I have a 2002 Mini Cooper S with less than 100K. Fixing it up, since it had water damage from the sunroof drain being plugged and leaking into the car from the previous owner. She claimed that the car (being a stick, manual) would start by itself! She didn't to pay for fixing it so I bought it. I took the seats and carpet out and dried everything. Took the body control module out and dried that as well. Everything seems to be going well, but the car does not want to shut off even when I take the key out. Sometimes the fan will stay on as well with the engine and at other times it might turn off. I have a hard time believing that it's the body control module itself. Could it be something else? I don't mind buying a new body control module and reprograming it to the car, but I have a feeling that is not it. Its something else that perhaps got "wet". The car was not flooded, it was just in flooded under the seats and got he body control module wet. The water was never up to the dash. Just to the sills of the doors. Any suggestions would be great! Thanks!

 

I don't know anything about it, but a couple of times I have tried to shut it off before putting it in park. Maybe some short somewhere has fooled the car into thinking it is in gear?

 

Your gen1 mini (2002 to 2006 hardtop) is a rather interesting car!! Seems to have a mind of its own....
the kwy has a rfid chip in it, that the computer must "see" to let the car start....it is apparently seeing the (so the imoblizer appears to be doa, but might be better than never seeing it...resulting in no start....).
Since the water ran down the ipillars, dripped down the wiring bundles like a wick....for all intents an purposes, the car was like it was underwater ...any plug is kinda suspect.....
a suggestion....the bcm might be good, but minerals etc might be frying it...so use distilled water...rinse it out...dry it throughly....and maybe it will come back. While in there...check every plug, connection you can find, unplug, clean, then reassable with a dab of electrical grease...you might still get lucky.
One other thing...
Please look on the drivers side door jamb, and post the build date....some of the 2002 early production mini's varied signifigtly from later cars in quite a few ways...this can make mataince and parts, even from mini a bit of a challenge....it was afterall the first few months of a new car getting built in a new factory(kinda) by new workkers and a new company...with parental support from bmw...

 

Reviving this old thread because having the same issue.
06 MCS manual. Tried BCM from identical parts car. Does the same thing. Lights also sometimes stay on when key is turned off. Pulling battery terminal resets everything.