I was out of town for a week, car plugged in whole time, when I started it I had a "Brake Service" message that popped up. It reiterated itself after unplugging from charging for next couple days, but now there's no error message. And at no time did the 'checklist' screen on driver console indicate there was a problem. In fact, it's never indicated there was a problem - which makes me question whether it actually works? Or was the brake message a 'ghost' error? I think I'm at about 38,000 miles, 2017 T8.