Operating system for an automatic transmission for a vehicle

An operation apparatus for a vehicle automatic transmission mechanism includes first and second actuators (22A, 22B), connected in parallel with a hydraulic valve (16), for driving the hydraulic valve (16) to switch a travel range of an automatic transmission mechanism (12), a control unit (30) for controlling the first and second actuators (22A, 22B), and a transmission operation unit (10) for outputting a range signal indicating a presently set travel range to the control unit (30). The transmission operation unit (10) includes a stroke contact type operation switch (18) on which travel ranges to be set are sequentially aligned along a predetermined path. The control unit (30) includes a first CPU (30A), connected to the first actuator (22A), for controlling a driving operation of the first actuator, a second CPU (30B), connected to the second actuator (22B), for controlling a driving operation of the second actuator, and a third CPU (30C), connected to the first and second CPUs (30A, 30B), for setting, in a driving state, one of the first and second actuators (22A, 22B) connected to one of the first and second CPUs (30A, 30B), which CPU serves as a main unit, for monitoring system failed states of the first and second CPUs, for, when the third CPU determines that a system failed state occurs, inhibiting the driving operation of the actuator (22A, 22B) connected to the system-failed CPU, and for permitting the driving operation of the actuator (22A, 22B) connected to the CPU which does not suffer from the system failed state.