94 and 95 A6 AAT K line problems

94 CAR A 100/A6 AAT 1st generation ECU . ECUtools.com supplied obd cable running vagcom 607 works fine no problems check for codes and also timing. (Brothers car )
95 CAR B A6/100 AAT 6 speed 2nd generation ECU. Same cable set up. Recognises the cable but says car not connected.
96 CAR C A6/100 AAT Auto 2nd generation ECU. As car B ( Friends car)
All cars are UK models

I know these cars are particularly strange. Both CAR B + C have a voltage ~9 V at the K post. On CAR B ( my own car ) I tested each line going to the K post and got battery, ~6, and ~9. My theory behind this was that I could isolate the ECU K line. By connecting purely to the K line with all the other line conjoined separately and then all variants of joined etc. The return was always car not connected.
I know the K Line goes through the Immobiliser on a 95on. Can this be the problem area Q1??? Both CAR B + C have no radios and the wiring has been isolated so no issue there. I have trawled the FAQ’s and this forum but can not find any definitive answers.
As to the fact I am using an ECUtools.com supplied unit that’s my choice, and currently I believe it is not responsible wholly if at all considering CAR A.
Any BTDT or help greatly appreciated Ethical tips leave to the side.

Have you tried using Beta 702? Do you get the same behavior?

http://www.ross-tech.com/vag-com/download/beta/current.html

Beta 702 loaded and still no joy even went around the loop again of single connection all variations on multiple connections on the k post. Willing to pay to get this sorted. Car is know running and will be in the south of UK . Any help ????