pyr8

My rear end is sitting at the lowest point it can.

I stopped my car yesterday (Car running) to run a quick errand. When I returned to my car 3 minutes later, the rear end of the car was slammed to the ground.

I have already run a diagnostic and I am not throwing any codes according the the ECU.

The front end is sitting high, and the rears are low, however they rears are sitting at equal level.


The other thing to mention is that I generally hear the compressor come on when I first start my car, however it is not activating as far as I can tell....

Is it a sensor issue or a compressor issue???

If its a compressor issue, is there a way to test it?

Yamae

Both left and right?
If so, there is one item to be checked?

pyr8

Both left and right (rear) shocks are sitting at the same level...they both lost air equally when it happened!

Since my original post earlier, I have removed the right side wheel-well cover to check the suspensions air compressor.

I am not getting any voltage across the + positive & - negative wires that connect to the compressor.

There is a second connection at the bottom of the compressor unit (solenoid) and when I connect and disconnect the plug, I can hear the solenoid activating.

I am assuming now that because I am not getting voltage to the compressors terminals, its an issue with the suspension ECU not sending voltage to the compressor?

Lastly, I inadvertently disconnected one of the air hoses on the front of the car that sends air to each of the shocks on the front, now my left and right fronts are sitting slammed on the ground.

I have lost all air to the suspension and the compressor wont kick on....sigh!

pyr8

Thanks for posting back Yamae...what "Item" should I be checking?

Yamae

So both L and R are equally bottomed down. Sounds like the bags are OK to me but the pressure is not applied to both of them. It probably means that the air is not supplied to the rear control valve or leaking. Sometimes the valve itself is not working. The attached drawing is for a JDM but I believe it can help you some.

I'd check the valve whether it's getting the air monitoring at the point where the red * is indicated. it is the entrance of the pressurized air from the pump via the valve for the front. Be careful for the high pressure air when you check it. You must wear an eyes protector. Black arrows →are indicating where you need to check the air leaking.

Since you have already run a diagnostic and the ECU is not throwing any codes, I don't write any about it but I wonder how did you check the ECU for the air suspension. It is totally different from the main ECU for the engine and the AT.

pyr8

Yamae, I found the issue.

The rear left ride height sensor lower ball-joint completely seized solid and caused the threaded adjustment screw to snap off. The sensor arm was just hanging there.

Time to put an order in with Lexus.

P.S., I live in Canada but have a 95 JDM Celsior.

By the way, thank you for actually replying... your willingness to assist me is very much appreciated!

saleenssc

Glad you figured out your problem. Just a quick question. How can i tell if an Ls400 has air suspension? I have a fairly new to me 98 LS400.

thanks

pyr8

Do you have a "Ride Height" button on your center console?

If not, you don't.

saleenssc

I do not have a ride height button. Thanks for taking the time to respond And clearing that up for me.