Toyota Landcruiser URJ202 2012 bumpy ride and uncomfortable

[saikatsaha]

On my 2012 Toyota Landcruiser ZX UTJ202 I feel every little bump on the road. The comfort and stability is not how it is supposed to be. The ride feels floaty bumpy and squirrely. For comparison I took a test drive in a 2017 Landcruiser ZX and felt a night and day difference. After all the research I did the following:
I visually inspected the shocks and AHC lines but found no leak.
I took the rear bumper cover off and that made it easy to see the graduation markings on the fluid reservoir. I then tested the graduation markings test from L to H and got a reading of a little over 5.
I flushed the fluid with new 5 liters of AHC fluid. The old fluid was dark.
While I was flushing the fluid I have also replaced each accumulator globe , suspension control accumulator assembly . Did fluid bleeding 6 times .
After the flush I went for a test ride but felt no change in ride quality at all. It felt like car is on Coil over and damping is so stiff . H -N - L works perfectly .
So now I am at a point where I don't know what should I do next.

 

[PDoyle]

I'm thinking you need new struts.

 

[saikatsaha]

I'm thinking you need new struts.

Thank you for replying . But in 200 series there is no struts .

 

[PDoyle]

My apologies. I mean shocks. That would be the next thing I would be thinking of replacing. How many miles? Maybe springs too.

 

[grinchy]

What’s your vehicle weight? What size tires are you running? What is you tire pressure?

 

[lx200inAR]

Also, do you know if your AHC sensors have been adjusted to lift the vehicle at N height, to higher than stock? Or i suppose lower as well. If on stock wheels/tires, what height is it from ground to fenders? Might compare to the thread recently started to see if you are at stock adjustment or not.

 

[saikatsaha]

My apologies. I mean shocks. That would be the next thing I would be thinking of replacing. How many miles? Maybe springs too.

i have checked the shocks, there is now sound or any unusual obstacles . Springs also seems fine . 68k km now in odometer

 

[saikatsaha]

What’s your vehicle weight? What size tires are you running? What is you tire pressure?

I didn't put any extra weight in the car . Tires size is stock 20 inch . i always keep tire pressure 35psi .

 

[saikatsaha]

Also, do you know if your AHC sensors have been adjusted to lift the vehicle at N height, to higher than stock? Or i suppose lower as well. If on stock wheels/tires, what height is it from ground to fenders? Might compare to the thread recently started to see if you are at stock adjustment or not.

we don't have toyota dealer in out country . Our local mechanic flushed the oil and changed the Accumulator . we have followed the toyota global services instructions. Also maintained the same height according to gsc recommendation .
But i am doubting the

Also, do you know if your AHC sensors have been adjusted to lift the vehicle at N height, to higher than stock? Or i suppose lower as well. If on stock wheels/tires, what height is it from ground to fenders? Might compare to the thread recently started to see if you are at stock adjustment or not.

Also, do you know if your AHC sensors have been adjusted to lift the vehicle at N height, to higher than stock? Or i suppose lower as well. If on stock wheels/tires, what height is it from ground to fenders? Might compare to the thread recently started to see if you are at stock adjustment or not.

we don't have toyota dealer in out country . Our local mechanic flushed the oil and changed the Accumulator . we have followed the toyota global services instructions. Also maintained the same height according to gsc recommendation .
But i am doubting the mechanics did something wrong with the height sensor . i searched everywhere to know whats the uses of active height sensor in the AHC system . How to adjust the damping ? what's actual parameters of height sensor controls ?

 

[lx200inAR]

we don't have toyota dealer in out country . Our local mechanic flushed the oil and changed the Accumulator . we have followed the toyota global services instructions. Also maintained the same height according to gsc recommendation .
But i am doubting the


we don't have toyota dealer in out country . Our local mechanic flushed the oil and changed the Accumulator . we have followed the toyota global services instructions. Also maintained the same height according to gsc recommendation .
But i am doubting the mechanics did something wrong with the height sensor . i searched everywhere to know whats the uses of active height sensor in the AHC system . How to adjust the damping ? what's actual parameters of height sensor controls ?

There are 4 height sensors physically connected to the suspension between upper control arms and frame. These are how the suspension ECU measures the height of the suspension. It's a common modification to adjust the sensors (physically adjusting them from under the truck) to "trick" the suspension ECU into raising the truck up to a new taller "N" height.

My thoughts are possibly that your "N" height may be off, causing your suspension to be different than stock. If sensors are adjusted high/low, no amount of changing fluid or accumulators would affect that. I'll add though, many people raise their trucks using the sensor mod and say the truck still rides fine.

Also, my truck definitely acted the way you described when I had air in the hydraulic system. Doing a thorough bleeding may be your next step. If when you bleed, you get a lot of "milky" looking fluid (ahc oil mixed with air bubbles), I would do a thorough bleeding until you have a minimal amount of the milky looking fluid.

 

[grinchy]

I didn't put any extra weight in the car . Tires size is stock 20 inch . i always keep tire pressure 35psi .

ok. I ask as underinflated tires can have a very similar feel on AHC. Its not likely that P metrics at door card PSI would feel this way. Are you on P285/50r20 then?

 

[saikatsaha]

There are 4 height sensors physically connected to the suspension between upper control arms and frame. These are how the suspension ECU measures the height of the suspension. It's a common modification to adjust the sensors (physically adjusting them from under the truck) to "trick" the suspension ECU into raising the truck up to a new taller "N" height.

My thoughts are possibly that your "N" height may be off, causing your suspension to be different than stock. If sensors are adjusted high/low, no amount of changing fluid or accumulators would affect that. I'll add though, many people raise their trucks using the sensor mod and say the truck still rides fine.

Also, my truck definitely acted the way you described when I had air in the hydraulic system. Doing a thorough bleeding may be your next step. If when you bleed, you get a lot of "milky" looking fluid (ahc oil mixed with air bubbles), I would do a thorough bleeding until you have a minimal amount of the milky looking fluid.

Thank You for your reply & sorry for late reply .

I agree with you . Local mechanic may be did some thing wrong with the height sensor and ECU getting wrong input . I have already did bleeding 6 or 7 times . There is not bubbles in the fluid .

Now need to adjust the height sensor . Can you please help me with some suggestions on adjusting the height sensor .

Thanks in ADV.

 

[saikatsaha]

ok. I ask as underinflated tires can have a very similar feel on AHC. Its not likely that P metrics at door card PSI would feel this way. Are you on P285/50r20 then?

Yes Dear.

 

[lx200inAR]

There isn’t a ton to go wrong there. The sensors have about 1.5” of adjustment range. I’d check them all, make sure they are connected and close to the middle of the range. If that is the case already, then I’d get Techstream and make sure they are all reading similar height. Might include a picture of your truck here when in N mode. We might be able to deduce if you have a “sensor lift”.

You can check the forum for AHC lift threads to get all the pictures and how tos you would need to identify them.

 

[TeCKis300]

I would first suspect the globes. And it may have been that originally but I'm going a different direction as it seems like AHC has been freshened up with globes and fluid, and now is in working order.

Suspecting a follow-on installation issue.

Can you confirm that the suspension, particularly the front LCA alignment adjuster bolts were torqued only after the car was fully down on its tires? This really is to include all bushings like the shocks, and other suspension links. Many mechanics unknowingly torque major links while the truck is on the lift and in full droop. It's particularly a problem with the 200-series as it has such huge travel. Causing the bushings to bind at ride height and interfere with suspension performance.

 

[Sandroad]

Maybe some ideas in this sticky thread?

LX570 AHC “Basics” - Added as sticky thread for AHC Issues

Point of this thread is to serve as a repository for 200-series AHC info, including LX570 and LC equipped with AHC (in select global markets). Let’s begin with a theory. The 200-series LC (without AHC) and the LX570 (or LC with AHC) are like New York & LA. LC “purists” are like New Yorkers...

forum.ih8mud.com

 

[saikatsaha]

There isn’t a ton to go wrong there. The sensors have about 1.5” of adjustment range. I’d check them all, make sure they are connected and close to the middle of the range. If that is the case already, then I’d get Techstream and make sure they are all reading similar height. Might include a picture of your truck here when in N mode. We might be able to deduce if you have a “sensor lift”.

You can check the forum for AHC lift threads to get all the pictures and how tos you would need to identify them.

Sorry Dear for late reply . Workshop was close due to unavoidable reasons . I took pictures of 4 height sensors also the car . we dont have any knowledge on adjusting the height sensor and also the parameters of 4 height sensor . There is another important point is Right / left front height adjustment - i also dont have any knowledge about it . i have added the present conditions pictures . Please help me with directions , suggestions if you have information . Thanks .

 

[saikatsaha]

There isn’t a ton to go wrong there. The sensors have about 1.5” of adjustment range. I’d check them all, make sure they are connected and close to the middle of the range. If that is the case already, then I’d get Techstream and make sure they are all reading similar height. Might include a picture of your truck here when in N mode. We might be able to deduce if you have a “sensor lift”.

You can check the forum for AHC lift threads to get all the pictures and how tos you would need to identify them.

Here the height sensors data on Height N .

 

[saikatsaha]

I would first suspect the globes. And it may have been that originally but I'm going a different direction as it seems like AHC has been freshened up with globes and fluid, and now is in working order.

Suspecting a follow-on installation issue.

Can you confirm that the suspension, particularly the front LCA alignment adjuster bolts were torqued only after the car was fully down on its tires? This really is to include all bushings like the shocks, and other suspension links. Many mechanics unknowingly torque major links while the truck is on the lift and in full droop. It's particularly a problem with the 200-series as it has such huge travel. Causing the bushings to bind at ride height and interfere with suspension performance.

I have checked this with mechanics , they did it while the car was on lift .

 

[lx200inAR]

Nothing in your Pictures looks like it should be affecting your ride terribly. I’d go down the path @TeCKis300 suggested.