I know there are plenty of forum posts about the air suspension in the 3rd generation LS ultra luxury edition. I have a 2003 LS 430 UL and I recently hit the button to raise the suspension (for no reason at all) then I lowered it. I didn't notice a difference. The next day, I noticed the back right is slammed to what seems to be the bottom. I tried hitting the button to raise the car again and I don't see a difference, so I lowered it again.

I tried driving the car and it now always goes to the right. Is this due tot he suspension? What should I look out for before I bring it to a mechanic?

 

Sounds like a bad strut, but when I first got my car, the ride height button did not work and I didn't know (it just did nothing, not even giving a dash message like Height Hi) until my cruise computer failed (a common issue in 2005s apparently). When I brought it in dealer diagnosed (scanned) and fixed both issues. It turns out the hight button was because one of the rear ride height sensors was bad. Good thing car was certified. The sensor is not cheap but is much cheaper than a strut, if I recall. Several hundred $ at dealer but warranty covered it. Could it be that with you?

 

Hmm I don't think it's that cause everything else in the car seems to work. I just tried going to high again and I got the message "Height Hi"

 

Defective height sensors (any of the 2 front and 2 rear) could cause this. Since your back right is slammed, the likely problems are front left height sensor, rear right height sensor, or the rear right pneumatic cylinder.

If you plug in Techstream (or take it to a Lexus/Toyota dealership or an independent mechanic who specializes in Lexus/Toyota), you can check the readings of the height sensors in the data list, and with the car running, you can active test the suspension and send raise/lower commands to each pneumatic cylinder individually.

Don't bother taking the car to a regular mechanic - without Toyota-specific software and special service tools, a run of the mill mechanic will not be able to help, or will take a lot of time to figure it out and charge you for this time.

 

Thanks for the response. I was thinking of buying a Techstream CD off ebay but even if I do realize it's the height sensor, I probably can't do the work myself. Any idea how much this might cost at dealership vs Toyota mechanic? Or is the work easy enough that any amateur DIYer can do it?

Also, I mentioned that the car kept veering right, today I noticed that the front right tire is flat so that is probably the cause and not the suspension.

 

The height sensors are easy enough to change yourself. Aftermarket sensors can be found on Aliexpress for ~$15-25, much cheaper than the actual Lexus sensors (for my 2002, the part numbers are RR 89407-50060 and RL 89408-50060) which are closer to $500 each. You should be able to use the same sensor on both sides, most aftermarket parts just list the Rear Left part number.

However, you should use Techstream to confirm which one is defective, if any, before replacing them. Whenever there is any air suspension trouble code stored in the computer, the multi-information display will show HEIGHT HI and there will be a C17xx code, extractable using an OBD2 code scanner that can pull Lexus/Toyota codes.

The sensor is basically a potentiometer that turns based on the movement of the arm attached to it, and it doesn't turn much, so it is sensitive to small movements and has a very small operating range. According to what someone at the Lexus dealership told me several years ago, be careful not to move the sensor past its normal operating range or you will damage it.

Diagnostic charge at Lexus/Toyota for anything is usually 1 hour of labor, labor rates generally range from $55-145/hr. Lexus and Toyota are essentially the same company and share the same software and shop tools/parts, so if a Toyota dealership says they can do whatever you need, it'll come out slightly cheaper (and slightly slower if they need to order in Lexus-specific parts) than if you go to a Lexus dealership.

 

Strange. Even before I had a chance to buy the techstream software, I drove the car around and the back right seems to be raising up slowly. Now the back left is lowered but I can still fit 3 fingers between the tire and the car. Rear right I now fit 2 fingers (as opposed to 0). And the front I now fit 5 instead of 4.

 

Thank you so much.

It is air suspension.
Sorry excuse the ignorance, how do you detect the leak as suggested?

Oro, it is a great place hey! Unique and special!
Lovely to hear you have visited!

 

Sounds like the back right strut failed and is not holding air. The compressor is able to pump air in and raise the strut, but the air doesn't hold. The leak is inside the rubber bladder inside the strut.

 

I had one leaky shock in front and one in back, meaning I was facing a huge replacement bill. Air shocks are over$1k each heavily discounted. I decided to replace the entire air shock suspension with LS430 coil overs. IIRC, parts ran about $3k plus about $1.8k labor. I didn’t bother to replace leaky sensors…just leveled the car with headlights on and pulled the compressor, height, and AFS fuses. You still need height sensors if you want AFS.

 

The OEM air struts can be had for $600-$800 each from Japan

 

Thanks so much!

 

Here are my two videos on the subject, along with some other odd maintenance items.

 

WOW, thanks so much!!!
Should be with the mechanic this week, will keep you updated!

 

I had a leak in one front and one rear strut. Ended up replacing all 4 with OEM coils/struts from the ML model. The height sensors are still needed for AFS. Since mine went bad, I leveled the car, then pulled height and AFS fuses. I have the full P/N list if anyone wants it.