[kylecordes]

It is frustrating that the OBD2 dataflow, which covers far more than emissions-related features, is only required in conjunction with emissions and therefore does not apply to electric vehicles.

A more thoughtful legislature would have required a diagnostic port for all vehicles. Required that it emit codes covering all computerized aspects of the car. Required that all codes be emitted on the standard port, required that all manufacturers publish documentation for the meaning of the codes.

(Of course it's probably not a matter of thoughtfulness, but rather a negotiation between many stakeholders, including lobby groups with substantial budgets.)

[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.