oneflygli

Hey everyone! Wondering if you guys would have any input on the issue I am having. I have a 2011 Audi A3 2.0T Quattro and it one day decides it doesn't want to start. It cranks and runs for a few seconds and then dies like a immobilizer issue. I went to scan with VAG-COM and i can not communicate with any module what so ever. I checked every fuse and relays and there all ok. I get the green light on the vagcom dongle and under test it says K-line ok. I also have no dash lights, doesn't light up at all, power windows do not work and climate control comes on when the key is on but does not light up on the screen. I have had the cluster sent out and tested and it was fine, I also took the ecm out and was able to communicate with that on the bench. Checked the voltage on battery and even tried with a charger. Cranks just fine and all the lights are bright as well. Only things i have not tried is actually pulling the radio and climate control out to see if i can scan then. I did also get a used BCM (comfort control module under dash) I plugged that in and still couldn't communicate with anything. Once i had that in i obviously lost door locks ect.. but i couldn't code it because i cant communicate with anything. So i have the original one back in now and kinda at a lost. Just wondering if any of you guys have came across this issue or have any input. Some times a fresh mind helps haha. Thanks in advance!