Components & Functions: Programmer

The programmer is located behind the glove box attached to the HVAC module. It can be identified by the electrical and vacuum connectors attached to it. Contained within the programmer are circuits which control many of the various climate control systems.

These circuits respond to the BCM data signals, and provide controls for temperature regulation. This is done by a small DC motor that adjusts the air mix door position to blend cold and warm air. The motor provides position feedback signal to the BCM which monitors actual door position.

These circuits also respond to the BCM data signals to operate four vacuum solenoids mounted within the programmer. These solenoids control vacuum to 3 vacuum actuators, which control the air inlet door, A/C-defrost door and a 2 position actuator for the up-down door.

The programmer circuits also receive a blower motor signal from the BCM which transfers it to the blower control power module for blower speed operation. These circuits also receive a blower feedback signal used to regulate actual blower speed and voltage.

The programmer also provides a control for the rear defogger. When the programmer receives a rear defogger signal, it provides a ground to activate the rear defogger relay.