver and front passenger. The electronic temperature control capabilities are achieved by splitting the air distribution system internally and utilizing 2 individually operated temperature blend doors. The EATC system is composed of the EATC module, automatic temperature control (ATC) solenoid and manifold, blower motor speed control, 4 vacuum control motors, 2 temperature blend door actuators, in-car temperature sensor, ambient air temperature sensor and solar amplifier (sunload sensor) to control the various functions.

When the EATC module is set to AUTO:

• The air distribution direction, heater control valve operation and blower motor speed are automatically controlled based on the temperature(s) selected.

The EATC module manual override settings:

• Allow the air distribution direction to be manually selected.
• Allow the blower motor speed to be manually selected.
• Allow RECIRCULATION mode to be manually selected except in FLOOR/DEFROST and DEFROST. The A/C request can be cancelled by pressing the A/C request switch, turning the indicator off.
• Allow A/C compressor operation to be manually selected except in FLOOR/DEFROST and DEFROST.

The EATC module also includes:

• An EXT button to monitor ambient (outside) air temperature. By pressing the EXT button the ambient temperature will be displayed on the EATC module display until the EXT button is pressed again.
• A F°/C° temperature conversion button to toggle the temperature being displayed from Fahrenheit and Celsius.
• A rear window defrost button (Explorer only). For additional information, refer to GLASS, FRAMES AND MECHANISMS .

Dual temperature control can be enabled in AUTO or in all manual override settings. When the EATC module is set to DUAL:

• The EATC system enables varying temperatures to be selected by the driver and the front passenger. Dual temperature control is indicated by the presence of 2 temperature settings on the EATC module display. To return to single temperature control press the DUAL button, turning the DUAL button indicator off and the front passenger temperature display off.
• The air distribution direction and the blower motor speed cannot be varied between the driver and front passenger. Only the temperature settings can be varied.
• The system will favor the driver temperature setting if the driver and front passenger temperature set points vary greatly.