2 weeks ago, I purchased my first new MYLR here in Colorado, Hardware 4.
Last night, me, my wife and our dog returned from our first long road trip: 10 days to and from Seattle on interstate highways. Driving out west, we drove diagonally through northwest Colorado, then Utah, Idaho, Oregon, and up into Washington. On the return, we drove straight west through Washington, the north finger of Idaho, most of Montana, then down into and vertically through Wyoming, and straight south back into central Colorado.
In 2 weeks, I have downloaded and installed 4 software updates, the last one was 2 days ago during and after Supercharging. Each update was seamless.
During every day of interstate highway driving (6 days of driving about 450 miles each; I now have 3,200 miles on the car), I experienced unexplained hard braking. Conditions: clear weather, temperatures between 75 and 100 deg F, always straight highway, and no cars or obstacles in the road ahead of me.
My wife became worried about this random hard braking immediately and said "you have to report this to Tesla when we get back home. Someone could hit us from behind!" I told her that I would look into it, and sure enough, I see here on the forum that it is not an uncommon problem.
At first, I had all of the FSD options and all the sensing turned on. After I spoke to a few fellow Tesla owners at the several Supercharging stations we stopped at, I decided to switch off ALL of the sensing and automatic driving options. Here is what I learned from personal experience so far: if I was driving without "cruise control" and/or accelerating, the car did not randomly hard brake. Once I engaged "cruise control", meaning all FSD and sending turned off, but toggled into "constant speed mode" and set the speed with my steering right wheel wheel, it was only a matter of time till repeated hard braking occurred on a random but regular basis, roughly every 100 miles or so (so it seemed).
There were some insects crashing into the windshield on the drive out west. Because this car only has cameras to sense, every few Supercharger stops, I thoroughly cleaned the windshield with plain non-allergenic baby wipes then ran the windshield wipers a few seconds to clear the baby wipe lint. I checked the door pillar cameras and they stayed clean without doing anything.
I drove a similar route with a brand new Chrysler Pacifica Pinnacle PHEV in December 2021, and that vehicle's adaptive cruse control behaved very well. There was snow and rain all along the interstate highways, and I never felt worried about engaging it. When snow built up on the front sensor (located near the front bumper) the dashboard alerted me and I stopped as soon as possible to clean those sensors with a baby wipe or two.
I sincerely hope that Tesla figures out how to stop the model Y from randomly braking hard when something as simple as cruise/speed control is set for use on interstate highways. If they properly address this problem, I might want to purchase a month of FSD when taking long trips: we shall see.
