W202 - How to test car alarm?

[Cw-kid]

Hi

Not sure if the factory fitted alarm is working properly on my car?

I had it jacked up yesterday to Waxoyl under the wheel arches and as I was jacking up the car all the indicator lights started flashing, which is the towing alarm thing, but no alarm sound / siren could be heard.

What's the best way to test it is working properly?

There is this button on the dash board, but I never really knew if the alarm was turned on or off?

Many Thanks

 

[Dec]

The light will flash as illustrated below when the alarm is armed.
Locking the car with the remote arms the alarm…alarm light will flash.
Unlocking the car with the remote disarms the alarm…alarm light will NOT flash.

To test;
Open driver’s window.
Lock car with remote.
Wait 1 minute for alarm to set properly.
Reach in through the open window and open door/s and or bonnet.
Siren should sound for abut 30 seconds and hazards should flash for about 3 minutes.

Dec

 

[Cw-kid]

Dec

Thanks will test it and report back.

Cheers

 

[Cw-kid]

Hi

When the car is locked the Red light flashes, when the car is unlocked the Red light goes out.

I opened the drivers window, then locked the car again, waited a moment and then opened the drivers door, the indicator lights started flashing but no sound / siren can be heard. So appears that is not working for some reason?

Thanks

 

[Dec]

You have a faulty siren then if there was no sound from the alarm siren when it was triggered.
You need a replacement siren.
The probable reason, see here… Alarm / Siren Issues : Goes off for no reason/Kills Battery FIX DIY.. - MBWorld.org Forums

Dec

 

[Cw-kid]

OK thanks, I will look in to it and hope a replacement is not too much cash.

 

[Dec]

About £100 from MB dealer.


Dec

 

[Cw-kid]

About £100 from MB dealer.


Dec

Might have to live without it then. Or maybe I can find a tested second hand one cheaper. Can't say I'm keen to spend 100 quid to fix it.

Will try and take it apart and have a look at least and maybe I can just change the internal battery or something to fix it myself.

 

[Cw-kid]

The attached images show the location of the siren and removal / installation details. Wish I'd known that yesterday I could have took it off whilst I had the wheels off the car.

Can't see any used sirens for the W202 on eBay currently. I assume I can get the part number I need off the siren unit I remove.

Cheers

 

[Dec]

You could leave it as it is if there are no more false alarms but it may get worse and start flashing the hazards lights during the night and flatten the car battery.
Or you can just unplug it and replace it sometime in the future. When you unplug it, it might go off, powered by its own internal batteries, so best to remove it from the car, protect the alarm plug from damp/wet as it will remain live all the time.

My car W202 is September 1997, in picture I removed A 220 820 28 26 a while back and replaced with A 219 820 32 26 from MB dealer. A 220 820 28 26 no longer available and is replaced with A 219 820 32 26
The problem with a second hand siren is that it might be in the same condition as the one you already have, the usually last about 7 to 10 years before the start giving the trouble that you are experiencing.

Without a working alarm you have no theft cover on your insurance.

Dec

 

[Cw-kid]

"Without a working alarm you have no theft cover on your insurance."

I assume the alarm and more importantly the engine immobiliser are still working without the siren functioning.

But I'll ring Merc tomorrow and confirm the part number and price as I need to call them about some other parts as well.

Thanks for the good advice!

Cheers

 

[Cw-kid]

Dec

With that new Siren unit, do you get an audible beep notification when locking / unlocking the car? Or does it have to be programmed / turned on with a Star machine, or is not an option on the W202 etc.

Just saw a few forum threads where people were saying they had fitted a new siren to their Mercedes and then this new feature started to occur.

Thanks

 

[Cw-kid]

Just saw this in another thread

"If it helps, the EPC for my car, a W202 C43, gave part number A 220 820 28 26. However, this proved impossible to source.

In my googling, I came across the advice that "A 220 820 28 26 goes to A 203 820 38 26 then on to A 171 820 25 26 and ends up at A 219 820 32 26. All do the same job and fit in the same place". Notice the above includes your W208 part.

This being the case, I went to Inchcape, who confirmed that the correct part to order now for my car was A 219 820 32 26 (£97.92) - even though I could find no trace of the changes in EPC. Anyroad, I bought the siren and it fitted fine. So it looks like the advice above is sound.

Might help you to source one on eBay. Good luck!"

So seems there are several part numbers that should work, I've just seen a new one (A2198203226) on an eBay auction so will bid on that I think.

 

[Dec]

Immobiliser and locking works fine with the siren disconnected but no flashing hazards on locking/unlocking as far as I remember.

A new siren has the beeps turned ON by default and can only be turned OFF with STAR.
If you go to a main dealer he might tell you that it needs to be programmed on star, which is true, in a way as the will turn off the beeps that sound when you lock (3 beep) and unlock (1 beep) for this to happen the will charge you an extra amount and will want to fit the siren for you so it might be , say £150?

You can just buy the siren based on your VIN number and fit it yourself, it may or may not be the same part numbers as in my pictures a we don’t know the year of your car.
When you fit the siren yourself (make sure the car is unlocked when removing and fitting the siren) you won’t have access to STAR diagnostics to program the beeps from the siren so the siren will beep on locking/unlocking.

The reason for the turning off of the siren locking beeps is unclear, some say it’s considered a noise nuisance and has to be turned off under some vague EU law, I think perhaps it could be a racket/excuse to extract more money and labour charges by the dealers.

Either way, I fitted my own siren a couple of years ago, it beeps on locking/unlocking… the are not at all unpleasant or loud beep. I’m now considered an Outlaw so if you fit your own siren you will be an Outlaw too.

Dec

 

[Cw-kid]

Dec

I thinking having the beeps notification would be a good feature to have when locking / unlocking the car, as long as its not too loud. My car is a V reg which is Jan 2000.

Hope I win that auction for a new siren I've just seen, at a good price, or I will just keep an eye out for a bargain on eBay. The siren probably hasn't worked for years anyway's and I just never noticed it until now.

Many thanks

 

[Dec]

A2198203226 is what I have fitted to my car, buying used is risky, unless it’s very cheap then it might be worth a chance. Age is every thing, if its 10 years old then its probably nearly knackered.

Dec

 

[Twistedmind]

Don't buy a second hand siren. They are sealed units and you cannot see the condition of the PCB. Or battery

These units always fail with time. The battery leaks acid on to the PCB and makes it U/S

I got a new one from merc for 80 quid. There is an optional wiring harness upgrade too.

Sent from my iPhone using MBClub UK

 

[Cw-kid]

'A2198203226 is what I have fitted to my car, buying used is risky, unless it’s very cheap then it might be worth a chance. Age is every thing, if its 10 years old then its probably nearly knackered.'

Yeah I agree, for a tenner or so its worth a gamble, any more and its not worth the risk with a used unit. Hopefully I'll win this new one which the auction ends tomorrow.

I've neglected my car for the last few years, its always been serviced properly however, but I have a list of things not working, one of which is the Air-Con which I think must have a leak and needs re-gas. I've just had some rust repairs done on two doors and a new front bumper (top half) as someone damaged it, so sprucing up the old girl, with new Carbon fibre effect door pillars and dark smoked front indicators lenses and new number plates etc.

Just had it serviced again and new auxiliary belts fitted, so spent quite a lot on it recently. Next job is to re-spray the 5 spoke alloys, might have a go at that myself in the summer. Also bought some of those black carbon fibre look centre caps for the wheels, which look better than I thought they would do, but the car is also black. Been looking at Avantgarde grills for the W202 which look neat also.

108,000K on the clock and I hope it runs for a good few years yet!

 

[Cw-kid]

There is an optional wiring harness upgrade too.

Hi

What is that for / do ?

Thanks

 

[Dec]

If you got a year out of it then £10 would be alright, it might not beep though.

Dec