Electronic Automatic Temperature Control: Notes

Two different electronic automatic temperature control (EATC) systems are available:

• Single-zone EATC (Fusion/Milan)
• Dual-zone EATC (MKZ)

The EATC module analyzes input from the following major sources:

• Temperature, airflow direction, blower, A/C and RECIRC selection (made by the vehicle occupants)
• In-vehicle temperature sensor
• Ambient temperature sensor
• Solar radiation sensor
• Vehicle speed
• Engine coolant temperature

Using these inputs, the dual-zone EATC module determines the correct conditions for the following outputs:

• A/C compressor operation
• Blower speed
• Temperature blend door position
• DEFROST/PANEL/FLOOR door position
• Air inlet door position