GM MDI Multiple Diagnostic Interface NO connection problem can be solved by reflashing MDI diagnostic scanner.

Reflash GM MDI:
step 1 press button and connect with power

2 wait about 10 secs ,keep press the button,no stop

3 when all light turn on,you can take off the button

4 connect with usb key ,prepare for reflash

5 open GM MDI manager ,choose recover

Reflash GM MDI:
step 1 press button and connect with power
2 wait about 10 secs ,keep press the button,no stop
3 when all light turn on,you can take off the button
4 connect with usb key ,prepare for reflash
5 open GM MDI manager ,choose recover