Control Module HVAC: Description and Operation

EATC Module
The EATC Module:
^ is located in the instrument panel.
^ has a vacuum fluorescent display for displaying set temperature, function and Diagnostic Trouble Codes (DTCs).
^ utilizes an On-Board Diagnostic (OBD) feature to supply the technician with diagnostic trouble codes (DTCs). These DTCs help direct the technician to the inoperative component.

Blower Motor Speed Control
The blower motor speed control:
^ is located on the evaporator core housing behind the suction accumulator.
^ varies the blower motor speed and is controlled by the EATC module.
^ uses low power signals from the EATC module to control a high-current, variable ground feed to the blower motor.
^ has a delay function to provide a gradual increase or decrease in blower motor speed under all conditions.
^ controls the integral high blower speed relay which is engaged when maximum fan speed is selected.