Reading in speedometer data

I’d like to read in the speedometer data from my 2015 GEM e4s using a microcontroller for an engineering project. Does anyone know what wires provide that data to the dash display and what form the data takes (analog voltage, serial, etc)? I’ve probed around a bit but can’t quite figure it out. Any thoughts are appreciated.

1 Like

Older Gems, using ge controllers receive serial data from pin 23 on controller via Gem electronic control module.
Odometer information is stored in controller.

If you only need speed information, the green wire from motor hall sensor gets pulled to B- (black) four time per revolution.
That is where controller gets data for speed and miles/km.

1 Like