Englishman1234

Hi this is my first time on Audi World with an issue I hope someone can assis me with. I purchased a used A8 in August and have for the most part been delighted by my purchase. Unfortunately around two weeks ago when pulling in to my garage there was a disturbing rattle from the front drivers side followed by both green and yellow suspension lights illuminating. After some research I determined that the ride compressor was shot so purchased a replacement along with a new relay (as was advised in several threads on this site). I installed these yesterday and, drum roll.... nothing! The pump does not run. Does anyone have any suggestion?

Mister Bally

Use VCDS Diagnostics to confirm that the power fuse is blown. Or, just take the Driver's knee air bag & cover off to access the fuse and replace. Quite a bit of stuff to remove properly to access. You don't want to break any trim pieces as they are expensive.

Best to have the proper service manual for this procedure.

Read and follow the sticky at the top of the D3 thread which mentions having both the VCDS interface as well as a service manual. It really is good advice.

Englishman1234

I do not have a VCDS (yet!) but did open the are under the steering wheel to replace the relay. While under there I did pull fuses to check them although I did not know which was which, all looked good. Can you point me to the right fuse and or any other places to look?

Mister Bally

The orange, 40 amp fuse. It is covered with a bracket that has to be unbolted.

But, without VCDS, you could be wasting your time.

Englishman1234

Suspension working, thanks for identifying the fuse!

MP4.2+6.0

1. Tying this off for posterity having been burned myself on what sounds like exactly the same thing: the fuse for the suspension compressor is the 40A one as identified. However from experience, without a microscope you will NOT be able to visually confirm whether it is good or not. The design is not good for an easy visual check like most of these sort of fuses are. Only by testing mine with an ohmmeter did I find it was bad. It had an almost invisible break you could only see in full sunlight--and if you pretty much knew it was bad to look at it that closely.

2. A word of caution: a failed compressor is often a symptom rather than "the issue." That is, they most often fail with a leak in a suspension strut which then has the compressor working way too much. Simple check is to park the car and put suspension in "jack mode" before you shut it down. Then leave it overnight (or longer yet better) and see if it holds level or has dropped at all. Putting it in jack mode keeps compressor from airing it back up if it detects a drop while sitting there. If it drops, find the leak quickly--before it eats another compressor.

Jack88

+1 to both points, make sure you have no loss of height overnight or any lights while driving. If so, you may lose another compressor.

ltooz_a6_a8_q7

Did you turn on jack mode while replacing the pump? Did you get it out of jack mode afterwards?
Don't break more stuff until you troubleshoot correctly.
my suspension failed at 119k miles
Cheers,
Louis