5-Series (E12,E28, E34, E39, E60)Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)
Hi there, I just picked up my 98 540i last week and had the car alarm go off at 3:30 AM this morning. I don't recall ever having my previous car alarm go off, and in the past 6 day's of ownership I've never had the 540 alarm go off until just now.
I was wondering if others got false alarms or if I need to worry that someone is already after my new baby.
Mind you I live on a 1.5 acre lot on a country road (rural Pennsylvania), upscale neighboros and the car is on a 500 foot driveway not near traffic or any other disturbances.
Is this just early morning paranoia or should I be concerned.
Don't be concerned....Lock your car as usual then look at that little red blinking light (under rear view mirror) press the lock button (on the key) TWICE..note each time you press it, the red light goes solid....as such the alarm won't go off-providing you have a good battery and no drop in voltage//over night.....
Same results can be achieved if you turn the key clock wise TWICE on the drivers side.....red light will go solid on each attempt....this is your motion sensor!
not sure exactly what causes this complaint but i have herd of a few cars at work having this problem. however i DO know that low battery voltage can really mess around with the computers. because there are so many of them and that they all need a proper amount of voltage to operate correctly a low batter has been known to do all sorts of crazy things.
and if you take it to the dealer be patient with them these sorts of problems are hard to fix becasue they happen so sporadically and sometimes no faults are storred in the computer either. but if you don't know how old the battery is then i'd have it atleast tested to see what kind of condition it is in. and if the battery has ever gone dead that greatly compromises the performance of the battery.
also another thing. i can't imagine a whole lot of movement in the garage at 3:30 in the morning but i have run across instances where people pull thier car in the garage and lock the car then they close the garage door and the alarm goes off. it was tracked down to the motion of the door being closed tripping the motion detector inside the car. just something to think about.
one thing that is fairly common and easy to narrow down is the hood switch. I have seen several cause the alarm to go off. It can easily be checked by just unplugging it for an evening or 2. If the alarm doesnt go off with t unplugged then you have your problem. Also as I think Bill mentioned the FIS (interior sensor) is another somewhat common problem. As Bill mentioned by pressing the lock button on the remote 2 times within 6 secs it bypasses the FIS sensor and the tilt sensor which is another good way to narrow it down. Lastly, the dealership does have equipment which can access the alarm counter which will tell them exactly what sensors have been triggered and exactly how many times each has been triggered which makes it fairly easy for them to nrrow down and diagnose.
Thanks for all the reply's. I also stopped by the local dealer to get some wheel spray, and locking wheel lugs (can't believe the car didn't have any), and we discussed the problem as well.
His answer was that he remembers a lot of the E39's having the motion sensor go faulty and become hyper sensitive or intermittently give off a bad alarm. He stated they used to replace a lot of them.
I am having them go over the car next week as a preventative measure, to find anything that may be in need of replacement or things that are ok, but I should keep an eye on and will ask him to check the battery too. (I'm sure this is akin to giving them a blank check, but I'm still interested to hear what they find.)
I figured it was late night paranoia, but when I finally own one of my few dream cars (Lotus Esprit, Ferrari 308, and Porche 911 late 80's version are my other dream cars) I've become awfully protective of it. LOL
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