Can I use C++ to re-program a common passenger vehicle?

[SwissProgrammer]

Can I use C++ to re-program a common passenger vehicle?

I was reading a profile here on bytes.com and found Expertise in C++ and Vehicle Software. That reminded me of a question that I had.

If I wanted to adjust the software in a common vehicle, like a 2019 Ford F-150, or almost any other common passenger vehicle used in the USA, then what language should I use? C++ maybe? And how to go about that?

[Banfa]

The real question is not can I use C++, or indeed any other programming language, but rather what is the platform hardware and how is the software loaded onto the platform.

The truth is when most people talk about reprogramming vehicles they normally mean tweaking the parameters used by the engine management system in its decision making, for example altering the timing on the sparks, which is normally, and often easily, done by connecting the the CANBus which provides access to that sort of thing as well as status data. Note I would not suggest tinkering unless you really know what you are doing as you will certainly invalidate any manufactures warranty and you can easily cause serious damage to the engine.

Anyway back to the original point, if you can work out how to access the platform used by the engine management system and how to create software to run on that platform you still have the issue that your software would need to do everything the original software did plus whatever modifications you plan when you write it. This means you need to know not just about the processing platform but every other piece of hardware it interacts with in detail so that you can produce the correct behaviour, information that would be hard to come by. And of course that doesn't consider any security measures the manufacturer might have put in place specifically to prevent such a thing.

Note that this is basically the same problem as any problem were you are considering reprogramming a bespoke system made by someone else.

[SwissProgrammer]

I think that the correct answer is probably "Yes". The correct comments are probably covered by "The common passenger vehicle can be programmed completely in C++." How is probably answered by "Access the chip that holds the current program. If that chip is burnt in and unchangable, get a blank chip of the same type and write to it then replace the old chip with the new one." As to the warranty: I and most other people looking to do such do not need or even want the manufacturer's warranty."

I have been studying this and the previous seems to be what I am finding suggested by shop mechanics, etc.

Thanks Banfa. You are still one of my favorite guru's here.

[SioSio]

Reference information.
TRON is widely used in Japan.

[Banfa]

You are right the absolute correct answer is yes, if you are willing to hack the hardware* then you can almost certainly find a way :-)

But you will have to put in the work and there will be quite a lot of it.


* and don't care about the warrantee

[SwissProgrammer]

Banfa says it can be done, and SioSio gave a reference. I am accepting that as fact.

SioSio:
I searched TRON and C++ and auto, etc. and I am not clear that I have usable results. Would you please point me to a description of the TRON that you are referencing? Please tell me where to get it and maybe a link to a users manual?

Thank you.

[Banfa]

1 last word of advice, if possible be non-destructive, so if you are removing the flash chip to replace it do it in a way that leaves it so you can put it back, if you are just going to programme over the top of it take a copy of it first etc.

Not because you ever intend going back to that state but because sometimes in these endeavours you realise you needed to know how it was working before.