First post here after buying my wife a 2005 A8 about 2 months ago. The yellow and green suspension lights lit up yesterday and the front of the car lowered to the bottom stops. I ran a Vag-Com scan and pulled 3 codes on the front suspension:
Address 34: Level Control Labels: 4E0-910-553.lbl
Part No SW: 4E0 910 553 H HW: 4E0 907 553 F
Component: LUFTFDR.-CDC H06 4480
Shop #: WSC 25166 444 84618
01577 - Turn-Off due to Over-Temp
001 - Upper Limit Exceeded - Intermittent
Fault Status: 00100001
Fault Priority: 4
Fault Frequency: 8
Reset counter: 119
Mileage: 155995 km
Time Indication: 0
01583 - Leak in System Detected
000 - -
Fault Status: 11100000
Fault Priority: 3
Fault Frequency: 2
Reset counter: 79
Mileage: 156017 km
Time Indication: 0
The 10 amp and 40 amp fuses are not blown.
My question is, how do you you go about troubleshooting the air suspension? Is there a way to pressurize the system to look for leaks? Would Vag-Com have given me a different fault code if the struts were leaking? Am I safe to assume that since both struts lowered the same amount that it's not the strut but a leak elsewhere? It seems a lot of folks end up replacing the compressor but there's got to be a way to test for leaks first, right?
I've searched the archives on this board, the Vag-Com website and looked on Elsa for guidance but nothing. I do not have a copy of the Bentley manual yet but obviously see a need for one now.
it can be very easy just with a sprayer bottle and soapy water, first see if the compressor still generates some pressure,
lift the car with a floor jack one side at a time and with the engine running spray around the air spring and look for bubbles.
much easier on the Allroad as the design is different.
you can check the pressure with the vag tool.
Note that lovely WABCO logo on the bottom of the label on those scrap ECAS compressors. Even though the top of the label says Continental, it is made by WABCO (the old acronym for Westinghouse Air Brake COmpany) Rumor has it that Continental will acquire WABCO in the near future.......
First check to see if Compressor is Still Alive and working. Jack up the Front End, Remove Belly Pan, Remove Lower Screws in Front of Driver's Side Wheel. Pull Wheel Well Liner back to Access and Unplug Compressor. Plug a 12V Sourse Directly to the Compressor to see if it Runs/Starts and disconnect if it does. Follow S4master1's instructions if it does Start! Also, if it Starts then your Relay is Blown and needs to be replaced to get rid of the Fault Codes and it's a $20 to $30 Part. If your Compressor doesn't Start then welcome to the Dark Side (New Compressor & Relay)! Good luck and laters,
Mine had exactly the same issues as you've mentioned, including the VAG codes
Compressor dies as a result of not being able to continually pump air through the system.
In my case, the front right strut had failed. The compressor then died, followed quickly by the relay. Took Audi three attempts to find the culprit.
You're question about the whole front dropping meaning a separate issue to struts could be true, but it's likely that the compressor can longer pump up the car and is actually the end result. (Remember that the rear has an air reserve so stays lifted.)
My 2c opinion - strut leak or leak feeding a strut, comp dead, relay fried. I HOPE I'M WRONG THOUGH! Good luck.
I'll plan on jumping the compressor tomorrow to see if it's still alive. I've already got the wheel and liner off so everything is exposed.
Where should I spray the struts specifically? I'm not used to these integrated set-ups. The only other self-leveling suspensions I've worked on were the old BMW E32's that had the seperate resevoirs or bellows.
Your experience is my fear.....or reality. The sequence of fault codes appears to lead me down that path.
Mishar, I found that link yesterday and it's a definite "must" read to understand how the system works as well as component location. I wish it had more diagnostic info but I'm guessing that wasn't the intent of the publication anyway.
At least I know where all the air lines run and can hopefully trace down the leak, if it's not at the compressor, once I verify the compressor works and can pressurize the system.
I pulled the relay yesterday and took it apart and it looks new. Kind of confusing markings on it though. Relay number is 100 951 0001 "Meyhle Germany" and then a paper sticker that says "Made in China".
I did a quick Google search and it resulted in no local U.S. suppliers so I'll probably just cough up the $27 to my dealer for the $5 relay just to be sure if I replace the compressor.