HereInOhio

l

ltooz_a6_a8_q7

you already kill the ECU, that's why all your electronic components no longer working. Expensive mistake if you'd done that.

Cheers and good luck,

Louis

ltooz_a6_a8_q7

Engine control unit, you're correct. You should use VCDS to communicate and get the true failures of the electronics stuff.

You can get one for about $30 or $350 (full version). that will tell you pretty much everything. When you get the codes, you will see clearly what components fail.

Check the board to see if there's anyone near your area. I think there are a few in the A8 D3 forum.

Cheers,

Louis

ltooz_a6_a8_q7

you can go to individual module and check to see what fails. Right now your concerns should be what's NOT working and it seems comfort control module is what you need to communicate with.
First thing to do is to clear all codes, go to every single module and clear them with your cheap VCDS. After everything is cleared, then restart the engine, drive around and get the codes again. When the battery is dead and jumped, all codes were recorded and many problems caused by dead battery.

Cheers,

Louis

ltooz_a6_a8_q7

Clear codes only clear the fault, if the fault is intermittent or fixed, it won't come back.
I think you should clear all codes if you have the full version, I don't know if the cheap version can really do that.
1. Find out what's not working in the car, check for codes on that module only.
2. You can check the components by visual inspection + remove and install to make sure connections are good.

Cheers,

Louis