06 jetta brm suddenly dies while driving

i would really appreciate any hint to solve the problem, its driving me crazy.

it feels like somebody turns the ignition of, (its not a fuel problem)
vagcom can't establish communication with ECU, when it dies
almost seems the ECU gets no power
no engine codes, no faulty sensors
temperature gauge goes to zero and the rad fan comes on.
all control lights are on, except glow plug, I guess that rules relay 460 out.

after a few minutes i can start the car normal and drive it normal until it dies again, after 20km or 2km you never know

I looked at several wire connections and ECU plugs for corrosion, cleaned what i could find, no change.

as I said, I would really appreciate hints to solve the problem,

Thx Thomas

Have you checked the car's voltage when the engine is running, and again when it dies and you cannot connect with VCDS?

I know the main engine wiring harness is a fairly common failure item on the 06 BRM cars...but that's only from reading on here. I don't know what the symptoms are when they do fail...or start to fail.

found it, it was a corroded 30amp fuse in that fuse box in the engine compartment , sitting right beside the 458 relay.
if you pull it the rad fan comes on and there is a crank but no start condition.
also no communication with ECU