I have an 2006 A6, C6, Avant Quattro, 112,000 miles. I was working on the engine splash guard under the car last weekend and had the car on and off the lift several times. I tried to use the jack mode but could not tell that it made any difference while on the lift (all 4 wheels in the air).

PROBLEM
It drove fine for 2 days then on the 3rd day the front jacked up and zero travel (rear seemed about normal), the car front shocks will not air down regardless of the mode I choose (Lift, Standard, Automatic, Dynamic). I can get it out of jack mode but within seconds it goes back to jack mode. I tried driving over 40 mph, no difference, I tried different combination of removing from jack mode and putting it into all the different suspension modes but no change.

Lastly, I took the car home and cracked open the hoses on the front shocks, bled it down to 'normal' height but as soon as the car is started the front goes back up, tops out, and the compressor seems to continue to run (I think it stopped when I selected Dynamic on the MMi

RECENT REPAIR HISTORY
the previous owner had the Audi dealer fix the air suspension within the last 6 months, here is what they did:

Diagnose-Fault for no basic setting adaptation, fault sensor out of range
Compressor and valve block unresponsive
Testes and all 4 corners and will hold 25lbs pressure
System will not accept input for vehicle heights
**Suspension control module and compressor valve block are faulty

R&R Suspension level control module and compressor valve block and code and adaptations
**Relay part #4ho 951 253 a (replaced?)

**Replaced the compressor, and replaced sus. control module
Connected b+ maintainer, ran GFF, performed test for sus. module (now reviewing inputs, but A/C (Air Conditioning??) relay failed to activate*****
*Repaired incorrect wire harness previous repair
System now activates and lifts vehicle, 'pop' heard form Left Front corner (blown air spring), needs replaced

R&R Compressor activation relay harness due to incorrect aftermarket harness being installed
5-pin relay currently installed and wired, 5-pin is incorrect this system requireds 4-pin relay harness and connector housing

R&R LF strut (customer supplied (used?)
Repair completed, vehicle sat overnight and did not air down

R&R Left REAR air spring (customer supplied part)

ADDITIONAL INFO
The RF strut has a slow leak, overnight it will air down
Sometimes the Air Conditioning will not engage upon start up but might take 30 seconds or 1/4 mile down the road
One DRL light just went out and one fog light is out (both left side, possibly related, seems everything is these days)


-Any help is appreciated on where I should start looking for solutions or diagnostics
-I do not have the VCAS but it is on my list to get
-Where to start looking for a slow leak on the front right shock (or tubing)
-Per the repair order, could the a/c relay be the air conditioning or is there something in the air suspension that relates to a/c?

The car is new to me and I have a few other issues to sort out (MMI update, get Bluetooth, NAV Update etc...) and will start separate threads so not to get this one too cluttered.

Yes I searched but I could not find this exact issue and resolution
I am very mechanically inclined, but this is my first time with Audi and the complexity of all of the modules/electronics


All help is appreciated and I will try to respond ASAP

 

I meant to write "I do not have a VCDS but will be getting one"

 

One bump for the night crew.