This is a genuine BMW carrier relay, part number 12 90 1 437 378. The number stamped on the part is 12901437378; BMW's catalog files it under the short number 1437378. You will find it on our Electrical shelf, under Other Engine Electrical System parts.
It fits every E46 body style (320i, 323i, 325i and 328i, 1999–2006), with the M52, M54 or M56 engines — and the European-market versions.
BMW draws it on 3 diagrams, among them Control unit box (12_0899) and Control unit box (12_1140). It weighs about 40 g (under 0.1 lb).
We have not had one on the shelf yet. Request it and we will tell you when one comes off a car.
