CAN Bus Switch: Get Help & Functionality Now!

Hello fellow CAN hackers,

I stumbled upon this forum by chance and I'm very impressed so far. Unfortunately, I have very little experience and knowledge about the topic of CANBus... And to gain that, it probably takes months well, slowly but surely, the squirrel is getting fed, or something like that?

Just a quick introduction about myself: My name is Christian, and I'm a trained IT systems electronics technician. Since I'm only interested in the CAN bus in my private life (my car), my experience is very limited, as mentioned above. Definitely not a CAN hacker yet, but what isn't possible today might be possible tomorrow .

I hope you might be able to support me a little bit.

Of course, I already have a question/request. *G*

'I have a BMW 1 Series where I've enabled the US side marker lights (turn signals that stay on constantly) through coding. This is not allowed in Germany, but I would like to have them on for show purposes, only it's annoying to have to take out my laptop and reprogram the control unit each time. It only takes 5-10 minutes, but I would still prefer to avoid doing that.'
Therefore, my idea is to build a switch/button that, when activated, would essentially 're-program' the respective control unit (in this case, FRM/NFRM, if that means anything to you). I basically got this idea from a colleague's Audi; his A3 has a DRL switch that allows him to turn the daytime running lights on or off. While I don't know how the switch works, I suspect it also re-programs something in the car's control unit. It probably doesn't work with an analog signal and simply activate an additional lamp in the headlight.

My question to you is: Is something like this feasible? And if so, how exactly would it be done?

I hope you can help me, and I was able to express my concern; I've never been good at putting things into words .

Regards,
Christian.

To my knowledge, the daytime running lights (DRL) in Audis are switched using an analog signal. The signal goes from the light switch to the body control module, which then controls the lamps accordingly.

With Audi, no reprogramming is necessary.

In your case, you need a microcontroller with a CAN interface that reads your switching signal and then automatically encodes it via the CAN bus. The question is whether it might be simpler to just power the turn signals directly with the switch, so they would stay on continuously.

Thank you for your reply.

Okay, I thought they would have found a more elegant solution .

Theoretically, it's possible to simply power the turn signals with a switch, but the problem would be that the lamp monitoring system would have to be disabled, otherwise an error message would be triggered. Furthermore, there would be an undesirable effect if you forget to turn it off, because then the turn signal would be very difficult to see due to the headlight's constant background illumination in the same color.

If you modify the control unit, specifically through coding, the control unit will take over and disable the side marker function on the corresponding headlight during the flashing process.

If you think the whole thing is too complex, I would definitely simplify it. It's not worth spending weeks on it, since, as I said, I can do it with a laptop or even a phone in 5-10 minutes.