Anti-Theft Alarm goes on when I lock the doors and leave it for few minutes! - The Unofficial BMW M5 Messageboard (m5board.com)

wyvern · 19th February 2008, 14:32

Yesterday I was driving to work. I parked my car and locked the doors using the remote, walking away from the car to my office and suddenly I hear the car anti theft alarm goes on with the hazard signal. I come back and unlock the door and everything is fine. Again walk away and the same problem occurs and the alarm is triggered. It did it 4 times and I was late for work. I left it finally hope that it will stop. Eventually it did stop.

Then I left work going to home and it happened again then stopped. That was the last time it happened (Yesterday). I will have it checked by the dealer, just curious what can cause such thing?

Any help will be appreciated guys

Thanks

DouglasABaker · 19th February 2008, 15:56

It is one of several things:

The motion sensor is out of adjustment,
The tilt alarm is out of adjustment,
You bonnet sensor is out of alignment,
Your battery is weak and triggering a low voltage condition.

It could also be your doors/boot, but presumably you'd see the lights remaining on in the car after you close the doors.

Trying disabling the motion / tilt alarm by pushing the lock button 2x. That will at least narrow it down!

d-

Respect the M · 19th February 2008, 18:40

My money is on the motion sensor, maybe dirty or obstructed.

As DouglasABaker said:
Trying disabling the motion / tilt alarm by pushing the lock button 2x. That will at least narrow it down!

RoundelM5 · 19th February 2008, 18:52

Had a similar problem and many others have too - in many of our cases it is the hood sensor...see post #4

Alarm sounding and Peake Code Reader

wyvern · 19th February 2008, 22:10

Thank you guys for your continues support. I parked my car that day on incline. And had the sun shield in front glass + the battery is weak as from my last service the dealer noticed that when he started up the car. I will have to check which one did cause the problem.

Thanks again guys

emccallum · 19th February 2008, 22:29

Did you leave someone locked in the car?

jclyman · 20th February 2008, 02:24

Check to make sure the hood (both sides) are completely closed.

IRISH M5 · 6th June 2008, 16:30

Having the same issue as the OP since yesterday and I am following the advice in this post. Will keep you updated if something different turns out to be the cause.

doc$holliday · 6th June 2008, 21:00

As stated above, the hood sensor is a major culprit for this, mostly if you live in a hotter climate. My alarm was going off randomly during the daytime only as the temps started heating back up here in South Florida...sure enough, yanked that hood sensor out and all is quiet. The system thinks the hood is permanently closed so your alarm is satisfied.

Got a new sensor on order, it's about $15:
BMW #61314158205

good luck!

SP

IRISH M5 · 6th June 2008, 21:24

Interesting in that we have just had two 92F humid steamy days. I did jiggle the hood sensor and also dusted around the motion sensor and it has not gone off since.