Car alarm - false alarms

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ericblz

Well-known member
Joined
Jun 13, 2014
Messages
62
My car sits in direct sun all day (Southern California). Makes me wish it had solar panels on the roof since we don't get sunroofs. I mention this since someone at my office brought up heat as a possible cause.

Anyway-about every second or third day the alarm goes off. Sometimes I see a person walking within 20 feet but usually it is just sitting by itself. No loud jet planes or explosions nearby that I can tell.

I wouldn't mind completely disabling the alarm. Should I just disconnect the siren? Stuff an old sock in it to at least quiet it below 100 dB? Rumor has it that pressing the lock button twice on the remote disables the alarm but have not tested that idea.

My question is if anyone has experienced regular false alarms and options recommended. Thanks all!
 
ericblz said:
My car sits in direct sun all day (Southern California). Makes me wish it had solar panels on the roof since we don't get sunroofs. I mention this since someone at my office brought up heat as a possible cause.

Anyway-about every second or third day the alarm goes off. Sometimes I see a person walking within 20 feet but usually it is just sitting by itself. No loud jet planes or explosions nearby that I can tell.

I wouldn't mind completely disabling the alarm. Should I just disconnect the siren? Stuff an old sock in it to at least quiet it below 100 dB? Rumor has it that pressing the lock button twice on the remote disables the alarm but have not tested that idea.

My question is if anyone has experienced regular false alarms and options recommended. Thanks all!
Click to expand...

There are two main events that will trigger the alarm -- one happens if the doors are opened, the other happens if motion is detected inside the car.

In BMW's in general, there have been issues with the interior motion sensor giving false alarms. Sometimes because of dogs or other pets left inside the car, but other times because of ghosts and gremlins. Maybe even because of SoCal heat rays?

You might see what happens if you start regularly disabling the interior motion sensor. Check your manual to be sure, but I believe the procedure for doing so is to use your key fob to lock the car, then once it's locked press the lock button on the key fob again and hold it for a couple of seconds.
 
tiburonh said:
ericblz said:
My car sits in direct sun all day (Southern California). Makes me wish it had solar panels on the roof since we don't get sunroofs. I mention this since someone at my office brought up heat as a possible cause.

Anyway-about every second or third day the alarm goes off. Sometimes I see a person walking within 20 feet but usually it is just sitting by itself. No loud jet planes or explosions nearby that I can tell.

I wouldn't mind completely disabling the alarm. Should I just disconnect the siren? Stuff an old sock in it to at least quiet it below 100 dB? Rumor has it that pressing the lock button twice on the remote disables the alarm but have not tested that idea.

My question is if anyone has experienced regular false alarms and options recommended. Thanks all!
Click to expand...

There are two main events that will trigger the alarm -- one happens if the doors are opened, the other happens if motion is detected inside the car.

In BMW's in general, there have been issues with the interior motion sensor giving false alarms. Sometimes because of dogs or other pets left inside the car, but other times because of ghosts and gremlins. Maybe even because of SoCal heat rays?

You might see what happens if you start regularly disabling the interior motion sensor. Check your manual to be sure, but I believe the procedure for doing so is to use your key fob to lock the car, then once it's locked press the lock button on the key fob again and hold it for a couple of seconds.
Click to expand...

It should also be noted that FedEx and other radio-signal handhelds will trigger alarms on older BMWs. My 04 545 used to sound off every time the FedEx guy left our building. Also, loud exhaust systems (on Harleys etc) will also trigger them. So, you may want to look and listen around your parking area for external clues as well.
 
Not to wake a two week old post, but on the i3s the alarm will also go off if you have anything plugged into the OBD port. We have been seeing customer's complain of this when they have the insurance "snapshot" devices plugged into the ports.

I read a Euro document saying BMW enabled this OBD monitoring function as an extra level of protection against software-based carjacking.
 
Same experience here. I own a software development company, we write a lot of GPS tracking software. To generate live data for testing, occasionally I plug one of our commercial cellular trackers (same ones used by UPS) into the OBD port before I leave the house. When I get to the office, if I try to lock the car, the alarm goes off immediately. If I then disconnect the tracker, the alarm is fine.

I've also experienced this a couple of times after coding the car, even though my OBD cable was already disconnected. Power-cycling the car a few times restored the alarm condition to normal.

It's touchy.
 
There's a reason why BMW says the OBD port is only for qualified users! The i3, and most modern cars, are essentially huge networked computers...they don't like intruders!

The i3 also has a tilt sensor...I know because mine ended getting locked as I was jacking it up. It looks for changes in the body angle, not just simple movement.
 
Bringing this thread back to life. This is our 4th bmw product with an alarm. In our 2006 330i and 2008 mini cooper, we could leave the windows cracked or roof open and set the alarm. No false alarms. Our 2011 mini cooper and 2015 i3 will sound the alarm within minutes of locking the car if the windows aren't completely shut. It's not just us. We laugh all the time when we're at malls or parking lots and hear the familiar alarm sound and say "that's a bmw" and sure enough, it is. In the mini, the dealer was advised to put a thick black piece of foam over the interior ceiling grille cover in front of the alarm sensor and that helped quite a bit. It's frustrating in the i3 as I like to keep the windows cracked in order to keep the car from heating up.
 
Helps if I read the manual. LOL

Press the lock button on the remote within 10 seconds of the initial lock press and the clown nose will light for 2 seconds indicating the interior motion and vehicle tilt sensors are deactivated.
 
While not particularly convenient if you're only going to be stopped for a short while, but I've found that the i3 Climate Cover really does make a huge difference. I found it on-line for about $75 off list (it's still expensive), but the car's interior really does stay near ambient when sitting in the hot sun. This is even a better situation than the tint I have (3m Crystalline), which does a very good job of rejecting IR. Having the reflective surface outside verses inside means that the glass doesn't heat up and become its own radiator, not counting the black roof panel.
 
GodFollower said:
Not to wake a two week old post, but on the i3s the alarm will also go off if you have anything plugged into the OBD port. We have been seeing customer's complain of this when they have the insurance "snapshot" devices plugged into the ports.

I read a Euro document saying BMW enabled this OBD monitoring function as an extra level of protection against software-based carjacking.
Click to expand...

YES! i can second this. i've been trying to figure it out all day and that's the one thing i did was plug my metromile unit into the OBD port. smh.
 
GodFollower said:
Not to wake a two week old post, but on the i3s the alarm will also go off if you have anything plugged into the OBD port. We have been seeing customer's complain of this when they have the insurance "snapshot" devices plugged into the ports.

I read a Euro document saying BMW enabled this OBD monitoring function as an extra level of protection against software-based carjacking.
Click to expand...
This security can be disabled by changing a module parameter value (a.k.a., coding). This would allow the use of a Metromile dongle or other OBD driving monitors.
 
Hello
This topic is of interest to me. I will be getting my "new to me" 2014 i3 next week. I do not wish to repeat the experience that I had last summer when I bought a 2000 Porsche 911. That car's alarm went off all the time, and the final fix was to unplug the alarm horn.

Getting back to the first poster's question:
"My question is if anyone has experienced regular false alarms and options recommended."

Any experience here?

Can anyone tell me where the alarm sirens are located? Or should I just set off the alarm and find out the hard way?
thanks
Doug
 

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