Alarm retrofit has gone horribly wrong..

[Qsilver7]

Originally Posted by upallnight

Very Interesting, didn't know they used different frequency between the US and Europe. If he brought the alarm module from a US seller that could be the reason.

Yep, 2 frequencies are used...and if the writing has been rubbed off...you should see 315 MHz or 433 MHz written on the back of your key. And the antenna amp located on the tail gate (seen in pic in post above) will also have its radio frequency printed on its label.

And there's one more option...and that's the IR (infrared) remote key (BMW part # 51 21 8 374 933). Some markets still use IR remote lock/unlock. Again, this will be identified on the key (if the writing hasn't been rubbed off).

If you have a relatively unused spare...you may have to refer to it for the RF/IR info.