A/C Request

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

When an A/C request is received by the PCM, the PCM engages the A/C clutch relay when all of the following conditions are met:

• the refrigerant pressure isn't excessively high or low.
• the engine coolant temperature isn't excessively high.
• the ambient air temperature is not below approximately 2 °C (35.6 °F).
• a WOT condition is not present.
• the evaporator discharge air temperature is not below approximately 2 °C (35.6 °F).