AIR SUSPENSION FAULT / SUSPENSION LEVELING CALIBRATION FAIL USING VCDS - 2007 AUDI A6 C6 4F allroad

In my 2007 AUDI A6 C6 4F allroad that has Adaptive Air Suspension (AAS), allowing the vehicle to lower or raise for allroad conditions ;) I was chasing a fault whereby the air suspension selection works fine in COMFORT, AUTOMATIC & DYNAMIC modes (mid-level to lowest height settings) it drops & lifts OK without fault, however when I select ALLROAD or LIFT modes (the highest lift levels) the AAS MMI (Multi Media Interface) symbols (on the centre dashboard) indicated that the system was trying to raise the vehicle (although you could see that the vehicle wasnt lifting) and then the AAS MMI display grey’s out indicating a fault and the yellow suspension warning light flashes.
Cycling the ignition switch resets all fault indications, however the above scenario remains if tried again.
I went through the usual trouble shooting procedures using ROSS-TECH VCDS scanning tools from www.ross-tech.... and performed the SUSPENSION LEVELING CALIBRATION procedure without success, the recuring message found on VCDS was:
Fault message 01437 - "Control Position not Learned" or
Fault message 02646 - "Plausibility of Level Control System".
To avoid damage to the car or equipment when you jack cars with AAS or similar, first you must go into "JACKING MODE" to disable the suspension air control unit..
Subsequently jacking all wheels was uneventful... until I jacked the front R/H side & this was the result!
In hindsight, I think that because the vehicle could not achieve the programmed height levels due to the strut air leak, the height was never "learned" thus the logged fault message.
This is only one of the many faults that can occur on air suspension systems, however my experience may be helpful in trouble shooting your Audi or other vehicles that use similar air suspension systems.
There is plenty of info available on the net/youtube in regards to changing airsprings and air struts, its pretty easy!
Be very careful when working on these systems, consult a professional if in doubt.

[@lachlan7013]

Hi Scott, Truly many thanks for this video as i have just had the exact same problem with my 09 Allroad.
A brief question, the Mechanic has said its best to replace both front air suspension units, as there is (apparently) a huge risk of running one new Air Suspension whilst leaving the other untouched. Should i trust these cheeky mechanics? Did you replace both or just the one?
I very much look forward to hearing from you.
lachie

[@scottroberts9892]

Hi Lachlan thanks for commenting on the video,
I actually only replaced the one faulty unit in my car (that shock was original and 15 years old), my other front shock was actually replaced by an Audi dealer when the vehicle was 6 years old (reason unknown, probably leaking however they only replaced one unit not both), that shock is now about 9 years old. I would guess the life on these units is probably about 10-15 years depending on how you use the system and the roads travelled. Ideally I would have liked to replace both shocks together, however my choice was based on cost, and I'm mainly doing local commuting (in Australia an Arnott aftermarket strut costs ~ AUD$1,500 each + labour if youre paying a mechanic), so I thought I could squeak a few more years out of the other one. The advice your mechanic gave you is normal & responsible information that they should give to a customer, and if I was doing a big road trip a long way from home, I would consider doing the other one beforehand for peace of mind. Coincidentaly I have also replaced both rear suspension bags (Arnott brand) as they were also leaking. Hope this helps your decision.

[@robertbawden1702]

im in ravensthorpe western australia. i own a 2007 audia6c6 and have huge air problems. firstly I've replaced both front bags,relays,, fuses and air distributor but now it won't communicate with bags. it gets halfway thru its mode and turns itself off. its got me stuffed. what can it be? you cannot operate whilst driving. u cannot get it into tow mode. someone please help as it's my only vehicle. I am a mechanic but not an Audi mechanic. I'm 600 kilometers away from the nearest dealer/audi mechanic.

[@AlexandriaHirawani]

valve seals onthe air lines need to be replaced and some tome the line them selves can get splits in them when exposed to heat

[@ar9k]

Hey! Did you find out what the problem was? I have the same problem😅

[@scottroberts9892]

Yes, it was the front air suspension unit.
My suspicion is that there was a perforation/hole in the air bag that was only exposed when the strut extended, like over a speed bump or pothole, which caused the strut to deflate extremely quickly, (as evident when I jacked up the vehicle) causing the compressor to work pretty hard to keep the air reservoir pressure up.
This is also why the vehicle's air suspension height calibration failed continuously (using VCDS), as the height required for calibration could never be reached.
I ended up replacing the front strut with a new Arnott unit from the USA, a truly excellent product.
Good luck with it.

[@ar9k]

@@scottroberts9892 okay! Then i’ll probably replace mine as well, 900$ out the window😆 when i checked for error codes on the pc i only found out that it was the relay for the air suspension but it dosent make sense since it happens on only 1 strut.. well.. thank you so much for answer!

[@ar9k]

@@scottroberts9892 and also did you have to calibrate the suspension after? Or did the suspension level normaly with just 1 new unit?

[@scottroberts9892]

Hi, yes definitely need to do a full suspension calibration when finished, it’s pretty easy to do, just follow the prompts from Vagcom. Just to confirm my original defect was that the front suspension (couldn’t work out which one until I jacked the car) would audibly discharge air when going over a speed-bump or pothole, however the air suspension was operating normally in all modes, unless I selected LIFT or ALLROAD modes, then all selections would grey out and freeze any further selections, until the ignition was cycled off/on. This was presumably due to the massive loss of air pressure in the system and a safety net for the air compressor so that it doesn’t destroy itself trying to keep up with the air demand required for the leakage.
Good luck with your trouble shooting.

[@ar9k]

@@scottroberts9892 okay! Thanks alot! You have been to great help!😊

[@gheorghebivol8310]

Hello 0:09