A/C Control Module (ACCM)

When A/C function is selected, ACCM sends a request signal to PCM about .5 second before A/C clutch is energized. PCM increases engine idle speed to compensate for increased engine load. About .5 second before ACCM de-energizes A/C compressor clutch, ACCM stops sending request signal and PCM reduces idle speed to compensate for decrease in engine load.