# "Level Fault - Workshop!" Message



## planeadam (Nov 26, 2011)

Hello all,

My 2004 Phaeton with a little over 100k miles on it has been giving me a problem with the air ride suspension. When starting the vehicle, a "Level Fault - Workshop" message is displayed on the instrument cluster, and the car has been slowly sinking as the air ride (I presume) slowly deflates. Around 10,000 miles ago, I had a problem with the suspension, but that time the car immediately and actively sank; this was solved by replacing the air ride computer (it is the B, not C-type). I've tried replacing the computer with another B-type computer, but to no avail. The local VW dealer and an independent import car garage have told me some things, and I would like to learn more about this problem and possible ways to try and solve it.

1. I have been told that no voltage is making it from the computer to the left front sensor. Dealer says its the computer, but could this possibly be the wiring harness or a bad connection? If so, how do I get into the wheel well in order to test this hypothesis? My best guess is it isn't the computer, as the car never actively sank (this happened when the original computer went bad).

2. I have also been told that the right rear sensor is bad. Is this a part I can replace with a modest amount of auto knowledge? I do my own oil, replace brake pads/rotors, etc. If so, does anyone have a drawing/maintenance manual parts list available? 

3. I have heard conflicting reports as to a freshly-ordered sensor being and not being compatible with the B-type computer. Dealer told me new sensors will only speak to a C-computer; independent garage told me new sensors will speak to my B computer. Who is correct? 

From a few hours of internet browsing from the first instance and this second instance of failure, it seems this is a somewhat common issue with the 2004 Phaeton. I'd greatly appreciate any information on how to solve this problem. Thanks a bunch!


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## Jxander (Aug 5, 2008)

You may want to start by looking at the Self Study Programme for the Phaeton's air suspension. It is a three part pdf document and can be found at the following link.

http://www.volkspage.net/technik/ssp/index3_eng.php

I assume your dealer or tech has scanned your Phaeton for diagnostic error codes. Before proceeding, I would make sure you are basing your efforts and dollars on good diagnostic info. The Phaeton has a fantastic diagnostic system built in. All that is needed to extract that info is a VW diagnostic computer or VCDS(Vagcom) sold at retail by Ross-Tech. Many VAG owners have purchased the Ross-Tech diagnostic system. If your dealer is correct regarding a level sensor or sender being faulty, you might try, prior to replacing the sender unplugging it and cleaning the connection good. It is under the vehicle and exposed to the elements. 

The only thing bothering me is that you note that the vehicle slowly lowers as if system is losing air. That would suggest to me an air leak somewhere. Have you checked the air lines running under the car and down the sides of the car. There have been reports of these being crushed due to improper lifting of the car. Have you replaced or rotated/balanced tires recently? In addition, there's an air reservoir and of course the air shocks that can leak. If you find an air shock has failed, read the following 

http://forums.vwvortex.com/showthread.php?4574356

Good luck and let us know how it comes out.

Jim X


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## planeadam (Nov 26, 2011)

I've definitely poked through the self study guide (had to do that when the car's computer conked out about 10k miles ago) when I had to find a ride height computer through many phone calls to junkyards. 

We had the local VW dealer scan the diagnostic codes and we tried a new computer, but that didn't fix it. Dealer told us next step was to replace the system (computer, sensors, everything) to the tune of 10k! 

You were spot on with checking the sensor. I was led to believe that a new OEM sensor wouldn't speak to the B part number computer, but this was incorrect. I took the car to an independent garage out front of which I would always see high end Porsches and Mercedeses (Mercedii?) and he downloaded the same code. Dealership told him a new sensor is compatible, so it was ordered. We put the car on the lift and sure enough - the rubber boot on the sensor identified as faulty was off exposing it to the elements. Sensor was replaced, and the system was golden after the car was re-leveled. 

My guess as to the reason for the car sinking slowly (over the course of a month or two) was just natural porosity in the system. I guess I may not have expressed just how much time elapsed between the dealer trips and the garage trip.

Anyhow, takeaways from this for future readers: If you've got a B-type computer (my car is a 2004 US Version), you still can order a new sensor from VW and it will be compatible with the computer.

Next project - adding the rear climate control panel!


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## Jxander (Aug 5, 2008)

Glad the outcome was relatively painless and it's good to know the new level sensors will talk to the older version control module. I am amazed at how reliable these cars actually are. Many problems are similar to yours. Something very simple is wrong, but if it is misdiagnosed the result can be a huge bill such as your $10k dealer estimate. 

Thanks for following up with the solution.

Jim X


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## invisiblewave (Sep 22, 2008)

This is a very interesting story!! Where exactly is said sensor physically located?


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## Jxander (Aug 5, 2008)

invisiblewave said:


> This is a very interesting story!! Where exactly is said sensor physically located?


One at each corner. One end of the level sensor is attached to the suspension and I assume the other end is fixed(attached to frame?). It looks like a rod(arm?) that pushes a lever and the lever is connected to an electrical box that apparently sends a signal that is translated into vehicle height. Believe it or not, I haven't been under my Phaeton in 3.5 years of ownership. So I have not physically seen th ecomponent. I've only had one repair once I was out of CPO warranty and I've had VW do all scheduled maintenance. I think that is going to change though. I miss doing my own maintenance. However, many Phaeton repairs I'll farm out if they're too muh for me.

You probably have SSP 275 part1 and on page 22 and 23 they show the system components. I think using that diagram it would be easy to find them from underneath. Interesting to note that there are lots of other sensors(senders) incorporated in the air suspension system. Others measure wheel acceleration and body acceleration and incorporate these into the shock adjustments. Pretty amazing system to say the least.

Jim X


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## dlouie (Oct 31, 2008)

I must say that this is very typical these days regarding diagnosis by technicians that don't use their heads and use the shotgun method to solve issues. Disappointing.

Damon


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## invisiblewave (Sep 22, 2008)

Thanks Jim. I'm about to do front pads & rotors, so I'll see if I can eyeball the sensors while I'm down there.


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