Patent ID: 8380403

Claim:
A vehicle comprising: an internal combustion engine including an output shaft; a stepped transmission comprising an input shaft connected to the output shaft of the internal combustion engine and an output shaft connected to an axle side, wherein the stepped transmission speed-changes power input to the input shaft while changing a shift speed and outputs the speed-changed power to the stepped transmission output shaft; a control unit that controls the internal combustion engine and the stepped transmission in accordance with an output request from an operator; an input shaft rotation speed detecting unit that detects an input shaft rotation speed; an output shaft rotation speed detecting unit that detects an output shaft rotation speed; an output limiting unit which, when a rotation speed relationship between the detected input shaft rotation speed and the detected output shaft rotation speed exceeds a range of a predetermined rotation speed relationship for determining an abnormality in the stepped transmission, limits an output of the internal combustion engine relative to the output request to a range in which the rotation speed relationship exceeds the range of the predetermined rotation speed relationship and the rotation speed of the input shaft does not exceed a predetermined upper limit rotation speed; and an abnormality determining unit to determine that an abnormality has occurred in the stepped transmission when the rotation speed relationship exceeds the range of the predetermined rotation speed relationship for at least a first predetermined time period, while limiting the torque of the engine and releasing the limitation repeatedly.