Power-based control method for a vehicle automatic climate control

A motor vehicle automatic climate control (42) computes the HVAC power requirement for cabin air temperature regulation, and determines corresponding air discharge temperature and blower motor speed commands using a two-step table look-up procedure. Nominal air discharge temperature and blower motor speed profiles are tabulated as a function of a Power Index generally corresponding to ambient temperature, and used along with the set temperature to form a table of HVAC power requirement vs. Power Index. In vehicle operation, the HVAC power requirement vs. Power Index table is used to retrieve a Power Index corresponding to the computed HVAC power requirement (116), and the air discharge temperature and blower motor speed tables are then used to retrieve air discharge temperature and blower motor speed commands based on the retrieved Power Index (118).