[neuralRiot]

There’s something like that (j2534). It was originally intended for reprogramming of emmission-related ECUs but since the hardware and software APIs where widely available many started using the standard for complete vehicle diagnostic. Today you can diagnostic and program almost all vehicle brands (for a fee) with just one VCI and without specialized computers since most run in-browser.

[monocasa]

Pretty much every car model is different though once you get out of emissions land.

Some are even different across an individual model year. Some manufacturers have a bad habit of implementing these commands under the hood as poke and peek memory inside the microcontrollers so you almost need a set of linker maps to make sense of everything.