Mend > Car Alarm Systems

My bmw car alarm keeps going off?

My bmw car alarm keeps going off when i lock the car with the remote fob but not when i lock the car with just the key can anyone tell me what they think might be the problem and assist. it is a bmw 318 convertible 2002

matthew english
August 2007

BMW BMW 318 Security Systems, Car Alarm Systems Alarm Lock Key

I had the same problem with my 2000 X reg 320Ci conv. It turned out to be the bonnet (hood) sensor switch. I took it apart, give it a good clean replaced it and everything's been ok since. Apparently, it's another common one.

Dvd
April 2008

This is probably a known fault with convertibles its the interior sensors that are faulty and trigger the alarm sporadically. your local agent will be able to read the alarm ecu trigger counter and verify this only action is to replace for later versions.
You can allso disable interior sensors by pressing "lock" button twice when locking vehicle (may invalidate insurance etc as sensors are there for a reason) this allso turns off the tilt sensor if fitted so if someone trys stealing your wheels no alarm!
as last note large metal objects set the sensors of ie garage door if parked close by.

ian.
September 2007