Frequently Asked Questions - BMW M coupe Alarm System
What is the part number for the screw cap covers for glovebox screws?
51-16-1-949-793 screw cap covers
The factory alarm kit came with the wrong bolt to hold the siren to the bumper?
You will need to get a M6x30mm bolt to connect the siren to the bracket.
Why does the factory alarm not activate and chirps three times, after having replaced my factory radio with an aftermarket?
3 chirps means that one of the alarm circuits is open. There is a thick gray plastic pin on the back of the original BMW head unit. This pin engages in a "socket" in the dash when the head unit is installed. There is a sensor in the socket that detects the presence of the pin. If the alarm is armed and the pin (radio) is removed the alarm will sound. The other side to this is that the alarm will not arm if the pin is not engaged. The pin unscrews from the back of the BMW radio. You should be able to figure out how to attach it to your new head unit or this "socket" needs to be tripped by your installer so the alarm system thinks that the radio is installed.