Air suspension, rear wheels will not respond

[Papagut]

Hi, I have an interesting issue: my front wheels will adjust ride height, but my rear wheels will not - they are stuck in the highest position. When I start it up, I can hear the system attempt to raise the back end further, but since it is at it's maximum, this causes a system error eventually that locks out any manual adjustment.

 

I suspect that this started when I did an extended job on this car and the right rear had a slow leak in the system someplace, and eventually dropped down to a very low position. What I thought I would find is that the height sensor on that corner may have broken - but no, all looks fine (sensors at all corners look fine). 

 

When first start the car, the height adjustment is active momentarily, and if I adjust it, the front wheels will respond - the rear wheels will not. My first instinct was to calibrate with Durametric, but that requires the suspension to be in the normal position, and I cannot get there with my back end stuck way up in the air.    

 

It is as if air can enter the rear end but cannot escape, or that the vehicle believes that the rear end is in a lower position than it is in reality. 

 

Any suggestions on how to proceed? 

 

Thanks, Mark

Edited July 22, 2015 by Papagut

[wrinkledpants]

I've read about others having a similar issue, and they crack the air hose on the strut to manually lower the car down to a reasonable position.  

[Papagut]

Strangely, I was wondering about giving that a try - I have the cover off at the compressor and will give it a shot and post back 

[paqueras]

Exact same problem here.

I went to the car wash and i forgot to turn off the leveling system and now my rear wheels are stuck!

Please help!!!

[paqueras]

Problem solved!

You just have to purge some air from the rear struts as wrinkledpants explained. Just follow the hose that goes to each strut and using a 12mm wrench un-screw the bolt and the air pressure will come out. Use jacks and stands for safety. After you lowered the rear, the air suspension will find itself.

Good luck!

Edited July 31, 2015 by paqueras

[Papagut]

So, in the end I never got to try this solution... There was a HUGE storm in Calgary, flooding everywhere, and I was caught in it. I had to drive through mabye 24" of water at one point. It was something else! Anyhow, I park it for the evening, and when I go to fire it up the next morning - problem solved! Something obviously happened on that trip that caused it to reset in some way - but as soon as the back end dropped, it returned to level and is functioning normally.

 

So, if you find yourself in the situation I did, I would definitely try bleeding off some air like wrinkledpants and paqueras are suggesting before replacing the module or valve body, which are pretty expensive.

 

Or of course, just drive into the nearest lake - that clearly seems to work!

 

Thanks,

Mark

[BOOSTTT]

I had a similar issue after unplugging the battery and installing fuel pumps on a fairly pitched down driveway.  Before I put all my stuff away, I started the 04 Cayenne Turbo, and all my wheels were at rediculously different levels and my Durametric could not read my values, as usual....Durametric is a pain to use for adaptation to suspension btw.  The rear was jacked up and it had a major tilt to the driver's side.  After lots of hours trying to get my faulty suspension light to go off with getting the Durametric values equal, I did get the light off, but still jacked up and leaning to the side, but no dash warning lights.  I released pressure from the highest wheel...rear Rt. and nothing came out.  no air pressure, but I did pull the fuse b4 jacking her up.  I took off the sensor with major problems with the sensor screws...rusted in, but with PB Blaster, I was able to loosen it and move it around.  I then used my favorite tool.  I lightly tapped the sensor with a hammer to "hopefully" allow whatever was stuck to release.  I dropped her down, plugged in the fuse, and to my dismay, she is almost perfectly level now.  At first the Durametric would not accept any values on the front, but I tried a trick.   I jacked up the front just to where I thought it looked right.  I could just fit my open hand above the wheel and fender.  I started typing in values, and they were accepted this time quickly.  Of course, you have to get all new values saved or it will not complete and you will have a warning.  I have not read about anyone else doing this, but it worked for me after about a wk of messing with the Durametric values.  I hope this could help someone with my similar issues.  Seems really common.  I think I'm going to need a new level sensor.  I also did the air compressor O-ring replacement and that speeds up the leveling for sure.  Got it from United Kingdom on ebay for around 20 Dollars.  Works really well.  Easy job.  Just drop the bracket.  No need to take the pump out or remove any hoses.

Cheers!