2015 Switchback B2161 code
 

I have a 2015 Switchback, and the red light on the speedo comes on anytime I press either brake. Taillight works/brake light does not. It throws the B2161 code eeverytime. It isn't the bulb as I have switched it out to see if that was the cause. It used to be intermittent and would go away and the brake light would work fine and no red light on speedo. But now it is any time either brake is pressed. Does anyone know how to fix this issue? I'm not wanting to take it to the dealership if I don't have to especially if it is an easy fix. Appreciate any help.

Anyone know about the code? Tracking that it is a brake light circuit open. Just unsure of the fix

This is the diagnostic chart to check that DTC. Sounds like you've taken care of step one, you can certainly check resistance between the bulb socket ground (side wall of socket) and vehicle ground. Final step requires a breakout box, which would be a dealer check. Since your running light seems to be working, I would assume test 2 is probably passing, or you wouldn't have anything at that socket, so I would check for voltage in the bulb socket at the 2 contacts in the base of the socket with a test light. One will be on all the time as the running light, other should light up with brake pedal/lever engaged (zip tie, or tape front brake lever to make it easier). If you have running power, but no brakes, start looking for damage on that harness, specifically look underneath your rear fender, make sure nothing has hit the harness there. If you have power at those 2 contacts, try to take a clear picture in the light socket and post it.
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Thank you for that info! I'm picking up a HD bulb today to see if that'll work. I read some off brand bulbs won't have the right amperage and the BCM sees it as failing. After that I will see if I have to continue with the steps that you have posted. I appreciate it!

Good news, was the bulb. The bulb I got at HD fixed it.