Patent ID: 7886815

Claim:
An HVAC control system for a vehicle with front and rear HVAC systems, comprising: a coolant temperature sensor that senses engine coolant temperature; said front HVAC system include a front control panel that includes input devices that a user may manipulate in order to input control parameters, said front control panel including a rear manual switch that selectively enables rear manual control over the rear HVAC system: said rear HVAC system including a rear control panel that includes input devices to permit a rear user, when rear manual control is enabled via the rear manual switch on the front control panel, to control operation of the rear HVAC system; and, a controller that receives user inputs via the front and rear control panels as well as signals indicative of sensed conditions, including the measured engine coolant temperature, and controls operation of the front and rear HVAC systems; wherein, when the vehicle is shut off, the controller stores in memory a status of the rear manual switch and, wherein, when the vehicle is restarted, the controller accesses the status of the rear manual switch that is stored in memory and uses the rear manual switch status in conjunction with engine coolant temperature to determine whether to enable rear manual control via the rear control panel.