Alarm de-activated, how to get it back??

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Joined: Tue 16 Sep, 2014 19:45
Posts: 58

  Z3 roadster 2.2i

Alarm de-activated, how to get it back??

Post by Gordon13 » Wed 04 Mar, 2015 19:51

Went to my garage last weekend to check up on the Z

The battery was flat, except for enough juice to put on the interior light.

So, simple, remove battery take home and trickle charge.

Well, not quite. The alarm goes off as soon as the battery is disconnected. Got the jump leads and unlocked it properly with the key fob, disconnect battery and the alarm goes off.

A bit of ferreting in the hand book shows how to de-activate the alarm by unlocking the drivers door with the key and with the alarm sounding turn the ignition to position 2. This unlocks the whole car and kills the alarm, all good battery on charge.

I'm now wondering if there is a procedure I need to go through to re-activate the alarm or will it just all be OK?

It's a 2002 with the black 3 button key fob

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Robert T
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Joined: Mon 12 Jun, 2006 11:35
Posts: 10021

  Z3 roadster 1.9
Location: Cheshire

Re: Alarm de-activated, how to get it back??

Post by Robert T » Wed 04 Mar, 2015 21:42

The later is alarm is generally a lot more resilient to battery removal than the early one with the separate fob - the problem of having to re-sync the alarm usually only arises when the battery in the key goes flat.

Note that with the later alarm, the immobiliser chip can also be used to reset the alarm as you did by putting the key in the ignition, and this works even if the battery in the key is completely dead.

I don't recall ever having to unset the alarm a second time when I disconnected the battery, but I had the car unlocked when I did this. The alarm should not be set if it is opened with the remote, and you can still lock the car with manually the key, leaving the alarm unset, so I don't know why your alarm is sounding. I should probably go and check that my siren is still working. :lol:

Cheers R.
Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc

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