Leondrew

Hi all,

I have a 2004 allroad with 2.7L engine. Its air suspension is not working properly. It can stay in certain level for a long time with no problem, but it will drop to to the lowest level if the speed exceeds around 70 mph, and won't come back to normal level. I trid to manually lock the car at level 2, but that was unlocked immediately even at 10 mph. Since speed is the one that will lead this drop, I am thinking to remove the input speed signal to the air suspension control module (J197?)so that the car will not ajust itself during driving, instead, controlled by me manually. I opened the side trim and found the control module, there are totally 25 wires connected to 25 out of 50 pins from the unit. I am not sure whether the green line (pin 15) is the input speed signal. Any help will be greatly appreciated. Also I have found some websites are selling coil springs to replace air springs, where they will ask customers to bypass four wires using their hardware, does anyone know the working principle? Thanks.

Leondrew

DOALLAR

Good luck!
https://forums.audiworld.com/attachm...0&d=1389187860 <---Suspension wiring diagram.

Leondrew

Thanks! Using my attached figures, can you tell which wire is for the speed input?

Old_School_Audi

The diagram shows A108 as the speed signal. That leads to the ws/bl (white/blue) wire at the #9 pin on connector.

Leondrew

Cut wire # 9, tested on free way, dropped again, won't raise up. Conclusion: wrong wire or method. Thank you all the same

Romario

Keep slowly! Speed signal tranmited by the CAN. If you want to fix suspension in one level - use manual mode or eremove fuse №17.

Leondrew

Thanks. I am wondering how to choose manual mode? Did you mean by pressing the up and down buttons simultaneously for a few seconds? What I need is just a fixed level such as Level 2 or 3. I can raise the car manually to level 3 after restart the engine, and it will remain at that level as long as I don't go to free way or exceed 70 mph.

Also, do you know where I can find fuse No.17? Is there any wire that is directly connected to that fuse from the suspension control unit? I am thinking to replace the air springs to coil springs if I cannot fix it at certain level after these tries. (The local audi dealer asked for more than $3,500 to replace the two front air bags which were leaking and the compressor according to their diagnosis. This is much higher than I had expected, and if the two rear bags begin to leak some day, that may cost another a few thousands.

PetrolBear

Search for SSP243 with Google. Pdf doc, insidie is the wiring diagram.
As far as I know you in MY2004 no manual mode is present. You can choose manual mode by pressing up or down for a few seconds (only one of them! - if you trigger both, the car goes into "jack mode" deactivating the suspension contolling - only for service works).

So read through SSP243. I my point, the control strategy is genial, basically. I would not recommend to modify the system (Anyway it would emit the yellow triangle as well.)
You either have a faulty control module, or rather a wiring problem, or the control module receives a false signal from any or more of the level senders. The latter one is the most probable. Bad or noisy signals can fool the whole system. Don't you have an oil leak on the front? It can make the senders' signal noisy as far as I experienced.

Romario

Could you explain reason of your complaints?
Fuse №17 installed under the left cover of dashboard.

Leondrew

No complaints. I just could not afford that money at this moment thus was seeking for an alternative way which makes sense to me. If the speed signal is the only factor that can bring the car to low levels, then why not just stop it going to the contorl unit? (The manually up and down button only work when not driving) Unfortunately, my idea may be wrong.