With Electronic Automatic Temperature Control (EATC)

Part 1:

Part 2:

With the use of a microcontroller, the Electronic Automatic Temperature Control (EATC) module analyzes input from the following major sources:
- temperature, function and blower selection (made by the vehicle occupants)
- in-vehicle temperature sensor
- ambient temperature sensor
- sunload sensor
- vehicle speed sensor
- engine coolant temperature sensor

Using these inputs, the microcontroller determines the correct conditions for the following outputs:
- A/C clutch engagement
- blower speed
- air temperature blend door position
- floor/panel door position
- panel/defrost door position
- air inlet duct door position

The Electronic Automatic Temperature Control (EATC) module, located in the instrument panel, has the following features:
- a blower speed override control for manual input
- a vacuum fluorescent display for displaying set temperature, ambient temperature, function and Diagnostic Trouble Codes (DTCs)
- an On-Board Diagnostic (OBD) feature to supply the technician with diagnostic trouble codes (DTCs). These DTCs direct the technician to the inoperative component.