A/C Request, Input

A/C Circuit.:

PURPOSE
This signal tells the PCM that the A/C selector switch in turned "ON". The PCM uses this information to adjust idle speed when the A/C is working. If this signal is not available to the PCM, the A/C compressor will not engage.

OPERATION
When the HVAC control assembly is placed in the A/C mode, a signal is sent to the A/C pressure cycling switch. If a predetermined amount of pressure is present in the system, the pressure switch will allow the signal to pass to the PCM.