John Bro

Hello!!! I do have a question. I have a 2020 GMC Sierra. But....when I turn off the ignition and sit in the truck for several minutes, the brake pedal is hard when I try to start it up again - as if the vacuum is lost or something. Additionally, my "Trip" and "MPG" average are both 0.0 instead of actual mileage and MPG like I see at times when entering the cab fresh. Lastly, before finding itself, the warning of "Brake System Failure/ 62 MPH Top Speed" flashed very quickly by. I had my dealer search for a code but nothing there. Thoughts? Why all this after sitting dormant in the cab like on my phone or something? And the Brake Warning doesn't always happen. The 0.0 most always does though after waiting in the cab for too long before start. Thoughts?

I have had all these warnings on my 2020 Sierra. They applied PIT5375C (?) and say it was fixed. Now I get “Brake System Failure 62 MPH Top Speed” at the very beginning of start up. But no brake issues yet. WTF?! 6 visits to dealer thus far. Lemon?

All of this is just truly awful. I have a 2020 Sierra (Elevation) with warning lights and, one day, a totally dead batter. And to think that such major problems can result from some teensy bolt or gasket against something means these "tough" vehicles are now actually very fragile. I do not associate GMC with reliability at all anymore. If I go after them and get a decision in my favor I think Tundra is finally looking good. Sorry, America.

Interesting. I do have OnStar. I have also had the "Service ESC" and "no brakes after 62mph" crap show up. Most recently battery dead and difficult to tow because it seemed to be locked into some kind of stupid safe mode. Do folk recommend we jettison the OnStar on the vehicle?

Okay, I just got my vehicle back BUT - the UBEC bolts were already at 53lb. They could not find what drained the battery. And, given what I am reading here, it is just a matter of time before it happens again. This sucks so hard - got a new vehicle because I have no time for such problems right now at all. Like several of you. But will report back with anything further. I plan to drive by there in a couple weeks and have them check the battery.

Wow, guys - thanks for posting all of this. The battery in my 2020 Sierra is dead with no explanation but with lots of warning lights and guess what - because of YOU, I was able to find this and relay the information to the dealer. Why does it have to be me to come to the rescue? Granted, it is not yet fixed - but it sounds exactly like the issue at hand. Yes, this needs to be recall.