Allroad air suspension left side lift up and down

[roy@pumpa.no]

Hi,
I'm on a frend's Allroad. A 2001 2,7T.
Replaced the right front suspension airbag with a eBay purchased from Germany, because of a LOW car on that side.
Was not able to perform VCDS level adjustment because of head light error.
Thos was finally traced to be a faulty G78 sensor (left front wheel level sensor) and it was replaced today.
Ok, Now I was ready for some adjustments.
The car looked like a sail boat with a wind from the side.
High on left side (450mm), and low on right side (370mm).
Normal VCDS procedure and reported this, but the result was not as expected.
There was no change in the levels.
The left side still high and right side was low.

But another odd thing happens:
The car rises and lowers instantly!
Up and down until the compressor is turned off by the system.
If I go to 34 error codes and reset the turned off compressor, it starts all over again.
Odd measurements in VCDS
https://dl.dropboxusercontent.com/u/...5/IMG_3761.jpg

How the car stand
https://dl.dropboxusercontent.com/u/...5/IMG_3760.jpg


May anyone give me a clue before I send him to a Audi dealer?

[adamss24]

You will need to adapt the suspension as it seems some of the sensors are reading wrong... Also it could be that the valve block is somewhat iffy and might not let air to went out of the bags. You need to do the 402 mod on the susoension, look on ross tech wiki for the right procedure... Report back with results...

[roy@pumpa.no]

Hi,
The 402 mod is what I described above.
High on left side (450mm), and low on right side (370mm).
Normal VCDS procedure and reported this, but the result was not as expected.
There was no change in the levels.
The left side still high and right side was low.
I even tried to tell the car that it's even higher on the "high" side and low on the "low" side but no success.
It keeps running up and down.
A smartguy told me that a non original (china-made) air bag might adapt too much pressure, and blow the safety valve on the oposite side.
I didn't even know that there were a safety valve inside the air bag?
is it any?

[kid-jensen]

Never heard of any safety vsalves in the bags, any more than in tyres....

When I changed one recently for an Ebay (German-sourced, but probably Chinese) bag, the construction and general shape was identical to the OEM one...

Guess that's where the expression "Chinese copy" comes from...

[adamss24]

Try and wind the nuts on the air lines (the ones on the high side) and let some air off, then proceed with the adjustment again. What does the sensors see as height ? Also what is the pressure in the bags ?

[bagpipingandy]

It is not the airbag, did you fit the sensor up the correct way??

is the suspension error light on?

high on one side? does the high side move up and down the same as the other side or no movement at all?

DO NOT calibrate it (402 mod) with any faults as you can get into a bigger mess. for the calibration to work it MUST be able to get to what it thinks is level 2 before the adaption can start.

in your measuring blocks it shows the front height 2 is -52 that is 52mm lower than level 2 is this correct?

values to height comparrison:

-25 is level 1
0 is level 2
+25 is level 3
+50 is level 4

regards

Andy

[roy@pumpa.no]

These readings vary when the car raises and lowers.
I believe this is for each corner?
https://dl.dropboxusercontent.com/u/...5/IMG_3761.jpg

[bagpipingandy]

Do they vary in the correct direction? +ve direction is when the car lifts upwards

-25 is level 1
0 is level 2
+25 is level 3
+50 is level 4

your readings are -50 which suggests it should be unlevel and scraping the ground a corner 2?

what are the fault codes stored?

regards

Andy

[roy@pumpa.no]

The strange thing is that I have no weeor codes any longer, except compressor switching off because of the stress.

[bagpipingandy]

the compressor is designed only to run for 2 mins, if it cannot reach the required level then it haults the system as their must be a problem, its to protect the compressor

we could do with a clear description of the fault, and answers to our questions, to get a clear description so we can help

what I think we have so far:

the car sits not level,

What is the actual error code which stops the compressor?

what does the suspension error light do? nothing, on all the time or flash? or does it come on after you try to change the cars level after 2 mins?

if you press up:

how long does the compressor run for?

does the car actually change level on any corner, or no movement at all?

if you lift the car wheel arch does the measuring block values go in the correct direction for every corner?

from the photo of the car and the measuring blocks It looks like the new bag is not filling but you say the car lifts?? (It keeps running up and down.) does the newly fitted airbag actually lift?


best regards

Andy