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RE: E46 Alarm Problem

21K views 11 replies 9 participants last post by  Woowar 
#1 ·
RE: E46 Alarm Problem

Hello.

I own a 1999 E46 323i SE Saloon...

A while back I had a problem where the alarm kept going off randomly for no apparent reason. I worked out that it was the drivers door actuator and so had this replaced which solved the problem..

However it appears that the alarm has started to go faulty again and it's going off at random times for no reason..

I'm just wondering what it could be now.. To be honest I'm fed up with the alarm lol..

I'm wondering if theres a way of locking the car without the alarm being set??? If anyone knows how to do that I'd really appreciate their help..

Thank you
 
#3 ·
If you don't want the alarm you will need to have it coded out by someone with a GT1 or similar machine.

The likely cause of false alarms is the hood sensor, but, to know for sure have the codes for the body control module read and look at the shadow codes. Alarm trip source is stored with # of occurances (up to 31).
 
#5 ·
Alarm

It's a bit hit and miss whether it is the bonnet sensor at the moment but I will experiment with that a bit during the week...

At the moment I've locked the car with the key in the door and the led under the mirror is not flashing... Does this mean the alarm is not set??

Thanks
 
#9 ·
Facelift Coupe (UK ***8211; 55)

Last year (Dec 2011) my e46 developed the dreaded "random" alarm problem. Took it a local mechanic who replaced the siren saying that it looked rusty and was very likely faulty. The bonnet/hood switch was also replaced. Cost me a total of about £200 (£110 for the siren).

Last weekend (Dec 2012) I parked out side a video shop, chose a few movies and came back to a screaming car. Been using the key-in-door to lock the car since before tackling the issue myself and here's how:

(Note there are a lot of forums describing how to remove each of the sensors described so I won't go into those details.)

***8226; Removed the bonnet/hood switch, shut the bonnet, armed the car, waited 30 seconds, ALARM went off .i.e. Not the hood switch
***8226; Removed the tilt sensor in the boot/trunk (above the battery), armed the car, waited 30 seconds, ALARM went off .i.e. Not the hood switch
***8226; Removed the interior motion sensor in the car, armed the car, waited 30 seconds - NO ALARM (possibly this unit, however the car had no sensors at that time either)

Took all sensors indoors, sprayed WD-40 on the bonnet/hood switch to clean it up a bit.
Didn't want to tamper with the tilt sensor. Shook it a bit listening for any loose pieces. No noises.
Removed the interior motion sensor from its casing and simply blew both sides of it to clean out any possible dust.

***8226; Replaced the bonnet sensor, armed the car - NO ALARM.
***8226; Replaced the tilt sensor in the boot, armed the car - NO ALARM.
***8226; Replaced the interior motion sensor, the car - NO ALARM.

To make sure the alarm actually does works:

***8226; Lowered the front windows, armed the car, waited 30 seconds, stuck my hand in through one window ***8211; ALARM!!!!

No parts required. Now that I***8217;ve done it I would say it can be done in 45 mins.
 
#11 ·
The post right before yours should answer your question, NO? :facepalm:
 
#12 ·
I'm sure that locking with the key only inhibits the tilt sensor and the ultrasonics(from the manual). Have you tried the glove box? My M3 alarm kept going off at random intervals until I noticed it went off after I'd been in the glove box. Once closed with force it hasn't gone off since. Might be worth a shot.
 
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