A/C Request Signal

The A/C request circuit signals the PCM when an A/C mode is selected at the A/C control head. The PCM uses this information in order to enable the A/C compressor clutch and to adjust the idle speed before turning ON the A/C clutch. If the A/C high pressure switch is open, the A/C request will not be detected by the PCM. The PCM also disables the A/C compressor clutch if the A/C request signal is not available to the PCM due to a high refrigerant pressure condition.