What is KDSS?
2 Answers
KDSS is the English abbreviation for Kinetic-Dynamic-Suspension-System, which translates to Dynamic Suspension System in Chinese. The KDSS structure mainly consists of an electronically controlled dynamic adjustment suspension system. Its function is to adjust the stabilizer bar and balance bar through hydraulic pressure, enhancing the vehicle's performance both on-road and off-road. It combines two opposing performance characteristics. KDSS mode selection for vehicles: There are two modes, Normal mode and Off-road mode. The front and rear stabilizer bars of KDSS each have independent hydraulic cylinders that control vertical movement, connected by a hydraulic system. Each stabilizer bar's hydraulic cylinder is divided into upper and lower chambers, with the front upper and lower hydraulics connected to the rear upper and lower hydraulics via respective hydraulic lines. Each hydraulic line contains an accumulator. KDSS controls a set of valves connected to the accumulator in the hydraulic lines to maintain each stabilizer bar in the optimal state. About KDSS: Composition of KDSS: Electronically controlled dynamic adjustment suspension system. It combines two opposing performance characteristics. Performance description of KDSS: In Normal mode, when the vehicle is in a turning state, it can effectively enhance anti-roll capability. KDSS mode selection: Normal mode: When the vehicle is in a turning state, the outer suspensions of the front and rear wheels are compressed, and the inner suspensions are extended. This causes the stabilizer bar to twist, resisting body roll. The two hydraulic lines between the connected hydraulic pumps have no fluid flow, functioning like a conventional suspension but with improved anti-roll capability. Off-road mode: When one of the four wheels encounters an obstacle and is lifted, the suspension of the lifted wheel is compressed, and the stabilizer bar rises with the hydraulic pump. Fluid flows between the two hydraulic lines of the front and rear pumps, absorbing the stabilizer bar's twist. Since the stabilizer bar does not twist, the suspension travel is greater than that of a conventional suspension and can be adjusted according to different road conditions. It can automatically deactivate the stabilizer bar's function based on road conditions. Working principle of KDSS: It uses two hydraulic cylinders to control a fixed point (left fixed point) on the front and rear suspension stabilizer bars. Under normal driving conditions, this fixed point is locked, and the stabilizer bar functions normally, performing anti-roll duties during turns. In off-road conditions, as the suspension is continuously compressed and extended, the fixed point is released, moving with the hydraulic cylinder. The rotational constraint of the stabilizer bar along the X-axis (vehicle length direction) is also released, allowing rotation around the right fixed point without any effect, ensuring no impact on wheel grounding. This allows significant vertical displacement between the left and right wheels, improving tire grounding performance and off-road capability.
I always love tinkering with these systems while driving. KDSS is one of Toyota's suspension black technologies, with its full name being Kinetic Dynamic Suspension System. It's commonly found in off-road SUVs like the Prado or Land Cruiser, allowing the vehicle to automatically adjust suspension stiffness on uneven terrain. For example, when driving on sand or mountain curves where the body tilts, the sensors immediately kick in to alter the suspension damping force, keeping the tires firmly planted. This not only provides a much more stable ride—no more feeling like your bones are rattling apart—but also helps prevent rollovers, especially during sharp turns. For maintenance, the hydraulic components may occasionally leak, so it's recommended to inspect them every two years to avoid any malfunctions affecting handling. With a KDSS-equipped vehicle, both daily commutes and adventures become more hassle-free, and tire lifespan is extended. Overall, this system makes driving more comfortable and safer, and I highly recommend it to friends who enjoy outdoor adventures.
