A MITSUBISHI Montreal off-road vehicle with a mileage of more than 200 thousand km has no effect in using the cruise control system to manipulate the control button. First of all, the road test for the car is carried out. When the speed exceeds 40km/h, the main control switch is pressed by the main control switch, the main switch indicator light is light, and the SET button of the integrated control switch is pressed, and the work indicator of the cruise system is not bright. After many operations, there was no reaction.