Operation CHARM: Car repair manuals for everyone.

A/C Pressure Switches

The A/C system is protected by 2 pressure switches. The A/C high and A/C low pressure switches interrupt the A/C request signal when the A/C line pressure exceeds or falls below a predetermined value. When the PCM sees an open in the request signal, the A/C compressor clutch relay control circuit is no longer grounded, thus shutting off the compressor.