I had one drive, where I got a random "check brake system" message displayed for about 20 seconds. It went away on its own, and about an hour further into the drive it returned followed by an immediate cluster power reset. The whole dash went black, and came back in a moment, and the trans commanded 1st gear even though I was doing 85 in 6th previously in S-Sport. Thankfully the transmission did not actually go into 1st, but it sure revved the engine up trying to while I slammed the brakes and went into neutral at the same time. I continued on only for it to happen literally minutes later. I pulled over, shut the car off, restarted it right away, and had no issue the rest of my 2 hour trip.

This happened to me two months ago, on the highway, and scared the **** out of me. I was terrified to drive over 55mph after that the rest of the way home. It's been at least 800 miles since, with no brake warning or cluster power loss. I checked every relay in my fuse box, any connection I could gain access too expecting to see some corrosion or physical issue, but nothing. Has anyone heard of anything like this happening? I'm worried next time I'm highway cruising it's going to drop into 1st gear, and blow my pistons out the side of the block doing 16k rpm!

 

Just wanted to do a followup to anyone who finds this from a web search.

The ETACS unit my car had was under recall. I described the issue to an older service tech familiar with the Evo, and he stated that's something he has heard of before with the ETACS my car had.

They were able to replace it at no charge, despite the mods, and even program it without reflashing the PCM.