NEED HELP! SUSPENSION ISSUE!!
 

Hello guys,

Bought a project car 05 A8L recently. Cannot figure out the suspension issue. The Front of the car would not raise at all, the rear seems to raise fine. Car function in the MMI is not accessible, pressed the button multiple times, it will not work; although all other function of the MMI function properly.

Been struggling with this for a while, then I decided to remove and check out the suspension control module. Found strange spots on it, not sure wth is it? Is it fried or what's going on with it ? (see pic attached).

Then I decided to buy another one on ebay. Just came in today, the same demn thing on the other one. I'm in the corner now, have just ordered the 3rd one.

Anyone has any thoughts on what's causing the problem and whether the module is burned or is it supposed to look that way?

All help much appreciated!

Thanks!!!

That looks like some protective lacquer applied over certain areas. It is visible on top of those chips too. It can be refurbished module (part number should end with X).

Fixing your suspension should start with VCDS scan. You should definitely have VCDS if you want to complete that project.

In the meantime, does your compressor work? Do you have green and/or yellow light on your dashboard? How do you know that rear end raises when your commands are dimmed?

I dont have VCDS but I have other scanner which is capable of reading all error codes etc... Only 2 codes come up for suspension:

1. 01770 - Compressor temperature sensor, short circuit to positive or open circuit.
2. 01400 - Level Regulation (below lower regulation limit threshold)

Compressor itself seems to work fine, it kicks in and then after the rear end has been completely raised it shuts off. I've disconnected the air lines of the both front struts, air seems to pump fine when the compressor is working, but the struts are not raising.

I do get both green suspension light and orange. My MMI is not dimmed, everything works fine, just the CAR function is not accessible for some odd reason.

I do also get these codes:

00003 - Control Unit, faulty or not basic setting/adaptation
01042 - ECU Fault, no symptom, permanent.

So what do you think it might be ?

THanks for reply!

VCDS scan would be better because most guys here are familiar with it. You said only two codes under suspension and another two under what? Have you tried to delete them? Do they come back right away?

Yeah I understand but for now that's all I have, although I'm considering purchasing VCDS.

The latter two codes were under: Infotainment - Control Module Information front.

I have also purchased one front strut, it will come in a week or so, not sure if it will make any changes but it's worth a try.

What's weird is that the CAR button is not accessible, I can't access the Raise Vehicle Features, wonder if that is the cause of the front not raising.

What do you exactly mean with "not accessible"? It is physical button under your right hand. Is it not working?

The car button itself appears to be fine, it's not broken and seems to be pressing up and down without sticking. But when you press it nothing happens, the "CAR" Screen on the MMI does not appear. So for example, lets say I'm in the "Radio" function of the MMI, then when I press CAR button it stays in radio and does not switch, thus it's basically not accessible.

So maybe that's part of the problem why the front is not raising, not sure....

Do you know which module is responsible for the CAR feature ? might just be a software issue...

level
 

1. 01770 - Compressor temperature sensor, short circuit to positive or open circuit.
2. 01400 - Level Regulation (below lower regulation limit threshold)

Compressor itself seems to work fine, it kicks in and then after the rear end has been completely raised it shuts off. I've disconnected the air lines of the both front struts, air seems to pump fine when the compressor is working, but the struts are not raising.


seems to me you already found the problem and is right in front of you.

Level Regulation (below lower regulation limit threshold)
the car is too low to allow any adjustments thru the mmi system and it shuts down.
jack up the front of the car to same level as the rear and it will start responding.

I've disconnected the air lines of the both front struts, air seems to pump fine when the compressor is working.
so if air is going to them and they not going up, what does that tells you?
what happens when you pump air on a tire that has a puncture?

good luck.

s4master

Thanks for your input. So according to you, the reason why MMI "CAR" function is not accessible is because the front of the vehicle is down and it's not turning on ? Shouldn't it be working at all time though? I will try to jack up the car and see if that helps.

As in regards to front struts leaking air, yes it could be a possibility. But I was not able to hear or see any apparent leaks with soapy water. Is there like a valve on the strut itself that might not be opening up and letting the air in ?

Anyhow I should be getting a new strut next week, we'll see if that fixes anything. But the "CAR" function is still worrying me, wth is it not working, maybe it's the source of this problem.

thanks,

Dan McBoost had the same problem as you, the CAR didn't respond, I think he fixed it by replacing the panel. You can ask him for more information, page him here or page him in the other forum.
How can you fix the suspension if the can't access the suspension controller which's in CAR? Don't panic and start to fix one thing at a time, you may screw things up more. Get the CAR working before doing anything else.

Cheers,

Louis