US Patent 7311314 Vehicular suspension system

A vehicular suspension system having a fluid circuit including two fluid cylinders provided on respective front-wheel and rear-wheel sides, and two fluid passage systems one of which connects one of two fluid chambers of the fluid cylinder on the front-wheel side to the corresponding one of the two fluid chambers of the fluid cylinder on the rear-wheel side, and the other of which connects the other fluid chamber of the front-wheel side fluid cylinder to the other fluid chamber of the rear-wheel side fluid cylinder, the suspension system including a diagnosing device operable to diagnose the fluid circuit for any abnormality, on the basis of at least one of fluid pressures in the two fluid passage systems.