I phoned BMW and the guy in the parts department wasn't sure. He just said he looks like a Bosch but he can't 100% confirm. Doesn't anybody know? Apparently Bosch/Siemens ECU's were used for the R53's - just not sure on what year they changed over.

 

If you take it out (which is very easy) it sould say on the case. From my reading I've only heard about the Siemens ECU, no mention of Bosch.

 

I've heard mention of Bosch ECUs being used, but here in the US all the older cars I have seen have always been a Siemens.

 

Siemens ECU

 

Siemens EMS2000 to be exact.

 

Thanks guys!