Submitted by WardT on July 19, 2019
I’ve experienced this issue twice with my M3 2019.20.4.2: In TACC it got within 28” of the car ahead and I think it only stopped because I braked. One time I was going downhill (more common to have this issue downhill) but the other time it was on a flat section of the freeway. Both times I was paying attention and couldn’t take getting any closer and braked to prevent from hitting the car in front of me. I purposely got a little closer the second time to see if the car would stop in time, it did not. The car alarmed and said out I was 28” away from the car ahead of me. It may have alarmed because when I hit the brake, the TACC turned off and the Tesla was “barking" at me for being too close. 99% of the time the TACC works great. But for a vehicle almost ready for more autopilot features, TACC should stop 100% of the time. I think the TACC distance was set to 2 car lengths. I plan to experiment with 3 car length setting. What is going on?