Dual Automatic Temperature Control System

WARNING: This page is about a different car, the 2004 Mercury Mountaineer and 2004 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.

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

When the DATC 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 DATC 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. When RECIRCULATION mode is selected, A/C compressor operation is automatically requested (A/C request switch illuminates). 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 DATC 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 DATC 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. For additional information, refer to BODY SYSTEM - EXTERIOR .

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

the DATC system enables varying temperatures to be selected by the driver and the front passenger. Dual temperature control is indicated by the presence of two temperature settings on the DATC 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.