A/C-Heater Programmer
WARNING: This page is about a different car, the 1998 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
The programmer receives signals from the A/C-heater control panel, solar load sensors, ambient temperature sensor, in-vehicle temperature sensor, blower control module, Powertrain Control Module (PCM), mode selector switch and actuators. A microprocessor in the programmer processes the signals and then sends commands to the system components to control A/C compressor clutch operation, air intake location, air discharge location, air discharge temperature and blower speed.
The programmer also performs self-diagnostic functions for the electric A/C-heater system. Diagnostic Trouble Code (DTC) can be retrieved using a scan tool.