A vehicle control system for an automatic transmission of a vehicle, the vehicle control system comprising: a first operation part operable for issuing an instruction for shifting a range of the automatic transmission and outputting a first instruction signal representing an instruction for shifting the range; a second operation part (16, 704) provided separately from the first operation part, the second operation part being operable for issuing an instruction concerning an additional function added to essential functions that are essential for driving the vehicle and outputting a second instruction signal representing an instruction related to the additional function; and a by-wire control part (26-28, 30, 700) for controlling a change-over of the shift range normally according to the first instruction signal input from the first operation part as a reference signal, wherein the by-wire control part (26-28, 30, 700) includes signal monitoring means for monitoring the first instruction signal input from the first operation part, and substitute processing means which uses the second instruction signal input from the second operation unit as the reference signal to control the change-over of the shift range if the first instruction signal is determined to be abnormal by the signal monitoring means, characterized in that the by-wire control part (26-28, 30, 700) has speed monitoring means for monitoring a speed of the vehicle; and the substitute processing means uses the second instruction signal as the reference signal, if the signal monitoring means has determined that the first instruction signal is abnormal and the speed monitoring means has determined that the speed is lower than the preset threshold value. a first operation part operable for issuing an instruction for shifting a range of the automatic transmission and outputting a first instruction signal representing an instruction for shifting the range; a second operation part (16, 704) provided separately from the first operation part, the second operation part being operable for issuing an instruction concerning an additional function added to essential functions that are essential for driving the vehicle and outputting a second instruction signal representing an instruction related to the additional function; and a by-wire control part (26-28, 30, 700) for controlling a change-over of the shift range normally according to the first instruction signal input from the first operation part as a reference signal, wherein the by-wire control part (26-28, 30, 700) includes signal monitoring means for monitoring the first instruction signal input from the first operation part, and substitute processing means which uses the second instruction signal input from the second operation unit as the reference signal to control the change-over of the shift range if the first instruction signal is determined to be abnormal by the signal monitoring means, characterized in that the by-wire control part (26-28, 30, 700) has speed monitoring means for monitoring a speed of the vehicle; and the substitute processing means uses the second instruction signal as the reference signal, if the signal monitoring means has determined that the first instruction signal is abnormal and the speed monitoring means has determined that the speed is lower than the preset threshold value.