Control Components - Electronic Automatic Temperature Control (EATC): Notes

With the use of a microcontroller, the electronic automatic temperature control (EATC) module (18C612) analyzes input from the following major sources:

• temperature, air distribution and blower selection (made by the vehicle occupants)
• in-vehicle temperature
• ambient temperature
• sunload
• vehicle speed
• engine coolant temperature

Using these inputs, the microcontroller determines the correct conditions for the following outputs:

• A/C compressor clutch (19D786) operation
• blower speed
• air temperature blend door position
• plenum/floor door position
• windshield defroster door position
• air inlet door position
• floor console door position.