Recreating the “Stuck Throttle” Problem on a Toyota

It’s always easy to blame the driver. But perhaps they didn’t actually did deep enough during investigation. This seems like a pretty obscure fault that a manufacturer would not look to troubleshoot too deeply

The investigation found the code was a mess:

“Michael Barr, a well-respected embedded software specialist, spent more than 20 months reviewing Toyota’s source code at one of five cubicles in a hotel-sized room, supervised by security guards, who ensured that entrants brought no paper in or out, and wore no belts or watches. Barr testified about the specifics of Toyota’s source code, based on his 800-page report. Phillip Koopman, a Carnegie Mellon University professor in computer engineering, a safety critical embedded systems specialist, authored a textbook, Better Embedded System Software, and performs private industry embedded software design reviews – including in the automotive industry – testified about Toyota’s engineering safety process. Both used a programmer’s derisive term for what they saw: spaghetti code – badly written and badly structured source code.

“Barr testified:

“There are a large number of functions that are overly complex. By the standard industry metrics some of them are untestable, meaning that it is so complicated a recipe that there is no way to develop a reliable test suite or test methodology to test all the possible things that can happen in it. Some of them are even so complex that they are what is called unmaintainable, which means that if you go in to fix a bug or to make a change, you’re likely to create a new bug in the process. Just because your car has the latest version of the firmware — that is what we call embedded software — doesn’t mean it is safer necessarily than the older one….And that conclusion is that the failsafes are inadequate. […]”

- https://www.safetyresearch.net/toyota-unintended-acceleratio...