Garmin Edge/Varia/Mastermind TCD Connection Issue


New Member
TLDR: Varia radar detection will make Turbo Vado 4 restart itself when the bike is connected to a bike computer. This will eventually lead to all the bike remote buttons only restarting and resetting the bike instead of their default function. Bike works fine with Varia when not connected to a bike computer.

So I recently got a Garmin Edge 840 and the Varia RTL515 for my 2022 Turbo Vado 4.0 (among other bikes). How they're connected together is as follows:

DeviceConnected toProtocolNotes
VariaEdge 840, Vado TCDANT+
VariaiPhoneBLEDidn't initially connect these two, but the bike not working with the Varia forced me to.
Vado TCDEdge 840ANT+Power, Speed, and Cadence Sensor
Vado TCDiPhoneBluetoothMission Control
Edge 840iPhoneBLEConnect IQ

The issue I'm having is with all these connected to each other, after the Vado detects something via the radar, it will turn itself off and then on shortly after. It's unfortunate as the TCD screen is much brighter than the Edge screen and I'd prefer to glance at the TCD for radar info rather than the bike computer (I'm aware the Varia and other ANT+ devices can connect to multiple bike computers at the same time no issues). After a couple of restarts, the bike resets to factory settings on its own, so the Vado will lose any and all connections.

After restarting itself a couple of times because of radar detection, I will be unable to push any buttons on the bike as doing so restarts the bike (this video shows this happening). Even the power button does the same thing. The next day after having these issues and still unable to use the bike remote, I made my way to my LBS where I got the bike from to get it looked at. Somehow along the way, the TCD issue resolved itself (EDIT: I rode the bike to the LBS as I can turn it on and its default assist is Sport). I am now able to use the bike like normal. I didn't notice this on my way and only found out when I was about to show the LBS owner about the buttons restarting the bike. I had the radar with me (but not the Garmin Edge) so we paired it to the TCD and I said I'll test it outside to see if radar detection makes the bike restart itself. It didn't so I came back and said I'll keep testing to see if the issue comes up again. They suggested to reach out to Specialized if it does, as there's not much they can do other than maybe re-flashing the bike's firmware. I will reach out to Specialized, but wanted to share in this forum anyway to see if anyone has had the same issue.

I took the bike back home and the radar worked flawlessly with the bike for the 7-mile trip. When I got home, I turned on the Garmin Edge, paired the ebike sensors + the Varia to it (via ANT+) and after the first detection, bike is back to restarting itself again. I am now back to not being able to use the bike buttons as it only restarts the bike. I was going to test other connection combinations but the bike being bricked like this currently doesn't allow me to.

I guess my question is, is there a certain way I should be connecting these things together? And maybe what best practices to observe with this kind of setup?

Bike has less than 900 miles, bought new back in February.
Edge and Varia also bought new just a couple of days ago. I have tried resetting these devices and re-pairing them again to no avail.
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I think the firmware in the TCD is crashing and restarting. You're hitting a bug in the firmware. Your detailed description of the problem is excellent though, maybe Specialized will fix it. I'm a fairly new owner myself so I have no idea how often they improve these things.