Patent ID: 7113082

Claim:
A speedometer control system, including: a drive-shaft rotation detection unit for outputting a detection signal corresponding to rotation of a drive shaft connected to driving wheels; a first control portion for outputting a signal corresponding to a vehicle speed based on the detection signal of the drive-shaft rotation detection unit; wheel rotation detection units for outputting detection signals corresponding to the rotations of respective wheels mounted on a vehicle; a second control portion for outputting a signal corresponding to a vehicle speed based on the detection signals of the wheel rotation detection units; a speedometer for displaying vehicle speeds; and a speedometer control portion for receiving the signals corresponding to the vehicle speed from the first control portion and the second control portion, and outputting the signals to the speedometer, characterized in that, while the first control portion is outputting the signals corresponding to the vehicle speed in a normal state, the speedometer control portion outputs to the speedometer the signal corresponding to the vehicle speed output from the first control portion, the speedometer displaying the vehicle speed based on the signal corresponding to the vehicle speed output from the first control portion, and that when the first control portion does not output the signal corresponding to the vehicle speed in the normal state, the speedometer control portion outputs to the speedometer the signal corresponding to the vehicle speed output from the second control portion, the speedometer displaying the vehicle speed based on the signal corresponding to the vehicle speed output from the second control portion.