Hello everyone,
It is my first post in this group. I red a lot of info i this group, but i couldnt find exact info.
I have A4 B7 1.8t 8E0909518AQ and i want to read my ecu with mpps v16, but i get an error. With my other auto Seat Leon 1.8t it is working. I bought a cable (add photo) will it read and flash ecu with it in boot mode? If yes it is enough for this ecu to ground 21st pin while loading? At some ecu's i saw people using 1ohm resistors.

do not ground 21 pin. its vcc.

that your cable can be wired who-knows-how. more confident to just put ecu to bench wiring, from external battery / voltage source 12v to 21,3,62 and gnd to 1 and k-line to 43. boot mode flashing needs grounding one of pins of processor inside case.