Allroad drivers air suspension info please

[canadianA4B7]

Car had some problems a while back so i took it off the road. Got somenice weather today and trying to figure out the proble. Installed an electronic battery kill switch today. Now onto the questions
1.Get into car start raise to level 4. Turn car off lock doors disengage battery car seems to hold level 4 w no problems.
2. As soon as the car battery is turned back on the back end drops. You hear what i believe is the solenoid open and air being released. Which seems to happen 2 or 3 times dropping it down usually to level 2. I have not let it sit overnight yet but would assume it would drop to the ground.

So now if power is off holds air i assume bags are fine? I have 2 replacement rears if anyone would suggest replacing them
I have 2 replacement sensor that i need to pick up, i assume they are faultytelling the car to drop when power is back ON in the car? I would assume replacing them 1st would be the problem.
Or has my solenoids crapped out and they are just opening as they feel? If so i assume ill be looking for the control unit?

Vag com was just cleared. No codes after cycling the car on and off a few times.

Suggestions are welcome. Please advise. Ive searched and not found anyone doing a trial and error by removing battery. (4:00pm)

(6:40 pm)Its been about 2.5 hours with battery off and still holding on level 2 right now.

[canadianA4B7]

I left the car on level 4 over night and it remains at level 4. This was done with battery not powering the car.

Today im going to test what the car does with the battery powering the car. It seems that as soon as the battery is powering the car and key is off the car drops.

[nemick]

I left the car on level 4 over night and it remains at level 4. This was done with battery not powering the car.

Today im going to test what the car does with the battery powering the car. It seems that as soon as the battery is powering the car and key is off the car drops.

The fact that it stays up when the battery is disconnected pretty much rules out leakage from the bags. Are you able to tell if the compressor is running a lot when the car drops to level 2?

Neil M.

[canadianA4B7]

the compressor runs no problem. it does seem like its working a bit harder then it has in the past. could it be that its needing a rebuild? set the car on level 2 last nite and this morning when I got up the right rear was sitting on the bump stop. so it seems that the right rear bag is a culprit. and it could also be that the compressor is tired and doesn't want to maintain the proper height.... perhaps the rear sensor is crap aswell and therefore not requesting more air, not turning on the compressor, not doing what its supposed to.

resolution for now will be to install the spare rear bag ive recently bought. the sensor when I can pick it up from my mail box. and perhaps buy the compressor rebuild kit for $40 or so and try that. so id be into the repair for less then $200 and hopefully be able to get a few more Kms outta the air ride. if the air ride goes south again I think coilovers would be a better resolution then dumping more cash into an aging car.

[8520]

Suggestions are welcome. Please advise. Ive searched and not found anyone doing a trial and error by removing battery. (4:00pm)

.

Yah. Get rid of air suspension. I've actually made a slight profit switching to a6 suspension.

[canadianA4B7]

Yah. Get rid of air suspension. I've actually made a slight profit switching to a6 suspension.

Slight profit is what I could use right now!

[nemick]

the compressor runs no problem. it does seem like its working a bit harder then it has in the past. could it be that its needing a rebuild? set the car on level 2 last nite and this morning when I got up the right rear was sitting on the bump stop. so it seems that the right rear bag is a culprit. and it could also be that the compressor is tired and doesn't want to maintain the proper height.... perhaps the rear sensor is crap aswell and therefore not requesting more air, not turning on the compressor, not doing what its supposed to.

resolution for now will be to install the spare rear bag ive recently bought. the sensor when I can pick it up from my mail box. and perhaps buy the compressor rebuild kit for $40 or so and try that. so id be into the repair for less then $200 and hopefully be able to get a few more Kms outta the air ride. if the air ride goes south again I think coilovers would be a better resolution then dumping more cash into an aging car.

Do you have VAG-COM? I suspect that changing the sensor will be a futile move. If it weren't working, the right rear wouldn't be lifting correctly in the first place. It is possible that the rear air bag has a leak, but only in level 2. If you do have VAG-COM, there are various parameters that we can check for function. If you do purchase a rebuild kit for your compressor, make sure to get the one from bagpipingandy. The flea bay variants aren't very good.

[Racin2redline]

It seems like it could be a bad check valve? you can view their position on vag com .. Can't remember the block.. But there's only so many. How long after you park it does it lay down?

[canadianA4B7]

Do you have VAG-COM? I suspect that changing the sensor will be a futile move. If it weren't working, the right rear wouldn't be lifting correctly in the first place. It is possible that the rear air bag has a leak, but only in level 2. If you do have VAG-COM, there are various parameters that we can check for function. If you do purchase a rebuild kit for your compressor, make sure to get the one from bagpipingandy. The flea bay variants aren't very good.

Awesome info I have been looking into bagpipeandy for the kit he sells. That would be the route I'm going to go for compressor rebuild. Anyone know if he is on here at all or just use his website?

[canadianA4B7]

It seems like it could be a bad check valve? you can view their position on vag com .. Can't remember the block.. But there's only so many. How long after you park it does it lay down?

I'm going to do some scanning w vag com tonite. I'll need to search to find out which block I'll need to scan. But this sounds promising. The car doesn't take long to drop back down. Have not actually timed it but while standing outside the car on level 2 after a few min I did hear the solenoid open I believe. I thought it was just leveling itself as its parked on a slanted driveway. Perhaps this check valve is opening and dropping the right rear.
Is it one check valve per air bag? I am sure the bag leaks after the numerous tests I have done. Now a few months back i hit a larger pot hole which destroyed 2 rotiform wheels I assume this may have popped a hole into the rear bag.

[G0to60]

Before you go too deep into the valve block and sensors I would do a leak check on that rear bag. Take off that wheel and jack up the corner to a simulated Level 2 and spray with soapy water.

bagpipingandy is on this group and he pops in on occasion. I've used his rebuild kit and it works well.

[ForceBwU19]

My allroad is doing the exact same thing, drops on the right rear corner when parked. I haven't tried disconnecting the battery. I did try parking it in "lift mode", no change. It started when the weather turned bitter cold and has been persistent ever since. I replaced the right rear bag + strut assembly with a known good assembly and it made no change, did it the next morning as if nothing was changed. I did a thorough leak check with soapy water and found no leaks. While doing the leak check I also heard the same "psst" sound from the area around the valve block. Almost as if it was purging air. My gut tells me it's the control unit. My next step was going to be either disconnect the CU overnight and see if it still does it or to back probe the wiring to the valve block and see if it's getting a signal to purge the RR strut.

[nemick]

I'm going to do some scanning w vag com tonite. I'll need to search to find out which block I'll need to scan. But this sounds promising. The car doesn't take long to drop back down. Have not actually timed it but while standing outside the car on level 2 after a few min I did hear the solenoid open I believe. I thought it was just leveling itself as its parked on a slanted driveway. Perhaps this check valve is opening and dropping the right rear.
Is it one check valve per air bag? I am sure the bag leaks after the numerous tests I have done. Now a few months back i hit a larger pot hole which destroyed 2 rotiform wheels I assume this may have popped a hole into the rear bag.

Block 34. Look at the displayed ride heights. They're in millimeters. If the front pair look pretty close to each other and the rear pair look pretty close to each other, jack up each corner one at a time and make sure the number being sent by the sensors make sense. In controller 34 there is a bunch of information that you can use to narrow down the problem. One of the main things to notice is how much pressure is actually being made at the accumulator. It needs to be at least at 3.58 Bar. It won't make much more than that unless you're actually driving. Anything below that suggests poor compressor efficiency. You may have to get the compressor running several times to max out the pressure in the accumulator. When the right rear is low, turn on the ignition, but don't start the engine. Give it several seconds and see if the compressor starts running to pump up that corner. Go listen at that corner and also do as someone else suggested and spray with soapy water to detect any leak. Let us know how you progress.

Neil M.

[nemick]

My allroad is doing the exact same thing, drops on the right rear corner when parked. I haven't tried disconnecting the battery. I did try parking it in "lift mode", no change. It started when the weather turned bitter cold and has been persistent ever since. I replaced the right rear bag + strut assembly with a known good assembly and it made no change, did it the next morning as if nothing was changed. I did a thorough leak check with soapy water and found no leaks. While doing the leak check I also heard the same "psst" sound from the area around the valve block. Almost as if it was purging air. My gut tells me it's the control unit. My next step was going to be either disconnect the CU overnight and see if it still does it or to back probe the wiring to the valve block and see if it's getting a signal to purge the RR strut.

I would suggest that the next time you're hearing air coming out that you also spray the valve block. If you can hear air escaping, it's either trying to equalize the rear end or it's leaking somewhere. In my experience, the sound of it equalizing is quite different than a leak.

Neil M.

[ForceBwU19]

I would suggest that the next time you're hearing air coming out that you also spray the valve block. If you can hear air escaping, it's either trying to equalize the rear end or it's leaking somewhere. In my experience, the sound of it equalizing is quite different than a leak.

Neil M.

Where is the air pressure released? It must have a filter of some sort? Do you think we're hearing the air moving through the valve block rather than being released to atmosphere?

[canadianA4B7]

Nemick, thanx forthe info. I havent had much timethis week. I though yesterday w/ the small weather break i would have time, but as usual life got in the way and i didnt get home till well after dark. Its exam week for me so studies have been takinga good amount of time. This weekend looks promising. Ill keep things posted as this progresses. If i can ill also change the RR suspension and go from there. The valve block about center of the trunk access from below the car?

[nemick]

Nemick, thanx forthe info. I havent had much timethis week. I though yesterday w/ the small weather break i would have time, but as usual life got in the way and i didnt get home till well after dark. Its exam week for me so studies have been takinga good amount of time. This weekend looks promising. Ill keep things posted as this progresses. If i can ill also change the RR suspension and go from there. The valve block about center of the trunk access from below the car?

The valve block is to the right of the compressor, immediately in front of the spare wheel well. The block can be seen without removing the sound/debris panel and is identified by all the multi coloured air lines going into it..

Neil M.

[G0to60]

Here's a picture of the air lines and their colors. You can see in the drawing the edge of the compressor and that's how it's set up under the car.

[ForceBwU19]

Here's a picture of the air lines and their colors. You can see in the drawing the edge of the compressor and that's how it's set up under the car.

Do you know which of the N148-151 valves controls the RR strut? I have a wiring diagram that tells what wire controls what valve but I dont know which valve controls the RR. I'm thinking I'm going to back-probe the wiring to my valve block and see if its getting a signal to open the RR when the air noise is heard and go from there. If its getting a signal (key off engine off) then its gotta be a CU cause it shouldn't really regulate the height after the key is turned off right?

Sorry not trying to jack the thread - I'm thinking we may have the same cause of our issue being that both cars have the same symptom and we're hearing the same noise.

[G0to60]

I'm getting these diagrams from this technical package online. It goes over all of the allroad air suspension components, modes, wiring, pneumatics, etc. It's based on the early 2000 and 2001 cars that had the manual mode but most everything else is the same.

http://www.volkspage.net/technik/ssp/ssp/SSP_243.pdf

Here is the Pneumatic diagram:

[ForceBwU19]

NICE!!

[canadianA4B7]

NICE!!

I have no problem with you investigating OUR problem!!! I c no harm in your interest in sorting out the issue we are both experiencing.

the images provided are excellent help. today we got a massive downfall of white bullshit!!! about 4 billion pounds of it I believe!! as soon as I can get some of the snow scraped off of the allroad and I can have a few hours of spare time to do some digging I think me and ForceBwU19 are likely seeing the exact same problem. id like to swap out the RR bag though and see if that actually is my only issue. but it seems it could be bigger problem

[bagpipingandy]

Awesome info I have been looking into bagpipeandy for the kit he sells. That would be the route I'm going to go for compressor rebuild. Anyone know if he is on here at all or just use his website?

Here I am :)

what fault codes show up?

regards

Andy

[ENDEE666]

When I first got my Allroad I spent a while troubleshooting a leak in the left rear. It held level 3 & 4 fine. But 1 & 2 would drop if it sat. The leak was at a certain point in the bag that only leaked when it was folded to reside at level 1 or 2. I swapped out that bag & strut with a used one and I was fine.

When I put the Arnott Gen 2's & Bilsteins in, I had tons of bad luck. One line sprung a hole. One bag leaked at the top, where the front top of the bag assembly meets the top hat that mounts the upper control arms. Those are other places to look if it is not the bag. Lines, fittings, the distribution block (manifold) and the O rings at top & bottom of each bag.

Do the soapy water test. Shake up some dish soap & water in a spray bottle and fire away. To do testing with weight on it, I took the wheel off at the selected corner and supported the rotor hat with a well-balanced jack stand. That way the wheel was not in the way. Use another under the car for safety, but not touching where it supports the car. You want to make sure the weight makes it leak where the issue is. Once supported, turn on the car and take it out of 'jack mode' and listen/look for bubbles forming. I would not recommend trying to adjust different heights while only on a jack stand. If it leaks at level 2, do it there.

[canadianA4B7]

Spent the last few hours tearing out that right rear shock. Did the soapy water test, which seemed that was leaking a tiny bit through the bottom of the bag. Swapped in the extra (just the right for now) and bolted everything back together. Took for a test drive did not drop.

I did hear the compressor kick in a few times while on the road (rather the relay under the dash, i have an ear for that sort of stuff being an electrician) wasnt too sure if it was correcting itself for level or for a small leak. The compressor is much quieter with the bag replaced? Is that odd? And the bags seems to be "quicker" to fill up at a stop. Now im sure a compressor rebuild would be beneficial just cause. I will run vag com later as my in car reader only showed a P0130 which i believe is due to me not running cats. Ill checkit in a few hours to see if it is staying up on level 2 which is where it was dropping from b4.

Oh and i should do the other shock assembly, the ass end felt much less boat like a bit stiffer with the replacement bag and shock.
Everyone keep fingers crossed!

[Racin2redline]

I'm crossing my fingers for you man! Air suspension problems suck. I guess that small leak was enough to make the car drop.. Maybe it was dropping the other side too to keep it level?

[canadianA4B7]

The only spot that was droppin was that bag. I left it sitting on level 2 last week. When i went out the right rear was on bump stop the rest of car remained. When i put the key in the level light came on but it would pump it back up to level 2 without issue. So right now is the big test in my opinion. If it stays up possibly problem solved. Possibly, remove all the air ride and buy A6 front parts and a set of coilovers. Then say F U air suspension!

still holding on level 2 after approx. 5 hours!!!!!

[canadianA4B7]

So car holds air just fine. But why in hell is the steering wheel out of alignment? Wtf happened?

[ForceBwU19]

Did you take the toe or camber eccentric on the rear subframe loose? That would affect your alignmentand ssteering wheel center

[canadianA4B7]

I only released the rear lower control arm? I tried my best to get it back to the exact same way it was removed. An alignment shop shud be able to re align everything?

Could it be the right rear speed sensor? I had could not get it out so i removed all the plastic clips from the control arm and moved the wire in order to get the shock up and in. Could i have damaged it? It seems as if that tire is not keeping up when accelerating. Ill check to see if anyone has one that i can buy. See if that is the issue, and ill get an alignment.

[canadianA4B7]

codes as requested the bag holds air eems to be out of alignment, seems one wheel isn't up to speed with the others braking felt a little shaky. now ive ordered a replacement rear wheel speed sensor as i assume i damaged it trying to remove it. it was really hard to remove i soaked it with wd-40 and took my time but it was rusted very badly. but i did get all the rust off and was able to turn it but not able to pull it out at all. perhaps it is the brake pedal switch which is causing the 2 faults.


now for codes the computer is reading

Address 03: ABS Brakes Labels: 8D0-907-389.lbl
Part No: 4Z7 907 389
Component: ABS/ESP allrad D57
Coding: 06395
Shop #: WSC 02325
VCID: 09194E153327EA56CC9-5140

1 Fault Found:
01435 - Brake Pressure Sensor 1 (G201)
35-00 - -

Address 34: Level Control Labels: 4Z7-907-553.lbl
Part No: 4Z7 907 553 B
Component: - 2C1A1 X031
Coding: 25500
Shop #: WSC 09999
VCID: 44879F215485773EFFF-5140

1 Fault Found:
01316 - ABS Control Module
79-00 - Please Check Fault Codes