Toyota KDSS Suspension Problems

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Toyota KDSS (Kinetic Dynamic Suspension System) has gained significant popularity among off-road enthusiasts and adventure seekers for its ability to enhance vehicle stability and articulation on rugged terrains. However, as with any innovative technology, there have been reports of potential problems associated with the KDSS system.

One common problem associated with the KDSS is leaning the vehicle after suspension modification. Another issue that has been reported by Land Cruiser owners is a malfunctioning KDSS warning light. 

Don’t worry. Here we’re to provide a comprehensive understanding of Toyota owners’ challenges and offer guidance on addressing these problems effectively while ensuring a smooth and reliable driving experience.

What is the Toyota KDSS Suspension System?

To get rid of any issue, you should have a good grasp on the subject, matter, or thing. So, let’s first introduce the KDSS suspension system. The Kinetic Dynamic Suspension System (KDSS) is Toyota’s Adaptive Suspension system, which serves as an enhancement rather than a completely separate suspension system. 

KDSS comprises two hydraulic pistons connected to the front and rear sway bars. While primarily designed to improve off-road wheel articulation, KDSS also ensures optimal traction, stability, and body roll control during on-road driving. 

In essence, KDSS offers a balanced combination of off-road capability and on-road performance. KDSS, as its name implies, is precisely engineered to respond dynamically to external forces exerted on the suspension system. 

This ensures optimal chassis performance, regardless of whether it is driving on paved roads or off-road terrains. This is achieved by employing an electronically controlled network of hydraulics to adjust or deactivate the anti-roll bars. 

Common Toyota KDSS Suspension Problems

Toyota KDSS Suspension Problems

KDSS Lean After Modification

One of the most common concerns regarding Toyota KDSS suspension is experiencing a noticeable lean after fitting a modified suspension. In many cases, enthusiasts opt for aftermarket lift kits not specifically designed to be compatible with KDSS systems. 

This can result in uneven weight distribution across the vehicle, leading to one side sitting higher than the other and causing a noticeable lean. Even after attaching the suitable kit, this problem can also arise. 

Installing a lift kit may result in the vehicle tilting towards the driver’s side (where the KDSS system is located) as it alters the suspension’s geometry and raises the position of the hydraulic piston within the cylinder. Additionally, incorrect adjustment or insufficient tightening of sway bars can exacerbate this issue. 

Possible Solution

First, the distance between the bottom of the wheel and the bottom of the guard on each side of the vehicle should be measured and recorded. The KDSS valve box between the muffler and the chassis on the left side should have its two shutter valves loosened by a maximum of 3 turns using a 5 mm Allen key. The vehicle should then be parked on a hard, level surface. 

A 75 mm-high piece of wood should be placed in front of or behind the left rear tire. Alternatively, a jack can be placed under the left rear axle housing to raise the tire approximately 50 mm off the ground. Afterward, return to the KDSS valve box and re-tighten the two shutter valves using the 5 mm Allen key.

After driving the vehicle off the wooden piece, measure the distance between the wheel and the guard on both sides. 

  • If the measurements differ by less than 10 mm, you have completed the task. 
  • If the vehicle is still leaning, albeit by a smaller amount, you can repeat the procedure but use a higher object to drive onto, such as 100 or 125 mm, or raise the axle with a jack. 
  • However, if there is no improvement, installing a strut spacer or longer springs on the right side of the vehicle may be necessary. Alternatively, there could be a leak or malfunction in the KDSS system. 

In any case, having a suspension specialist familiar with the KDSS system is recommended to assess your vehicle.

Front End Clunk Noise 

Owners of Toyota vehicles equipped with the Kinetic Dynamic Suspension System (KDSS) have reported a front-end clunking noise issue that has caused drivers’ concerns.  

The front-end clunk noise issue has been observed in various models, such as the 4Runner, Land Cruiser, and GX460, all featuring the KDSS technology. Owners have described the noise as a loud thud or knocking sound that can be felt through the steering wheel and floorboard. 

One possible cause of the front-end clunk noise issue is worn or damaged suspension components. Over time, the constant movement and stress on these parts can lead to wear and tear, resulting in loose or damaged components that produce abnormal noises. 

When the bushings become worn or loose, they may fail to adequately absorb impacts and vibrations, resulting in an audible clunking sound during driving maneuvers. Another potential cause of the front-end clunk noise issue is related to the stabilizer link assembly.

Possible Solution:

Firstly, it is essential to diagnose the root cause of the problem accurately. So, inspect all components of the KDSS system for any signs of wear or damage. Pay close attention to bushings, mounts, and linkages connecting different suspension parts. 

Once you have identified the source of the noise issue, proceed with checking all associated parts thoroughly for any signs of damage or wear. Any worn-out or damaged components should be replaced promptly to eliminate potential noise sources. 

Besides, make sure all bolts and fasteners are properly tightened. Loose bolts can cause vibrations and clunking noises in the vehicle’s front end. Use a torque wrench to ensure everything is tightened according to the manufacturer’s specifications.

Warning Light Issue

The warning light of the Toyota KDSS suspension system is designed to activate when there is a problem with the suspension system, alerting the driver to take appropriate action. 

If all warning lights, including ABS, illuminate, it is possible that there is a problem with the wiring. Consider replacing the ABS wiring on both the driver-side and passenger side. 

The external housing is designed to facilitate proper ventilation, but it also allows for the accumulation of mud, salt, and other debris from the road. As a result, corrosion may occur and lead to a leakage in the stabilizer control housing assembly. 

If the controller is not the source of the problem and you notice clunking noises from the suspension, it may indicate low system pressure. This issue pertains to Toyota KDSS suspension warning lights. Please maintain a professional tone when addressing this matter.

Possible Solution

First, you have to clean the underbody. Besides, it is necessary to periodically flush the housing to prevent the buildup of mud and salt around the control assembly. If you notice clunking noises coming from the suspension, it is important to have the KDSS system tested for pressure. 

The pressure should ideally be around 3MPa. Any decrease in pressure indicates that the ARB can move, resulting in clunking noises. If the pressure is found to be significantly below 3 MPA, it must be adjusted accordingly. This pertains to the warning light issue with the Toyota KDSS suspension.

Final Words

While the Toyota Kinetic Dynamic Suspension System (KDSS) has been widely praised for its ability to enhance both on-road comfort and off-road capability, it is not without its issues. 

As a responsible owner, it is crucial to stay informed about any recalls or updates related to the KDSS suspension system and to promptly address any issues with your vehicle. By doing so, you can ensure a safe and enjoyable off-roading experience.