C220 Alarm & Imobbiliser

[mercedesc220]

Hi Guys,

Does anyone know if you can switch off the factory alarm & Imobbliser?

Its just that the alarm keep tripping itself and i have to keep disconnecting the battery and then wait for 5 minutes and then re-connect it.

My dad uses the car most days and he is fining it very difficult to cope with.

thanks

 

[landover]

What year is your car?????

 

[mercedesc220]

1996 N Reg.

Its got the red & green lights on the door and on the interior rear view mirror.

 

[jberks]

Are you sure its a factory alarm ? Mine had the lights and remote locking, but no alarm. I had one fitted when I bought it and you can't tell the difference.
I'd look for the siren. Many had a key lock on top to disable them, but then you'll need the key.

 

[beckham7]

must be an aftermarket alarm mate
mines a 1995 n plate and it has an aftermarket alarm my sirens under the drivers side bonnet near windscreen
disconnect the alarm :lol:
on mine i switched the 2 plugs over on the siren

 

[mercedesc220]

Mine is activated with the original key fob for the car which also does the central locking and has the ignition key folded into it.

There is a siren on the passengers side under the bonnet with a key slot on it but i dont have the key.

Will disableing the alarm also disable the immobiliser?

 

[jberks]

It could do. There are alarms that will activate based on the cars original remote central locking, rather than its own remote. This is what I had on mine so you couldn't tell the difference between that and a factory fitted one, it all worked off the Merc key/remote. It's possible that yours is the same. I'm not sure whether the immobiliser is part of the car's original circuitry or the alarm. If it is the alarm and if you don't have the key, unplugging it may well invoke the immobiliser. Many are a simple relay wired into the fuel pump circuit so unless the alarm shorts the curcuit, the pump won't run. You may need to short these wires before the car will run.

 

[500sl]

So you still don't know anymore.

[/

 

[mercedesc220]

I am just so confussed............. :roll:

Dont want to take it to Merc as they will charge an arm and a leg..

 

[190D]

there is someone on this forum called numbnuts he is inside for stealing cars may be he knows how to bypass the alarm.

 

[landover]

1996 N Reg.

Its got the red & green lights on the door and on the interior rear view mirror.

Are the both lights working on the mirror????

 

[mercedesc220]

Yes both lights are working on the mirror and on the handle.

 

[landover]

That's strange the problems start on this system when there is a bulb falure. Try new batteries in remotes.If the signal is misread that can be a problem.

 

[piestore]

IFZ

hi

SOUNDS LIKE YOU NEED A NEW ifz CONTROL UNIT

 

[jberks]

I think we're off the point a bit. The problem is not setting the alarm as I understand it, it's just that it's going off a lot.
I would firstly check whether there is a three pointed star anywhere on the alarm as it could easily be a faulty or over sensitive after market unit.
If it's an after market unit, it's easy enough to replace and any reputable auto electrician will sort it if you aren't comfortable with these things. That said, even if it's a factory unit, it can probably be swapped for an after market one and they are pretty much interchangeable.
One final anecdotal thought,
I used to have an alarm problem where it went off a lot in the winter - usually 2-3 mins after I had left the car. After a lot of hassle, it dawned on me that the problem was heat rising out of the footwell heater vents. I opened the door and cold air rushed in. I closed the door and the heat difference between the air in the car and the vents, caused convection and triggered the alarm. I ran cold air through the vents for a few secs, closed the footewell vents, and it stopped happening.

 

[mercedesc220]

Prople i think i have found the solution.

Recently I have changed they battries in the key fob and 2 weeks later when i went to open the car it tripped the alarm.

I changed the batteries again and it worked fine, 1 week later the same happened again.

I have come to the conclusion that the Key fob is faulty.

Any views?

 

[sedstevo]

mercedesc220, did you resolve your key problem. I would be interested to know.

Regards

 

[anyweb]

did you try synching the key again after changing the batteries ?

if not it will be out of sync with the car and cause those dam red/green lights to misbehave,

for some reason mine mis-behaves all the time, so much so that i'm used to it now.


don't you have the other key ? test that one instead and see do you have the same problem, or try re-syncing the fob by getting in the car, pressing it so the RED led comes on, then press it again so the GREEN led comes on, then insert the key into the ignition and turn to position 2 within thirty seconds

that is 'supposed' to re-sync, but i dont think it's working on my car....

cheers

anyweb

 

[sedstevo]

Anyweb, I'd be interested to know what happens when yours "mis-behaves all the time".

My '96 C200 is giving me grief with starting at the moment. Suggestions are that the transponders going in the flip key.


I have tried re-syncing like you have done, but I dodn't think it makes any difference.

BTW - your page on Brake Pad changing is very useful.


Regards

 

[jberks]

Transponders don't generally fail - the button is a weak point but other than that they pretty much keep working. We had one declared as faulty. Reset the system, replaced all the batteries and resyncd - now all 3 work fine again.
Sometimes the system needs clearing down (not sure how the dealer does this) but a resync hasn't failed yet.