There is provided a failure determination system for a continuously
variable transmission of a belt type, which is capable of determining
failure of control valves for performing speed varying operation, and
enhancing maintainability. An ECU controls a transmission ratio of the
transmission to a fixation-determining LOW-side range when the vehicle is
standing. When the transmission ratio during stoppage of the vehicle is
within a stop-time OD-side range if engine torque.gtoreq.OD-time DR-side
reference torque and at the same time the transmission ratio