A/C (Air Conditioning) Request

When the A/C is requested, the HVAC control module sends the message over the MS-CAN to the IPC. The IPC sends the A/C request to the PCM through the HS-CAN.

When an A/C request is received by the PCM, the PCM engages the A/C clutch relay when:

• the refrigerant pressure is not excessively high or low.
• the engine coolant temperature is not excessively high.
• the ambient air temperature is above approximately -2.2 °C (28.4 °F).
• a Wide Open Throttle (WOT) condition is not present.
• the evaporator discharge air temperature is above approximately 1.5 °C (35 °F).