Factory fitted alarm/immobiliser help....

[charlE30]

My car has the factory fitted alarm/imoboliser?? (oblong fob with blue fabric button and BMW approved written on) and it's stopped working.
The car has been stood for about a month while I've been working on it and the car batt was in need of a charge. How do you replace the battery in the fob?? or is it dealer only job?

Could there be something more serious wrong

[ajay31]

step 1. disconnect battery again ( +ve side)
leave 5 mins
reconnect
then hit alarm fob button.
if this does not work.
lock car, unlock car,put key in ignition turn to position 2 and hit button.

good luck ajay

[charlE30]

Well the car batt's now fully charged and the fob isn't deactivating the alarm or the immobiliser (although I've disabled the siren for the neighbours !!)

I only found out be accident that it had a working alarm with remote central locking as when I bought the car I was told the fob is for the immobiliser. Turn to access 2 press the button and it'll start which it did, you'd hear a relay or something click so you'd know it had mobilised.

I now can't get in the car without the lights flashing even though the central locking is working perfectly, there's no click when you press the button at access 2 so it won't bl**dy start.

Does anyone have any ideas as I've just rebuilt the engine and can't fire her up

How easy is it to change the batt in the fob??

[dazleeds]

fob should come apart easily mate
either 1screw or just clips together but be carefull not to lose anything open very slowly then just pop a new batt in and hopefully youll be ok

[charlE30]

This is what it looks like
Sorry for the crap photo, camera phone!!
Can't see any screws, did wonder if I could pry it apart change batt then glue it back together??

[dazleeds]

not what i was expecting it to look like

still worth seeing if it does come apart but that looks very delicate so i,d be extra carefull with that

[Brianmoooore]

Never seen one of them, and never seen one that doesn't come apart.
Doesn't it have a LED that lights when you operate it?
If the metel ring is removable, I would take it off and try opening it from that corner.

[charlE30]

No LED, I'd never seen one like this before either that's why I had always assumed it was just an immobiliser fob?? I'll try gently to open it up

[charlE30]

Well I managed to pry it apart and there is an LED


There are two batteries one on top of the other (CR2025??) tagged to the bottom of the circuit board, Brianmoooore what would you recommend?

[A1BMW325iSport]

do a search on the net for the batteries, then buy some and solder them in.

you can get a new sticker for the front panel as well they are on ebay sometimes

Matt

[Brianmoooore]

Well I managed to pry it apart and there is an LED
There are two batteries one on top of the other (CR2025??) tagged to the bottom of the circuit board, Brianmoooore what would you recommend?

Change the batteries!!
These are 3V lithium cells, so stick a meter across them and see what you get.
They are available from www.cpc.co.uk in tagged or untagged versions.
If yours are tagged, then the ones you want are BTO1796 at 54p each, probably, or could be BTO2167 or 2168 at Ԛ£1-14 each.
Beware the small order carriage charge.
They also sell bylbs for OBCs, illuminated switches, batteries for SI boards, silicon grease,contact cleaner, and there is a whole automotive section.

[charlE30]

charlE30 wrote:
Well I managed to pry it apart and there is an LED
There are two batteries one on top of the other (CR2025??) tagged to the bottom of the circuit board, Brianmoooore what would you recommend?

That was a bit of a stupid question

Cheers for the info

[charlE30]

Well I've changed the battery and put it all back together. The LED flashes when you press the button and....... nothing. No alarm deactivation, no doors unlocking and in accesory 2 on the ignition.... nothing car is completely immobilised.

I've got a feeling that disconnecting the fob battery has lost it's code to talk to the car

I'm going to start a thread in chat to see if anyone else has the same fob, I'm hoping that there could be a simple sequence to re-code.... and someone knows it..

[herman]

Had one like that the only thing to do is get it ripped out and start again cheaper in the long run as I found out.

[Ant]

Find the alarm module first, not the siren there should be another unit buried in the car somewhere.

once you find it post up a pic, there should be a code switch( PTM) accessable through a small hole in the unit itself, power on, hold switch on unit in, press remote fob and release button, works on e36 etc...

iirc those alarms were provided by autowatch, the other type with the two buttons and the key fod corner "cut off" are made by serpi-star

HTh.. ish

[A1BMW325iSport]

i thought that type of alarm was sigma, at least thats what mine was and it had same remote as pics above

they were dealer fitted in the 90`s