How to solve GM MDI Interface not connecting errors?

Here are all solutions aimed to help fix GM MDI multiple diagnostic interface connection/communication issues (connection by usb, wireless ethernet, wired ethernet)… big thanks to all contributors and obdii365.com

For mdi not connecting…

First, you should make sure that the MDI Manager software should be installed on the PC and the MDI must be powered up before you use it to communicate.
Also the MDI should be configured for wired ethernet or wireless communication. If the USB is available, the MDI will connect by using the USB and if not, the MDI will connect by using wired ethernet and if neither of them is available, the MDI will connect by using wireless.
If the MDI can not communicate with the MDI, you should check the cables if they are securely attached to the MDI, if the MDI has completed its power up sequence, if the connector pins are clean and if the MDI Manager software is running.

In detail…. mdi connection can be discussed in the following 4 parts:

Part 1: GM MDI USB connection
Part 2: GM MDI connection by wireless ethernet
Part 3: GM MDI connection by wired ethernet
Part 4: Tech support: GM MDI not connecting

Part 1: GM MDI USB connection

And if you connect them by USB, you need to check the MDI USB connection is detected by windows. About the solutions, you can connect the MDI to the PC USB port and power up the MDI. Open the Network and Dial-up Connections Window from the Windows Control Panel. Then check for the device name ETAS USB Remote NDIS Network Device. If it is not running, check all USB ports on the PC and verify that the MDI is powered on.

GM MDI Manual: What if MDI fails to connect on USB
interface?
Check USB cable connections.
Check Firewall Settings on your PC.
Verify a USB Hub is not being used (MDI has a fixed USB address).
Verify that only one MDI is connected to your PC using USB.
Verify the USB driver has been installed on the PC (look for device name ‘ETAS USB Remote
NDIS Network Device’ under Network Connections).
Try connecting to other USB ports on the PC.

Part 2: GM MDI connection by wireless ethernet

If you connect them by wireless ethernet, you should make sure that wireless communication is enabled and the IP configuration is properly set using the MDI Manager software. Then what you need to check is that the USB cable is not plugged in, the MDI is not being used via wired ethernet and the wireless card is properly seated in the MDI. You can contact your IT department and check that your PC is detecting the wireless access point and the correct security settings have been configured for the MDI.

GM MDI Manual: What if MDI fails to connect on Wireless
interface?
Check the wireless card is properly seated in the WiFi GM MDI.
Confirm LEDs on the wireless card are lighted when the MDI is powered.
Verify the MDI and PC are within range of the Access Point or Router.
Verify that the PC is connected to the Access Point or Router.
Verify signal strength of the wireless network from the PC.
Check Firewall Settings on your PC