Ls430 '01 Ultra - Air Suspension Stuck On High

[Jacks]

Hi All,

I have a 2001 LS430 Ultra with 105K. Right now the air suspension compressor appears to be on constantly to all four wheels. This car is riding high and if I can't fix it maybe I'll just buy 22" wheels I have manually disconnected the height sensors on the rear with no luck (very easy, harness wire is right behind tire). I have manually adjusted the rear settings... No Luck. I have pulled the fuse on the compressor.. no luck, as I don't know where to bleed the air out. I believe my struts are fine as the car won't lower after many days in the garage, hence no air leakage. Any knowledge/ideas about this system or the location of the compressor or bleed valves would be greatly appreciated.

My fear is if I don't get this shut off, somethings going to burn out, break or start leaking.

The dealer already said they will start with the two rear height sensors ($420 each no labor). I explained, I believe it's the compressor switch as I have already tried running the car with the height sensors disconnected from the wire harness. They responded to bring it in and they will start trouble shooting at $120 hour. :cries: Yikes.

Thanks for any input.

Jack

[Brooklyn Digital]

hay there,

bring the car to toyota dealer and see what they say

[SKperformance]

Hmm , i would start by either buy a subscription to the Lexus online manuals or just buying them as you sound very mechanically aprt , it will give you a break down of which parts to check and replace. You may have a purge valve issue.

[SKperformance]

On my 98 -00

The compressor should be located in front of the right front wheel behind the bumper also the release valve for the front is located there also. The rear release valves are in the right side of the trunk.

Do you hear the compressor running at all>?

Hope it helps.

I would try and find out if there is an pressure sensor which may be faulty causing the system to think it is under inflated and running the compressor to get it up to the right psi.

[jpilk99]

Hi All,

I have a 2001 LS430 Ultra with 105K. Right now the air suspension compressor appears to be on constantly to all four wheels. This car is riding high and if I can't fix it maybe I'll just buy 22" wheels I have manually disconnected the height sensors on the rear with no luck (very easy, harness wire is right behind tire). I have manually adjusted the rear settings... No Luck. I have pulled the fuse on the compressor.. no luck, as I don't know where to bleed the air out. I believe my struts are fine as the car won't lower after many days in the garage, hence no air leakage. Any knowledge/ideas about this system or the location of the compressor or bleed valves would be greatly appreciated.

My fear is if I don't get this shut off, somethings going to burn out, break or start leaking.

The dealer already said they will start with the two rear height sensors ($420 each no labor). I explained, I believe it's the compressor switch as I have already tried running the car with the height sensors disconnected from the wire harness. They responded to bring it in and they will start trouble shooting at $120 hour. :cries: Yikes.

Thanks for any input.

Jack

---------------------------------------------------------------

Hi Jack,

Obviously, some time has gone by since your issue - but I believe I'm having the same exact one on my 2004 LS 430 Ultra. Actually, I think it's only the rears that are over-pressurized and both sides of the rear are about 2 or 3 inches too high. Plus, driving at anything more than 5 or 10 mph and it's bouncing all over the place.

Did you get the answer on how to fix?

Thanks so much for any help you can lend. I can't afford a big "Lexus" repair.

[jpilk99]

Hi All,

I have a 2001 LS430 Ultra with 105K. Right now the air suspension compressor appears to be on constantly to all four wheels. This car is riding high and if I can't fix it maybe I'll just buy 22" wheels I have manually disconnected the height sensors on the rear with no luck (very easy, harness wire is right behind tire). I have manually adjusted the rear settings... No Luck. I have pulled the fuse on the compressor.. no luck, as I don't know where to bleed the air out. I believe my struts are fine as the car won't lower after many days in the garage, hence no air leakage. Any knowledge/ideas about this system or the location of the compressor or bleed valves would be greatly appreciated.

My fear is if I don't get this shut off, somethings going to burn out, break or start leaking.

The dealer already said they will start with the two rear height sensors ($420 each no labor). I explained, I believe it's the compressor switch as I have already tried running the car with the height sensors disconnected from the wire harness. They responded to bring it in and they will start trouble shooting at $120 hour. :cries: Yikes.

Thanks for any input.

Jack

---------------------------------------------------------------

Hi Jack,

Obviously, some time has gone by since your issue - but I believe I'm having the same exact one on my 2004 LS 430 Ultra. Actually, I think it's only the rears that are over-pressurized and both sides of the rear are about 2 or 3 inches too high. Plus, driving at anything more than 5 or 10 mph and it's bouncing all over the place.

Did you get the answer on how to fix?

Thanks so much for any help you can lend. I can't afford a big "Lexus" repair.

[Jacks]

Sorry to hear and I do not have a happy answer.

Here is what I found out.

There are two sensors in the rear by each wheel that sense the heigth. These two sensors are relatively low quality and let moisture in. Eventually it fries the sensor out and you ride high all time. I escalated the process cause I washed the car a lot and the car wash I used had one of those high pressure underbody flushes.

The dealer seems to be very aware of the problem when I talked with them over the phone. Considering it's solid state electronics, your just pretty screwed when it goes. The sensors look pretty easy to replace if the scews aren't rusted on, and you don't have to cut them off. Mine were so I had the dealer do it. The sensors in Milwaukee sold for about $350 each and $75 for installation each. I did both and the total job was around $800.

I bit the bullet, spent the money and the car is now back to that creamy smooth ride.

Wish I had better news.

Good luck.

[curiousB]

ditto on the poor quality. I have ride height on front and rear left axles used for the AFS light level adjustment system. Rear sensor went bad similar to yours and lights then were pointed downward. I replaced sensor myself but part was about $400!!!! Part is not hermetically sealed and would probably benefit from a simple splash shield to reduce moisture hitting it. In my case bearing seized due to corrosion of turning point. Didn’t see a lube instruction on routine maintenance lists. Maybe a shot of aerosol lubricant every oil change would give bearing a better life. Otherwise I expect I’ll be buying another sensor in 40-50k miles from now.

Anyway since learned part is available at www.parts.com fopr about $100 cheaper so will know better for next time.

Someone posted earlier that they tested sensor by disconnecting it. That really isn’t as valid test as the ECU for ride height will likely detect this as a faulty sensor and go into a failsafe condition. In this case it looks like max height is the fail safe mode.

[jpilk99]

Thank you both for your help. I guess this is probably a designed failure/service enabler. Obviously, ANYTHING underneath a car is going to get desimated by sand, water, salt (likely), and all kinds of other abuse. I've been under the car a bunch, (unplugged both sensors hoping that would do it), and can see that they're just cheapoh switches - NOWAY they should cost more than $10. Oh well, it is what it is.

The one other thing, now that I think about it, that has me concerned is: What's the likelihood that BOTH failed at the exact same time - because both driver's and passenger's side is 'failsafed' at max pressure? You know what I mean? If a sensor went bad, then just that side would be max'd out; wouldn't you think?

Oh well, at least I feel I'm a lot closer to the problem. Now I just have to come up with the coin to buy them for between $600 - $800, buy a funky reverse-torque bit socket, hope they're not too rusted, and swap em' out.

Ah well, at least I'm above ground!!!

Thanks again folks.

Jay Pilkington

[curiousB]

I would doubt both failed at same time. The odds of that seem pretty remote. If you have a DVM you could measure the device to see what resistance each is.

Procedure would be to measure resistance from one end of potentiometer (POT) to the other and see it is proper value and not open circuit. Then measure from wiper to one end of the pot and watch resistance value change as you move control arm from one end to the other. You want to be sure there aren't dead spots where you lose a reading because of worn out portion of carbon path inside POT. Other failure is just the arm is frozen due a seized bearing and won't move but that is obvious to inspect.