Buzzer inside HEX-2

[trv2]

I needed to replace the USB plug, so I disassembled the V2 interface and noticed a small speaker inside. But what is it for and how can it be used? I assumed it's to remind not to forget the adapter in the car, but how does it activate, what's the algorithm?

 

[Shaun]

It indicates on certain error conditions of the interface/vehicle, such as alerting for a stuck K-Line. It is more used on the HEX-NET interfaces, where it also indicates for some SD card problems and SD card reset, as well as indicating on button presses for switching wifi mode.