Holding down the internal reset button (if accessible) or simply connecting it via USB while the utility is searching.

Many independent shops and hobbyists use legacy versions of GDS2 or Tech2Win that were not designed for post-2020 firmware. A newer firmware may include or security certificates that older software cannot authenticate. Downgrading removes these handshakes.

This post is for educational purposes. Downgrading firmware may void your device warranty and is not endorsed by Drew Technologies or General Motors. You assume all risk.

Enter device bootloader/flash mode

Interrupting a firmware flash or using the wrong firmware file can permanently disable the hardware.