2003 S211 alarm siren going off!!

[ksareen]

Hello, My 53 reg E220 CDI ESTATE suddenly has the alarm going off.
Remote key fob ON/ OFF does not make any difference.
Car running or not does not make any difference.

Its random, loud and persistent.

Questions:
1. Its coming from O/S front fender. Can I remove the driver side front wheel, plastic trim and take it out? Is plastic trim easy to remove or fiddly?
2. Can the alarm siren be repaired or is it a quick buy and replace job? Would it need to go on STAR after a new one is installed?
3. Once removed, would the locking work as normal with the remote (lights/ auto-fold mirrors etc)?
4. Lastly, would this drain the main battery if deferred? I understand it has its own built in batteries, so would it not just run out of its own power eventually?
But if removal is easy, I would rather remove it to get rid of this annoyance.

Early advice on removal would be highly appreciated.
Thanks in advance..

 

[joecash]

there is a thread on here that gives lots of info - cant remember which though - I'm sure someone with a better memory than mine will point you in the right direction

 

[Druk]

You need a new siren. Common fault caused by its internal battery leaking ooze onto the PCB. Not fixable. Removing wheelarch liner gives access. It can be unplugged till you get a new one but it's not worth the bother taking the liner out twice.

 

[ksareen]

Can you please recommend where to buy the new siren? I guess MB main dealer would be expensive.
Would disconnecting the main battery turn it off as well (for the night)?

If someone could provide the part number, it would be great.
Thanks.

 

[BlackC55]

Only get one from MB main dealer.

 

[Vilus]

As above. They cost about £65 + Vat. The siren unit is fixed to a metal bracket which is secured with security torx bolts. You will need the correct bit to remove it, or else a sharp tap with a drift and hammer to snap the centre pin, then you can use a standard Torx bit.

If you disconnect it your insurance cover could be invalidated with no active alarm?

 

[ksareen]

Is any programming required (Star diagnostic etc) once the new one goes in?

 

[BlackC55]

No

 

[ksareen]

The local MB dealer does not have it in stock for today!! Would take 3 days if I ordered one.

Hope removing the wheelarch is not a tough job as I intend to disconnect it for the moment. Any pointers would be welcome here.

Thanks to all for your help.

 

[Dec]

This is a W203…http://www.mbclub.co.uk/forums/electronics/86238-indicators-fast-flashing-no-apparent-reason.html

Don’t know which side it’s on on your car.

Dec

 

[ksareen]

Thanks Dec for pointing to this post. I am sure it will help.
I am thinking about the fuse. Does the alarm sounder come with a fuse (2003 S211 E220 CDI Estate), which can be taken out so the siren is disconnected (until I get a new one)?

 

[Druk]

I watched mine being done. iirc I was told there is a cableplug into the alarm unit which you can pull and it stops the noise. No detriment to car.

 

[ksareen]

We need someone to highlight that plug to us mate so I can do that. I can't find the fuse information online either:-(

 

[Dec]

A W202 has an alarm fuse, if you have one then you can try removing it, however I believe that the siren gets a live feed all the time, whether car is locked or unlocked so as to keep the backup batteries toped up.

If the siren is disconnected, either by unplugging the siren plug or disconnecting the car battery then the alarm is supposed to trigger, however you seem to have a defective siren so no way of knowing what will happen.

Not unplugging the siren, as it is defective, could drain the battery… that doesn’t mean that it will, the only sure way is to unplug the siren.

Is your central locking working ok?

Plug should looks like my W202 plug below.

Dec

 

[Major774]

The local MB dealer does not have it in stock for today!! Would take 3 days if I ordered one.

Hope removing the wheelarch is not a tough job as I intend to disconnect it for the moment. Any pointers would be welcome here.

Thanks to all for your help.

It only takes me a couple of minutes to remove the wheel arch cover not hard at all.

 

[ksareen]

Yes, my central locking works mostly OK, apart from driver door that does not lock sometimes. The locking sounds like AK47, but that's another concern I think.

The blinkers are going off in my car as well now.

I was going to disconnect the siren now but its too dark,will do it tomorrow in my lunch break and get back.

Thanks for your help.

 

[Dec]

Is it going off randomly while the car is locked or does it only go off when you try to lock it?

Dec

 

[Dec]

You have the de bumpsie door lock?

Dec
[YOUTUBE]wKMBWS5tpBc[/YOUTUBE]

 

[ksareen]

HI Dec,
The siren and hazards are going on randomly. Several attempts of luck and unlock can stop it before it starts again. I hope the battery won't get flat through the night, also hope not to annoy the neighbours.

That video exactly describes my locking situation. It sounds similar and takes several attempts to lock the car sometimes.

Does that toothpick hold itself or does it eventually fall in? Would you recommend that I try that?

Thanks once again.

 

[Dec]

Yes if it will work for you, you could use several turns of Sellotape on the top end of the stick so it can never slipe through the gap.
Putting the key in the ignition should disarm the alarm.

Dec