Component Functions: Programmer

The programmer is attached to the HVAC module behind the glove compartment. It can be identified by the electrical and vacuum connectors attached to it.

The programmer contains circuits which accept data signals from the BCM and provide controls for temperature regulation. The circuit board controls a small DC motor that adjusts air-mix door position to blend cold and warm air. This motor is reversible and moves a rotary shaft connected to the air-mix door. The motor also provides air-mix door position feedback to the BCM.

These programmer circuits also respond to BCM data signals which operate 4 vacuum solenoids mounted within the programmer. These solenoids control the actuators, which in-turn operate 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 it transfers to the power module for blower speed operation. These circuits also receive a blower motor feedback signal, which is used to regulate actual blower voltage.

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