If the problem is electronic, it will be a “glitch” in either the program or hardware. If it is, all of the diagnostic tests performed are of no use unless the glitch occurs randomly at the exact time that the device is under tests. Otherwise, the problem will never be found and corrected and a total redesign of either the software or hardware will have to occur.
The problem is that the glitch is not repeatable and occurs randomly which means that they can only guess at the cure since they can’t actually reproduce the problem.
I’ve been troubleshooting electronics since 1966 and I can tell you from experience that these types of random errors are the result of poor design and lack of collaboration among the designers.
I would never put my safety and life on the line by trusting any electronic device that I could not immediately override manually. And to that point, with these cars…you can’t.
Interesting thing - the cars reported to still have problems have the ‘smart pedal’ patch now, where hitting the brake and the throttle (i.e., hitting the brake with a stuck throttle) is supposed to tell the computer to cut the engine back to idle. According to the reports, the cars are still ignoring that patch, so somewhere in their code is something that’s gone horribly wrong or there’s something causing EMI/RFI interference that’s confusing the hell out of the computer.