Problem:
What BE KEYS do you use to write with Launch X431 IMMO Plus X-PROG3?
I tried VVDI Benz BE Key and couldn’t read key info.
Solution:
Xhorse VVDI BE key green board works. Xhorse BE Key V4.3T with yellow PCB not working.
And also aliexpress cheap one works ( but on those you cannot change frequency).
If cannot read VVDI BE green board, try pull up the key a little bit. Sometimes only pcb put in a hole and pull up 10mm.