If your gm mdi2 hardware version is too low so can not connect car to test. follow this article to update the hardware.
1.This GM MDI 2 scanner is without software, Supports online programming with GM SPS or SPS2 Subscription
2. it can support GM CHEVROLET BUICK CADILLAC GMC HUMMER PONTIAC SAAB Vauxhall/Opel 16 pin vehicles from 1996 to 2022.
3. MDI2 support using the original gm software from acdelco.com
