Alarm going off every night

[Chrisgillett]

This is an odd one. My car alarm has gone off in the evening three days running now. Not exactly the same time but between approx 8 and 10pm. Sometimes more than once. I work from home so know the car alarm hasn’t gone off during the day. I’ve checked the doors and windows and boots etc and can’t find anything obvious. The car has been used every day for short journeys so has moved about
Edit. M3LR 2020

Any ideas?

 

[ewoodrick]

You may want to turn Sentry mode and see if you can get some video.

 

[BongoFury]

My 2022 RWD did the same for a couple of days, I reset the car and it hasn’t done it since (so far, it’s been a month).

 

[GlynG]

Typically when this happens its a spider or fly within the car and triggering the internal sensors.
You can eliminate the sensors triggering the alarm to confirm they are detecting some movement - just put some tape over the sensors so they cant detect anything, The sensors are in the roof bar - they look like USB C sockets - two of them, you see them if you sit in the back seat and look upwards.

If doing this silences the alarm then time to get the hoover out and give it a damn good clean.

 

[Doudeau]

Typically when this happens its a spider or fly within the car and triggering the internal sensors.
You can eliminate the sensors triggering the alarm to confirm they are detecting some movement - just put some tape over the sensors so they cant detect anything, The sensors are in the roof bar - they look like USB C sockets - two of them, you see them if you sit in the back seat and look upwards.

If doing this silences the alarm then time to get the hoover out and give it a damn good clean.

I agree with this. I’ve had this a few times over the last 3 years and found either a spider or….. particularly if the alarm has gone off at night…… a small moth that woke up at night time.

 

[Masklin]

If it’s a fly or spider that’s difficult to track down, using an air conditioner cleaner such as one of these will solve…

A/C Pro Auto Air-Con Cleaner | Halfords UK

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www.halfords.com

 

[Chrisgillett]

To close this thread out. The alarm went off four nights running and then hasn’t since. I assume it was an insect of some sort.

 

[MrBadger]

To close this thread out. The alarm went off four nights running and then hasn’t since. I assume it was an insect of some sort.

I wouldn’t rule out a bug

 

[Silicon Desert]

I wouldn’t rule out a bug

yea, sounds like the car has a software bug with bugs

 

[BushtrimmmerJr]

I had this issue (2020 M3) on a few occasions over the last few years and as others have said it was usually down to a bug. Having said that we had another spate of false alarms earlier this year and when no bugs were found I put in a service request. It turned out a connector was completely corroded due to water ingress from the roof. Known issue by the sound on those earlier models and once fixed I didn’t have the problem again.