If it suddenly does something wrong will simply tapping the brakes or moving the steering wheel turn off the self driving or can it only be turned off by the same way it’s turned on
Ha. It's called an intervention.
First: Let's be clear. This is a 2-ton hunk of technology that, while having four wheels, brakes, a steering wheel, a go pedal, a stop pedal, and All That Jazz, is Not Quite like any vehicle you've been driving before. Unless you're truly stuck for time, I'd strongly suggest reading through the manual. If you're in the car, with the screen active, on the bottom row there's a small icon with three horizontal dots. Hit that, and you'll get a Lot More Icons. One of them looks like a binder and has the fateful words, "Manual" on it. Tap on that and there's 500 pp. of manual to go through. Mind you, it's like any other car manual you've ever looked at, where the first 1/3 (or more) is all about where the controls are, how to use the seatbelts, and that stuff: Actually driving the car is at least 1/3 of the way in. But read it. You'll discover weird things, like the panel that comes off on the bumper so you can "jump open" the frunk, allowing one to recover from a dead 12V battery. (Yeah, the car's got one of those, too.)
Main point is that there are places that have that nifty red or yellow triangle with the exclamation point in it with Dire, and Not-So-Dire warnings. Don't depend upon $RANDOM gonzos on the internet to tell you what's in those things - and I guarantee you, with the Tesla, you get a new set that doesn't match up with what you leaned in Driver's Ed. It's not that they're bad, or weird, or anything: They're just different, and, as car operator, you'd better for sure be aware of them. The manual does get updated as the feature set gets updated and matches the car.
Other place the manual lives is on the Tesla.com account; you can read it there, or download the pdf.
So, say you're chugging along on FSD. You're truly, duly, supposed to have at least one hand on the wheel; you're supposed to be torquing it back and forth a bit, too, otherwise the car won't think you're there and will disable FSD for the current drive. Same with eyeballs: The car uses the interior camera to check whether you're looking (mostly) out the windows; a few second of
not looking out the windows (cell phone, screen, the guy in the back seat, etc.) and you'll likewise end up with a disabled FSD. They
really want you supervising the car, not reading War and Peace or watching a video. And doing those things (assuming the car wasn't nagging the heck out of you) is a good way to end up dead, or in an accident. It really
is a Beta.
So, you've got FSD running and are navigating to your favorite destination. Here comes a left turn. On 98% of the turns, the car will slow, wait for traffic to clear, and make a nice, smooth turn. The other 2% the wheel will jerk, you get the idea that the mechanical Student Driver has lost it and is going to ram something. In which case - turn the steering wheel where you want the car to go, you'll feel some resistance, and the car will let go abruptly; you are now in charge. Or hit the brake, and, again, you're in charge. You can gas it while in FSD (to speed up a little, say) and the car will stay in FSD, but it will also pop up a warning not, "FSD will not auto brake while you're gassing it" or something.
There are a
bunch of options around FSD. Honestly, you need to read the manual, then go through all those screens and settings and make sure they're set the way
you like.
Having said all that: Just came back yesterday from a trip up to Boston and back to New Jersey. 90%+ of the trip, both directions, on FSD. It works really well on interstates; will switch lanes back and forth; change speed with speed limit signs (and what's in the mapping software), and it's actually a bit easier doing it that way. The car will absolutely not change lanes into somebody in the blind spot (all those cameras) and tracks the middle of a lane pretty blasted well.
It also acts a bit like an advanced student driver. When it's not absolutely crazy out, it does a good job. In a heavy rainstorm, not as much.
This is going to sound a bit silly, but if Tesla pinkie-swears you'll keep FSD on a factory reset, I'd strongly suggest that you do that thing. Before you can use
any of the car's advanced features, you have to click through a variety of warnings and instructions, on anything from data collection (Tesla's actually pretty good about that, nothing gets sold) to things like FSD. Reading all those things is Good For Your Soul, and Fair Warning, besides.