Lexus LX 570 Suspension Issues Explained (+Top 5 issues with Pro Tips)

In this brief article we are going to discuss the Lexus LX 570 suspension issues, what the causes are, and how these issues can be effectively dealt with.

Top 5 Suspension Problems in the Lexus LX 570

The 5 most common Suspension Problems in the Lexus LX 570 are:

  • AHC (Active Height Control) Unable to lift the vehicle to “HI” setting from ‘N’
  • Bouncy Ride
  • AHC does not change height & AVS does not change mode
  • Leaking Shock Absorber
  • KDSS Malfunction

What suspension does the 200 series Toyota Land Cruiser/ Lexus LX 570 have?

The Lexus LX 570 is based on the Land Cruiser 200 Series or J200 platform.

All the 200 Series Land Cruiser models had a basic coil spring suspension; the front suspension with a double-wishbone, independent and the rear suspension with driven-axle, five-link design. The front suspension was newly developed, replacing the previous model 100 Series torsion-bar independent layout. The rear suspension, on the other hand, was very similar to the previous 100 Series arrangement.

Apart from the above standard suspension set-up, the following Advanced systems were also available:

  • KDSS(Kinetic Dynamic Suspension System), was available either as standard or as an option depending on the model
  • 4-wheel AHC(Active Height Control suspension) with AVS(Adaptive Variable Suspension) were Optional features available in the European market

Does the Lexus LX 570 have air suspension?

No, the LX 570 did not come with an option of Air Suspension. It had a hydraulic suspension system with AHC ( Active height Control).

What are the problems in the Lexus LX 570 Suspension?

The most common suspension problems with the LX 470 are:

AHC (Active Height Control) Unable to lift from ‘N’ to ‘HI’

Symptoms:

  • When the vehicle is already in ‘Lo’ and ‘N’ is selected,  the AHC manages to raise. Lowering from ‘N’ to ‘Lo’ also functions.
  • When trying to move to the ‘Hi’ position, the suspension moves only by a minuscule amount.

Root Cause:

  • The Gas pressure/Fluid pressure seems to not develop beyond the ‘N’ position. There could be 3 possible reasons:
  • Similar to the Brake System, over a long usage period, there could be minor depletion of AHC Hydraulic system fluid. 
  • The “Gas Chamber” connected to the Height Accumulator may be malfunctioning
  • Either one or more of the 4 Height Sensors, located at each suspension corner, might be malfunctioning

Solution:

  • Check the Fluid level in the reservoir under the hood. If needed top-up with the OEM provided AHC fluid. Repeat the exercise of trying to select ‘Hi’ and seeing if the vehicle lifts itself.
  • In case the earlier measure did not work, then, Replace the “Gas Chamber” and check if the AHC functions.
  • In case the “Gas Chamber” replacement did not fix the issue, then try to either recondition or replace the “Height Sensors”

Bouncy Ride

Symptoms:

  • Ride quality seems bouncy even for very minor bumps
  • Shock-absorbers seems normal/newly replaced

Root Cause:

  • The vehicle suspension lift happens when the AHC Control system signals the “Gas Chamber and Damping Force Control Actuator” to increase the Nitrogen gas pressure in the Shock Absorber, leading to an increase in Shock Absorber length. So, normally the Shock-absorber would have been the first to blame. 
  • Since the shocks were already verified as properly working, the fault would most likely be with the “Gas Chamber” which ‘HOLDs’ and maintains the Gas Pressure. The Gas Chamber contains a membrane that produces pressure and this deteriorates due to wear and tear.

Solution:

  • Replace all 4 of the Gas Chambers after releasing the hydraulic pressure and bleeding the system. Once fitted, the system will need to be replenished with new Hydraulic Fluid and bleeded to eliminate air bubbles ( similar to brake hydraulics). 

AHC does not change height & AVS does not change mode

Symptoms:

  • Vehicle stays in ‘L’ ride height position
  • The AHC ‘off’ lamp blinks and the ‘L’ lamp is illuminated constantly. 
  • Pressing the AHC ‘off’ button does not change anything.
  • Changing the AVS suspension mode from comfort to sport makes no difference in feel. The suspension shock absorbers are stuck in a very stiff setting

Root Cause:

  • Use a scanner to check for Fault Codes.
  • The most probable errors you may get are : c1751 (continuous current to compressor) and c1762 (abnormal oil pressure to pump)
  • This clearly indicates a probable issue with the pump
  • You can check the pump by removing the control system connector and attaching a jumper wire into the diagnostics connector of the pump to manually test-run the AHC pump. If it does not manage to move any liquid, then it is clear that the pump is one of causes
  • You can also inspect the shock-absorbers for any oil stains and test the ‘Gas Chambers’ for pressure

Solution:

  • After inspecting the components mentioned above, start replacing the ones that were damaged/malfunctioning

Leaking Shock Absorber

Symptoms:

  • The Ride height may be either partially working or completely not working
  • Excessive bouncing during driving and doing a ‘Bounce’ test
  • Oil Stains on the Shock bottom tube

Root Cause:

  • Over time, the shock absorber seals and valves wear out due to ageing of Rubber/Polymer wear parts

Solution:

  • Shock absorber replacement with OEM part

 

KDSS warning light coming ON:

Symptoms:

  • KDSS yellow warning lamp comes ON
  • Other warnings may also be ON at the same time

Root Causes:

  • If all warning lights including ABS come on, then it could be a wiring issue. Try replacing the Driver-side and passenger-side ABS wiring connections
  • The external housing is designed for easy ventilation. It therefore also allows mud, salt and any other road debris to accumulate in the housing. This results in corrosion and then causes a Leakage in the stabilizer control housing assembly.
  • If the controller was not the issue, and you hear ‘Clunking’ noises from the suspension then it could be a case of low system pressure.

Solutions:

  • Apart from cleaning the underbody, you need to also periodically flush out the housing to prevent mud and or salt from packing accumulating in the area around the control assembly.
  • If you observed ‘clunking’ noises from the suspension, then you need to get the KDSS system tested for pressure. It should be closer to 3MPa. Any drop from that pressure means that it allows the ARB to move resulting in clunking noise as well. was below 3 Mpa, then the pressure needs to be corrected.

Conclusion

In this brief article we have discussed the Lexus LX 570 suspension issues, what the causes are, and how these issues can be effectively dealt with.

Frequently Asked Questions (FAQs): 

 

Is the Lexus LX 570 reliable?

Yes, the Lexus LX 570 is indeed a very reliable vehicle. As per ‘RepairPal’, the Lexus LX570 Reliability Rating is 3.5 out of 5.0. This puts the LX 570 in the 9th position out of a comparison of 30 luxury cars of a similar price range.

 

How long will a Lexus LX 570 last?

A Lexus LX 570 can last up to 500,000 miles or upto 25 years, if maintained properly.

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