Pulse adapter — a genuine BMW part, number 61 35 8 370 947. The number stamped on the part is 61358370947; BMW's catalog files it under the short number 8370947. You will find it on our Electrical shelf, under Control units, modules.
It fits every E46 body style (320i, 323i and 325i, 1999–2006), with the M52, M54 or M56 engines — and the European-market versions.
BMW draws it on 3 diagrams, among them Switch, cab (61_0972) and Relay, pulse adapter, black (61_4483). It weighs about 21 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.