I figured this would be the place to ask my question. What are the differences between an OBD2 M3 wiring harness and an OBD2 328 wiring harness? Or are they the same?

Thanks,

Jake

The harnesses may have similar pin outs, but usually never the exact same, to find out what you can do is take the vins from both cars and lookup the part numbers for the harnesses, sometimes you can get lucky if the years are close, they will match. If not, its fun with wiring diagrams to check and swap pin outs or add wires.

I know someone who has done this conversion. I am only passing on what he told me.

u will need the M3 ECU and the EWS devices. These send the correct signals to the ECU which will allow the car to start.

Far easier than the job I performed on my 318is coupe when I transplanted the M3 into it. With my car being 1992 I discovered that I had to replace the whole vehicle loom. The only part that is still
318 is the shell.

Change engine, change ecu, change EWS transmitters.

Anyone dissagree?