2016 SR5 4x4: Brake Controller Error + Engine Won’t Start

Throwing this out there to see if any of you Toyota experts lurking about on this subreddit can point me in the right direction…as I am just a plumber and by no means a mechanic!

I’ll start with the obvious one. Could this just be attributed to a mostly dead battery? Dead enough the engine won’t start, but just enough juice to light up the gauge cluster and throw codes?

If not, I can provide a lot more information as to why I’m posing a seemingly simple question to this subreddit. But for now, let’s just say it’s been an eventful couple of weeks concerning this truck of mine that I hardly drive and I’m hoping this “engine won’t start” issue is completely unrelated to the other exciting vehicular developments that have been dropped in my lap as of late.

All input is appreciated!