Electronic Automatic Temperature Control

AUTO
When AUTO is selected:
- The temperature control setting is manually set to the desired settings.
- The air inlet door vacuum control motor is automatically controlled by the EATC module, based on the temperature setting.
- The mode door vacuum control motors are automatically controlled by the EATC module based on the temperature setting.
- The A/C compressor is automatically controlled by the EATC module based on the temperature setting. The A/C compressor will not operate if the outside temperature is lower than approximately 6°C (43°F).
- The blower motor is on. The blower motor speed is automatically controlled by the EATC module based on the temperature setting, but can be manually overridden.







OFF
When OFF is selected:
- The air inlet door vacuum control motor is at full vacuum, closing off outside air from entering the passenger compartment.
- The defrost door and floor console door (if equipped) vacuum control motors are at no vacuum, and the panel/floor door vacuum control motor is at full vacuum, closing off airflow to the defrost duct, side window demisters, floor duct, instrument panel A/C registers and center console registers (if equipped).
- The A/C compressor will not operate.
- The blower motor is OFF.







PANEL
When PANEL is selected:
- The air inlet door vacuum control motor is at no vacuum, admitting only outside air into the passenger compartment.
- The defrost door and floor console duct door (if equipped) vacuum control motors are at full vacuum and the panel/floor door vacuum control motor is at no vacuum, directing airflow to the instrument panel A/C registers and the center console registers (if equipped).
- The temperature can be adjusted to heat the air, but the air cannot be cooled below the outside temperature.
- The A/C compressor will not operate.
- The blower motor is on.







PANEL/FLOOR
When PANEL/FLOOR is selected:
- The air inlet door vacuum control motor is at no vacuum, admitting only outside air into the passenger compartment.
- The defrost door and floor console duct door (if equipped) vacuum control motors are at full vacuum and the panel/floor door vacuum control motor is at partial vacuum, directing airflow to the instrument panel A/C registers, the floor duct and the center console registers (if equipped).
- The temperature can be adjusted to heat or cool the air below the outside temperature.
- The A/C compressor will operate if the outside temperature is above approximately 6°C (43°F).
- The blower motor is on.







FLOOR
When FLOOR is selected:
- The air inlet door vacuum control motor is at no vacuum, admitting only outside air into the passenger compartment.
- The panel/floor door vacuum control motor is at full vacuum and the defrost door and floor console duct door (if equipped) vacuum control motors are at no vacuum, directing airflow to the floor duct.
- The temperature can be adjusted to heat or cool the air below the outside temperature.
- The A/C compressor will operate if the outside temperature is above approximately 6°C (43°F)
- The blower motor is on.







FLOOR/DEFROST
When FLOOR/DEFROST is selected:
- The air inlet door vacuum control motor is at no vacuum, admitting only outside air into the passenger compartment.
- The panel/floor door vacuum control motor is at partial vacuum and the defrost door and floor console duct door (if equipped) vacuum control motors are at no vacuum, directing airflow to the floor duct, the defroster duct and the side window demisters.
- The temperature can be adjusted to heat or cool the air below the outside temperature.
- The A/C compressor will operate if the outside temperature is above approximately 6°C (43°F).
- The blower motor is on.







DEFROST
When DEFROST is selected:
- The air inlet door vacuum control motor is at no vacuum, admitting only outside air into the passenger compartment.
- The panel/floor door, defrost door and floor console duct door (if equipped) vacuum control motors are at no vacuum, directing airflow to the defrost duct and the side window demisters.
- The temperature can be adjusted to heat or cool the air below the outside temperature.
- The A/C compressor will operate if the outside temperature is above approximately 6°C (43°F).
- The blower motor is on.

Electronic Automatic Temperature Control System Electrical Components, Part 1:

Electronic Automatic Temperature Control System Electrical Components, Part 2:

With Electronic Automatic Temperature Control A/C