So this is an I've issue with my 2016 1.6tdi- has anyone had similar issue? My local mechanic didn't have the proper equipment to diagnose and fix, so sadly the car had to be transported to the nearest main Audi Dealer.

Happened suddenly without warning. Symptoms were TPMS warning, Headlight assist and brake warnings all showing up. Car shortly became fully disabled and would not start.

My local mechanic provided the following info for the Audi dealership:

“The CAN is in a recessive state ( CAN high & low stuck at 2.5v) No communication with ECU, ABS & SRS modules. All powers and grounds at ECU okay, Power at front distribution okay. Fuses all okay. Suspect gateway module”

Audi dealer response today after their supposed diagnostic process :

"The technician has and is still working on your vehicle, he’s found the trouble:

He has stripped vehicle to access all modules on the powertrain BUS system. stripped wiring loom in the plenum chamber but still unable to find the short on the bus wire. Stripped more of the interior and traced short to the interior mirror wiring shorting on the roof bracket. Require more time to repair the wiring and put back the vehicle together which is an extra 5 hours. (your vehicle is still stripped at the moment)"

Any experts make any sense of this?

Surely the ODIS would have given him a good idea of where to look for a short circuit?

He was 99% sure it was the gateway module which he replaced to see if it would work (or more likely following my original mechanics theory). It didnt work and they have charged for that as the part was a special order.

My bill was £1800. I told them I was unhappy with the way the car was diagnosed, fitting a part on a hunch, and the length of time it took. I have formally complained to the dealer and Audi. Would like some opinions -Thanks in advance.

Code readers may point in the right direction, but they should not be taken literally. Interpretation based on experience is always needed.

How old is the battery? A defective battery can cause unrelated codes and error messages.

The battery is only a year old.