Cooling Fan Control
The automatic temperature control (ATC) module determines the amount of condenser cooling required from the refrigerant pressure sensor, since there is a direct relationship between the temperature and pressure of the refrigerant. The cooling requirement is broadcast to the engine control module (ECM) on the medium speed controller area network (CAN) bus. The engine control module (ECM) then controls the temperature of the condenser using the cooling fan. Refer to Electronic Engine Controls article.