The red exclamation mark? That's an odd response. Usually it doesn't care about that code - it happens a lot on some cars when you use tiptronic - never really figured out why, although its probably the F125 on those too. I'd pull it apart and clean up the contacts then spray them with contact grease and bolt it back together. Mine is the original and has been fine since I did that 2 years ago.
I have a couple here that I've been meaning to refurb. I could do one on part ex if you like
The brake switch reduces power since it can't tell if you're braking or not so its not that.
Does that code definitely come back each time? Is it also showing the yellow fault light?