PURPOSE: To bidirectionally effectively transfer information and a signal between a steering wheel side and a vehicle body side by communicating interface modules respectively disposed at the wheel side and the body side with one another through a bus, and introducing a touch switch to an input end of the wheel side.

CONSTITUTION: Interface modules 3, 4 of a steering wheel side and a vehicle body side communicate with one another through a bus 6. Touch switches 8, 9, 10, 11, 15, 16, 20, and 22 and issuing diodes 12, 17, 18, 21, 23, and 28 are introduced to corresponding input ends of the module of the wheel side. Output ends of the module of the body side are introduced directly to corresponding communicating opponents. As a result, relatively many functions relative to comfortableness of the vehicle can be operated at the wheel positions.