Possible to use BimmerCode to disable alarm system?

[sepiadreamer]

I know you can turn off, for example, tilt and interior sensors but can the alarm be completely silenced with either the "panikalarm" or "stiller alarm" settings in Alarm System>3002 DWA? Guess I'll find out when my OBD scanner is delivered but while I'm waiting I thought I'd ask if anyone here has tried this.

 

[jadnashuanh]

Do you want to just silence it, or actually disable the alarm function entirely? If just silence it, but retain the locked and anti-theft portion, you might be able to just disable the (dedicated, I think) horn.

 

[sepiadreamer]

Between silencing it and completely disabling it, either would be great. I've already had the siren physically disconnected but in that situation the alarm system just uses the horn instead, and of course the horn can't be disconnected for safety reasons.

 

[jadnashuanh]

My guess is that the computer looks to see if the siren is actually present and likely just uses a resistance (current flow) test to verify. So, just like you may need to do for substituting an LED bulb to keep the system from faulting that there's no bulb there, if you put a load resistor across the leads, it would likely think it's there and not switch to the horn.

This switching of functions is part of many BMWs, and probably other cars. If the car senses that the normal brake light(s) are out, or the rear hatch is open, it will activate the bulbs in the bumper to ensure there's rear lights and brake light functionality.

By leaving the alarm functionality (less the sound) active, if someone were to break in, it would still disable the car from running.

FWIW, if you're trying to do this to enable you to keep a pet in the car while you make a quick visit to the store, you can disable the internal motion sensor, but leave the rest of the functions active. That's discussed in the owner's manual.

 

[sepiadreamer]

Good idea about the load resistor, thanks. What BMW told me was that although it was possible to disconnect the siren, it couldn't be physically removed from the car, so I wonder if there'd be some logistical issues with wiring something like that up. I never got an explanation as to why the part couldn't be removed.

No, it has nothing to do with leaving a pet in the car. As I mentioned previously I believe it's possible to permanently disable the interior motion sensor with BimmerCode.

 

[sepiadreamer]

I enabled silent alarm and disabled panic alarm with BimmerCode and so far at least the key fob panic button no longer sets the alarm off.