US Patent 7312718 Multifunction control system

A control system for a vehicle with a plurality of selectively variable characteristics includes a first button depressible to cause a first mode of operation and a second button depressible to cause a second mode of operation. In the first mode of operation, a rotary dial is rotatable to cause variation of the first characteristic. In the second mode of operation, the rotary dial is rotatable to cause variation of the second characteristic. The control system thus enables a single dial to control multiple characteristics or multiple vehicle systems, which enables a corresponding reduction in the quantity of switches and other control input devices in a vehicle passenger compartment.