Android Diagnostic Mode - How to Enable it? - Stack Overflow
Special ADB commands are often required as codes are limited.
: An open-source tool for capturing traffic and interacting with the Qualcomm Diag protocol without requiring proprietary software.
Many devices allow you to toggle Diag mode via hidden menus in the dialer keypad. Common codes include: General/Samsung: *#7284# or *#9090# . Xiaomi: *#*#717717#*#* .