2003 540 Alarm issue

[John Clay]

Just started happening a week or so ago. Pretty consistently (it's probably going off in the parking garage right now) my alarm goes off a few minutes after I leave the car. Always just once - Alarm goes off, I unlock the car, relock it, and it doesn't go off again.

Any ideas on where to start?

[Jase007]

Car Battery on its way out.

Happened to several E39 owners I know.

Confirm with load / voltage testing.

Check terminals / clamps / grounds.

* Also, check to see that your HVAC cabin air sampler fan ... the one in the HVAC head unit, isn't still running (it's quiet) when key is out and car off. These are notorious for killing batteries b/c a FSU (final stage unit) in the center console fails. Easy DIY if this is the case, can post more later.

[John Clay]

Started happening a bunch more over the last few months. Finally got a chance to look into it more last week. Simple fix, there is a switch that turns on a sensor for the hood when the hood is shut. Unplugged the switch, and the alarm has not gone off for a week.

[roundel]

Unplugged the switch

Now that your alarm is disactivated, where do you park your car?:twisted: