cross-posted from: https://lemmy.world/post/1030687
EDIT: This PDF contains very detailed electrical information for the EEs who wanna go through the complaint: https://www.autoevolution.com/pdf/news_attachements/breaking-nhtsa-petition-shows-tesla-s-sudden-unintended-acceleration-is-real-and-curable-217525.pdf
Last year at /r/RealTesla, a Chinese video of a car rocketing at full speed for 1+ minutes before crashing / killing a pedestrian made the rounds. We all recognized it as one of the weirder cases of “Sudden Unintended Acceleration”, and I think that particular video really changed some minds.
While a lot of SUA events are from driver-error, it began a search into why Teslas seemed to be getting more SUA above-and-beyond the industry normal. This investigation (now filed under NHTSA) suggests that the ADC could be miscalibrated during a load-dump (or other electrical surge-like) scenario.
If the ADC associated with the accelerator pedal is off, then the Tesla will have the pedal at the wrong level of acceleration until the next calibration event, which is not going to happen until over a minute later.
This is extremely similar to that Chinese runaway Tesla, and perfectly seems to explain it. I’m glad that someone seems to have gotten to the bottom of this.
Wow. I’d trusted NHTSA and the researchers who had looked over this previously. Tesla needs to get a software patch out for this calibration process immediately before I stop driving my car.
Given that it’s an issue with the 12v systems I’d be inclined to wonder if newer cars with the lithium-ion low-voltage battery don’t have this issue?
The fundamental problem isn’t the battery per se. The problem (according to the .pdf) is the 300+ Amps the steering wheel is pulling to turn the car left-and-right inside of low-speed / traffic conditions. This is allegedly on the 12V line, but this fundamental issue will still be on the 48V line on newer cars.
Now this problem is widely known, not only in car engineering circles, but also in EE circles. The fundamental problem is that Tesla engineers were ignorant to this problem and built millions of cars replicating this problem. When this issue was first identified in 2019, Tesla engineers (and NHTSA) were too ignorant to figure out the problem despite official complaints coming in.
The issue is that Tesla engineers are incompetent and not deserving of our trust. They could have fixed the problem from the start (as all cars have this brownout problem on the 12V battery). They could have identified the problem in 2019 when the first rumors of the complaints came through. It should not have taken until today, 2023, for these poor users to hire a reverse-engineering expert to pull the firmware off of the Tesla PCBs and figure out what the hell was going on.