A/C Operation Description at ECM
WARNING: This page is about a different car, the 2010 Suzuki Kizashi. However, it is still accessible from the selected car via links, so may be relevant.
When ECM receives A/C switch ON signal sent from HVAC control module via CAN communication system, it controls A/C compressor relay and radiator (condenser) cooling fan relay. The A/C switch ON signal from HVAC control module is transmitted to ECM through BCM. For CAN communication system, refer to COMMUNICATION SYSTEM DESCRIPTION .