[pilothobs]

Hello Everyone,

As you can see I am new to this forum. Have been interested in building a EV since around '98 and have never had the time (or money).

My biggest question is how everyone deals with the electronics for the car. obviously, don't need an ECU per say but what about getting all the dash lights to work.

This is especially true in a BMW where they have a BECM unit that is tide to EVERYTHING.

Thanks for having me.

Happy new Year !!!



Hobs

 

[madderscience]

If the target conversion vehicle is new enough to use CANBUS for controlling major parts of the car, this can be a challenge. And as you allude to, different vehicle manufacturers are better or worse about modularization of their electronics. In the case of my 2004 scion, removing the ICE ECU caused a couple check engine lights to come on but otherwise everything works. But most of the body stuff in the scion is still discrete wired.

The newer the car, the bigger the challenge usually.

Best best is to search out communities that are hacking vehicles like yours and try to get a feel for what you would need to do to keep it working. Perhaps it would be enough to leave the ECU in place and let it scream about an engine that doesn't seem to be there, but hopefully it still can measure wheel speed (often taken off of ABS ring sensors) and run the peripherial stuff. You can remove/disable warning lights that are no longer meaningful, unless its an LCD display or something.

Good luck.

 

[CKidder]

Hello Everyone,

As you can see I am new to this forum. Have been interested in building a EV since around '98 and have never had the time (or money).

My biggest question is how everyone deals with the electronics for the car. obviously, don't need an ECU per say but what about getting all the dash lights to work.

This is especially true in a BMW where they have a BECM unit that is tide to EVERYTHING.

Thanks for having me.

Happy new Year !!!

Hobs

What people usually do is capture the CAN traffic from a working, running, driving car and then try to figure out what that traffic means. If you can interpret the signals that go to your dash then you can fake them when the engine is removed. This may or may not make the car's electronics happy. As madderscience said, the newer the car the more likely it is to through a huge fit if you remove things. At the worse you end up removing pretty much all electronics but the dash and you spoof signals to the dash to make it work. This is OK for engine control stuff (you don't need to control an engine that isn't there) but really isn't acceptable if you end up having to remove things that control ABS brakes, traction control, or body control modules. You sure hope that those things will agree to work anyway but they might lock out if the engine seems to be gone. You can, once again, spoof the engine traffic. People do this. But, it really is a huge amount of work and tends not to be worth it for one vehicle. If you are doing a single vehicle conversion you are much better off going old school. Find a vehicle from 2005 or older. At 2006 CAN was mandated for OBDII and thus is also more likely to have been used in the engine and body control systems too. But, it depends on the vehicle manufacturer too. Mercedes Benz has a really close, buddy/buddy relationship with Bosch (the originators of CAN) and used CAN controlled ECUs all the way back into the late 80's. I have some 1990's Mercedes where the car has about 8 ECU modules all lined up in a giant housing and they all speak CAN to one another. You would not want to convert such a car to electric drive. It just has too many things all tied tightly together. Modern cars are just like that but perhaps worse. Heaven helps anyone who attempts to convert a 2017 vehicle from ICE to electric.