Audi A6 C6 won't start

It hasn't started since this morning. The following error conditions are present:

# Tacho unit remains unclear.
# Steering wheel lock remains unlocked.
# Tiptronic cannot be moved out of the parking space.
# Unable to query OBD interface.

To make matters worse, the car is parked in an underground garage where the ceiling height doesn't allow it to be charged.

I suspect that the control unit on the steering column is faulty and completely disables terminal 15.

Try this: activate the high beam and then check and clear the error memory. Maybe you'll get lucky, and it will start up again after that. I've managed to revive two like that before!

Hello,
I think it might have been caused by leaving the headlights on and activating the hazard lights. After that, clear the error codes, and if you're lucky, you might be able to move the vehicle for now. After that, if your assumption is correct, you will need to replace the steering column.
Good luck.

Best regards, Dago.

Not necessarily. If it ever starts working, you'll need to disconnect a cable at the EKV control unit, and then it will function. There's no steering column lock anymore.

The story is completely bizarre...

When I drove the Polo 6N to Frankfurt on Thursday evening, the Polo developed a leak in the coolant hose of the water pump, so we ended up with 2 broken vehicles parked next to each other .

I mentioned the problems I identified earlier, but I forgot to mention that the new battery provides a significantly lower cold-temperature test current. So, we took them apart and connected them to the charger.

On Saturday, I went back so that the ADAC (German Automobile Club) could tow the Polo. Because the roadside assistance vehicle was easily accessible, we started talking to the person working on an Audi. Quickly, we were standing next to the Audi, and surprisingly, the OBD interface had power again, thanks to a freshly charged battery. He was very enthusiastic and immediately cleared the error code from the steering column control unit, after which the Audi started up again. So, I wasn't able to read the error codes from the SG.

After we weren't able to make much progress in the underground garage because there was no power outlet, we drove to my place. That's all there is to the derivation of the whole thing.

My advice to everyone facing the same problem:
1. Don't lose your cool.
2. Forget those YouTube videos.
3. Directly fabricate the steering column bracket. There are only four screws and four connectors . Then, the SG can be easily disassembled from the workbench.

I sent the engine control unit, the ignition switch, and a key to https://www.arpatronik.de today. After the repair, I will provide an update.

Today, the repair order came back again. I reconnected the starter generator (SG) and ignition switch for testing. The ignition switch now moves smoothly and precisely, and everything is working as it should.

Tomorrow, I will reassemble everything and hope that no further problems will arise in this area in the future.