Boom GTS Speedometer
 

Does anyone here know if the Boom GTS speedometer is driven by the BCM/ECM or is it driven by the GPS system as a part of the Nav feature? If it's in the 9 million page manual I can't find it.

I've often wondered the same. If there was a longish tunnel nearby, I'd have the answer.

I am pretty certain that they GTS speed is that of the GPS system, not generated from the bike speedo system.
I know there are videos sharing how to check your speedo and one is to use your GPS indicated speed vs speedo

I had heard the same thing. I have not confirmed it on mine since I have had no gearing or tire changes, but one of my customers at work did a custom wheel, tire, and pulley change and said he now uses the screen for an accurate speedo on a '19 RGS ??

i had heard the opposite. the gts gets it's speed from the vss just like the speedometer. i've not done a direct comparison from a gps to the gts, but i can tell you that if the gts gets it's speed from the gps, then i must have the world's most accurate hd speedometer because the analog gauge and the digital speedo on the gts are dead nuts equal.

The GPS uses the same VSS signal as the Speedo.

easy way to find out, would be to put a jack under the bike , start it up and run it in gear.The speedo will work, then look at the gps. If the gps registers,you know it does not a satellite for speed.

As others have chimed in, and I did some digging, it is the same signal being displayed in the GTS/NAV as your speedo. My original comment of it being from Satellite 🛰 was incorrect.

I've been digging too, and can't find anything definitive. Can you share your sources?

this, no way is it using the GPS