Programmer Assembly

The programmer is attached to the Heating Ventilation and Air Conditioning (HVAC) module assembly behind the glove box. Within the case are the functional components described below.

The electronic circuit board accepts data signals from the Body Control Module (BCM) and, in response to these signals, provides the controls for temperature regulation.

The circuit board controls a small dc motor that adjusts the air mix valve position to blend cold and warm air. The motor is reversible and moves a rotary shaft which drives the air mix valve link. The motor also provides a position sensor signal back to the BCM to monitor actual valve position.

The circuit board also responds to the BCM data signals to operate the three vacuum solenoids mounted within the programmer. The solenoids control vacuum to the various vacuum actuators which in turn control the air inlet (recirc.) valve, AC - DEFROST valve and the UP-DOWN valve.


NOTE: When diagnosing vacuum actuator/system problems, the programmer must be kept in the as installed position in order for it to operate properly. Rotating or tipping the programmer may prevent the internal solenoid valves from shifting.