[BMW DIY Guy]

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Hey yall..

This is an odd one and I am still tryign to figure it out what is going on, but thought I would share.

Saturday, rolled the car out into my steep driveway and locked it. 30ish seconds later the alarm goes off.. ok.. odd.. unlock and relock and wait. 30ish seconds later it goes off again. (Rinse and repeat about 4 times, same behavior). I write it off as just odd, never done it before but maybe the angle sensor on the alarm is juuuuust at the right angle who knows what.

Sunday, all day unlocked in the garage no issues.

Monday, errands, driving around, locked multiple times on a flat surface, no issues.

Today, locked and walked away on a flat surface and the alarm goes off again. Unlock and lock, rinse and repeat 3 times with still issues before I just take her home into the garage and left unlocked. I will fiddle more locking and unlocking here at home to test, but this is just odd.

I am sincerely confused and of course can take it to the dealership to check but we all know sporadic issues that don't throw codes are SO MUCH FUN to take into Service.

Anyone else seen this behavior?

[ESB]

Do you by chance have something connected to your OBD port? I remember reading on F87 forums once that this couuuld sometimes be the cause of alarm going off randomly.

[BMW DIY Guy]

Originally Posted by ESB

Do you by chance have something connected to your OBD port? I remember reading on F87 forums once that this couuuld sometimes be the cause of alarm going off randomly.

NICE!! Yes I do! I have my wireless adaptor in there for some coding, and will remove it immediately.

Thank you, great thought!

[ESB]

Fingers crossed for ya but no promises!! I’m just spreading rumors lol. I have one plugged into my F87 and don’t have issues so 🤷‍♂️

Maybe something with more knowledge will know if there’s diagnostic software or something that can have the car spit out the reason for alarm going off or something like that.

[ExplodingFires]

Originally Posted by ESB

Fingers crossed for ya but no promises!! I’m just spreading rumors lol. I have one plugged into my F87 and don’t have issues so 🤷‍♂️

Maybe something with more knowledge will know if there’s diagnostic software or something that can have the car spit out the reason for alarm going off or something like that.

You’re correct! There is an alarm for when something’s is kept plugged into the OBD port. I believe there is even a coding option (though I don’t remember where it is) to disable the OBD alarm so they can keep the adapter plugged in at all times.

[rons e92]

I had the same thing happen a few weeks ago. I was at an event in PA and my alarm kept going off when I was no where near my car. I wondered what was causing it, but it didn't happen after we left the event. Yesterday was one month since I've seen the car, so not much opportunity to keep experiencing it.

Interesting to hear it happens when something is plugged into the ODBII. I definitely had something plugged in that day, although I usually have an ENET cable plugged in and wrapped up sitting in the door pocket ready to connect to the laptop if I need to.

[RockCrusher]

Originally Posted by BMW DIY Guy

NICE!! Yes I do! I have my wireless adaptor in there for some coding, and will remove it immediately.

Thank you, great thought!

What ESB said.

From my M2 owners manual:

The alarm system issues a visual and acoustic signal when someone attempts to open the locked vehicle incorrectly.

General information
When the vehicle is locked, the vehicle alarm system reacts to the following changes:
▷ Opening a door, the hood, or the cargo area.
▷ Movements in the interior.
▷ Changes in the vehicle inclination, such as during attempts at stealing a wheel or when towing the vehicle.
▷ Disconnected battery voltage.
▷ Improper use of the socket for OBD on-board diagnostics.
▷ Locking the vehicle while a device is con- nected to the diagnostic socket.

The alarm system signals these changes visually and acoustically:
▷ Acoustic alarm:

Depending on local regulations, the acoustic alarm may be suppressed.
▷ Optical alarm:
By blinking of the hazard warning system and headlights, where required.

Do not modify the system to ensure function of the alarm system.


I'll add I had a new Porsche Boxster that set of its alarm at random times. Long story short in leaving the top down a small moth set up housekeeping in the car. Would come out and fly around and this would set off the alarm. This would happen at work. Or sometimes at home with the car in the garage.

Had no clue what was going on until one day with my in the car the moth come out of its hiding place. Then the light dawned...

From then on I was on the alert and finally one day got the moth.

No more alarming.

Lesson? I never ever again parked the Boxster with the top down or the windows down, even in my garage.

And I always lock my car when I walk away from it. This to ensure the car's electronics go into their lowest power mode promptly.

[BMW DIY Guy]

Two days of the obd wifi adapter unplugged and no repeat issues. Thanks yall, really appreciate you!

[BMR.WRLD]

My car is completely stock and I've had my alarm sound off WHILE DRIVING. That is wild, never expected that.

[KC87ZB]

By the way, you can code out the OBD port activation of the car alarm using bummer code - if you choose. It’s in the Roof Function Center section

[BMW DIY Guy]

Originally Posted by KC87ZB

By the way, you can code out the OBD port activation of the car alarm using bummer code - if you choose. It’s in the Roof Function Center section

No issues once the adapter was removed, and this is awesome! I will code this out today.

[M2siast]

Glad somebody knew the answer and helped you out appropriately.

Having an alarmed OBD port is a security feature, as someone can use it to bypass the cars security measures via OBD.

If you are dead set on keeping an OBD adapter constantly plugged in, you can disable the OBD alarm, so you can keep it plugged in all the time.