Patent ID: 7311314

Claim:
A suspension system for a vehicle, characterized by comprising: a fluid circuit including (a) at least one fluid cylinder provided on each of a front-wheel side and a rear-wheel side of the vehicle, each of said at least one fluid cylinder including a housing, and a piston which separates an interior space of the housing into two fluid chambers, said each fluid cylinder being disposed between a wheel-side member of the vehicle and a body-side member of the vehicle, such that there arises a difference between fluid pressures in said two fluid chambers when at least one of a left wheel and a right wheel is displaced in a vertical direction relative to a body of the vehicle, and (b) two fluid passage systems one of which connects one of the two fluid chambers of said at least one fluid cylinder on said front-wheel side to a corresponding one of the two fluid chambers of said at least one fluid cylinder on said rear-wheel side, and the other of which connects the other of the two fluid chambers of said at least one fluid cylinder on said front-wheel side to the other of the two fluid chambers of said at least fluid cylinder on said rear-wheel side; and a diagnosing device including a fluid-pressure detecting device operable to detect fluid pressures in said two fluid passage systems, said diagnosing device being operable to determine that said fluid circuit has an abnormality of fluid leakage, when a raised one of the fluid pressures in said two fluid passage systems detected by said fluid-pressure detecting device during turning of the vehicle causing an inclination of the body of the vehicle that causes said body to have a lower height on an outer side of a path of turning of the vehicle is lower than a lower limit determined by a force acting on said body so as to cause said inclination.