As you can see in the following quote Emergency Lane Depature system is a system designed to take control of operation of steering from the driver without AP/FSD running.
Emergency Lane Departure Avoidance is activated automatically every time the car turns on and intervenes later (and less often) but more forcefully if the driver allows the car to approach a lane-line too closely or quickly without using a turn signal, or if the car's sensors detect an imminent collision. Drivers can also override this system or turn it off, but it resets as soon as the car restarts.
This is why I think this system is causing the sudden veering in non automated enabled Teslas. But in order for this system to take control it has to believe that the Tesla has departed its proper path. Thats where GPS glitch comes in. The following shows GPS glitches is very common in Electric vehicles.
Irrespective of the type, EMI in electric vehicles impairs the normal functioning of the electronic systems in them. The most common malfunctions are experienced in audio systems, engine control units, GPS navigation systems, antilock braking systems, air-bag controls, car alarms, collision warnings, and avoidance controls. As the strength of the EMI field in electric vehicles increases, the severity of the electromagnetic compatibility issues also increases.
Tesla Model 3 Alarm Keeps Going Off Some of the Model 3’s alarm sensors can be very sensitive at times. Just like any car alarm, it can be triggered by loud environmental noise such as loud cars and thunderstorms..
But its investigators will also be digging into a question involving a more basic technology: Why isn’t Tesla’s forward collision avoidance system better at preventing crashes like Smith’s — at least when the computer is driving?[/ki]