A/C Compressor Clutch Controls

To provide improved idle quality, improved Wide Open Throttle (WOT) performance and A/C system protection, the A/C compressor clutch is controlled by the PCM.

Refrigerant switches used are a low pressure cut-off switch (some models), and an A/C pressure sensor. The A/C compressor clutch relay is controlled by PCM according to information received from refrigerant switches and various other sensors. This allows the PCM to raise idle speed before engaging compressor clutch, and disable compressor clutch during WOT, incorrect refrigerant pressure, or if coolant temperature becomes excessive. PCM inhibits A/C compressor clutch operation with engine speed greater than 4500 RPM for 5 seconds, or when throttle angle exceeds 90 percent.