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Alarm keeps going off randomly

Discuss problems you have had or are having with your Z4
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srhutch
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Re: Alarm keeps going off randomly

Post by srhutch » Fri Nov 21, 2014 7:56 pm

bobw1956 wrote:I had my Z4 diagnosed this week, cost £39 inc :?
Diagnosed for what?
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sammysquid
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Re: Alarm keeps going off randomly

Post by sammysquid » Sun Nov 23, 2014 6:36 pm

I had this - was the radio sensor and as above was loose change in the ashtray.

you can use the standard inpa to read the shadow memory to find the trigger - if you are near notts/ derby then I will happy come plug it in for you:)

rabbitsakimbo
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Re: Alarm keeps going off randomly

Post by rabbitsakimbo » Tue Dec 23, 2014 4:40 pm

I had this on an older car and it turned out to be the alarm "backup battery" failing to hold a charge with age, the drop in voltage triggered the alarm , as if it was being tampered with.

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Tommy_hf
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Re: Alarm keeps going off randomly

Post by Tommy_hf » Wed Dec 31, 2014 12:04 pm

Had mine diagnosed as it kept giving false alarms after switching the bonnet pin, turns out it had a higher number of readouts on the interior sensor. To be sure they've reset the counters and I'll have to wait till it gives a couple of false alarms. Most likely it's the interior sensor.

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SamUK
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Re: Alarm keeps going off randomly

Post by SamUK » Sat Jan 10, 2015 1:36 am

Odd..I have a alrarm issue too...

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Terryvision
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Re: Alarm keeps going off randomly

Post by Terryvision » Sat Jan 10, 2015 7:59 am

99% of the time its the bonnet switch, it can be unplugged without any issue... unplug it set the alarm see if it goes off :thumbsup:

If no alarms.... it's your switch :D

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Re: Alarm keeps going off randomly

Post by benlumley » Sat Jan 10, 2015 9:29 am

aj4937 wrote:Hi all, I have recently purchased an 03 plate 3.0l z4 and am having problems with the alarm going off at random times. It is quite frequent and there appears to be no cause. I have read it may be the bonnet sensor and have tried locking the car with the key to avoid turning the alarm on but it still does it. Any ideas what might be causing it? When the alarm does sound it's just the beeping, the lights don't flash and there are no visual signs that anything is happening. I've had to leave my car unlocked for now so I would like to fix it quickly.
Many thanks for your replies,
Aaron
When my alarm plays up from time to time - I lock the car the old fashioned way, key in door, which seems not to set the alarm at all as far as I can tell.
06 Black 3.0si Roadster

Charlesell
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Alarm keeps going off randomly

Post by Charlesell » Fri Feb 17, 2017 8:37 pm

I'm having an alarm problem at the moment too. I have been locking the car on the key for days as it's the only time the alarm doesn't go off. But immobiliser still works.

2.2i SE (ish lol) Roadster. K@N cold air induction, Powerflow twin freeflow exhaust, 18" 255 Deep dish alloys, race clutch,gearbox, tuning and several remaps :)
And Red Grills :)
But me alarms a bitch lol

kevver
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Alarm keeps going off randomly

Post by kevver » Mon Aug 21, 2017 9:46 am

Hi All.
I developed this problem in the last month and as it's not good policy to leave a car unlocked, I thought I would do some research.
Reading this forum and other forums, it seems quite common that the fault usually lies with the bonnet sensor. This can be found at the back of the bonnet between the two diagonal torsion bars. It's similar to the press buttons you would find in old car doors by the hinges.
This is how I fixed my problem:
1. Take out plug on bonnet sensor. Shut bonnet and lock car. If alarm goes off the bonnet sensor is not your problem. If alarm is silent as it should be, the sensor is the problem.
2. Lubricate sensor, plug in and tape down sensor fully. Leave bonnet up and lock car. If alarm goes off, you need to replace sensor (about £25, me thinks). If alarm does not go off, it means that the bonnet is not pressing down hard enough on the sensor to make it work properly. I found that by bending the switch mounting bracket very slightly up towards the bonnet, it solved the problem Don't buy a switch until you've tried this first. :D

baz of eb
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Alarm keeps going off randomly

Post by baz of eb » Fri Aug 19, 2022 9:41 pm

Big time thread resurrection. Just tried this tip today and has solved my issue. Big thanks if you are still around this forum.

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paddy wright
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Alarm keeps going off randomly

Post by paddy wright » Sat Aug 20, 2022 6:21 am

Sounds like a bad battery to me.
Z4 2.2 sterling grey,Msport seats,retrofit cupholders,cruise,footwell lights,sound gen and mfsw,18"ellipsoids,xenons+light washers,ZHPknob,folding mirrors,3"stubby,update wheel caps,gateway300 ipod, wind deflector to keep the wife happy!

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