PCM Controlled Air Conditioning Description

A/C operation is requested by the ACM using a serial data (Class 2) message to the PCM. The PCM will ground the A/C relay allowing current to flow through the A/C Compressor clutch coil. The PCM will disable or inhibit A/C compressor clutch operation during the following conditions:
^ High power steering load indicated
^ Engine not running
^ Engine at wide open throttle Outside temperature below approximately 4°C (40°F)
^ Certain PCM DTCs set

The PCM will also engage the A/C compressor clutch during cranking in colder weather to prevent A/C slugging.