Alarm keeps going off when driving, A170 CDi Auto

[blue.midget]

Can anyone help? I have an A170 cdi auto, 51 plate, W168 and the alarm has started going off after I have driven a 10/20 metres or so, the only way to stop this is to switch the car off, take the key out of the ignition and then press to "open" car. Start car back up again, apologise to other traffic and drive on. I am starting to become a nervous wreck. Anyone know what the problem is or if it is possible to disconnect the alarm completely?

 

[blue.midget]

I should add that I am usually accelerating when the alarm goes off. It does not coincide with the car auto locking the doors, and the battery is fine in the key(s). I have two keys and the problem occurs when either is used. I have also tried the button in the car that relates to the car being towed. This appears to make no diff either.

 

[Dec]

Locate and unplug the siren, not sure if this here .. http://www.aclassinfo.co.uk/mypage.51.htm ... is the same set up as yours, let us know how you get on.

Dec

 

[blue.midget]

Thanks for the info, siren now disconnected, so won't scare the living daylights out of the wife when she is driving it!

Any ideas on how to stop the hazards from flashing when the alarm activates?

Cheers
Steve

 

[Dec]

As the hazards are flashing then there is another “box” somewhere as pictured below, I don’t know where it is located in your car but disconnecting/unplugging it will disable the whole alarm system.
Also, removing the right fuse might do the trick as well but I have no idea if there is a fuse for that alarm in the fuse box.

If you have a “dongle” type key, as in my link above, then you may be able to bypass the alarm system if you can find a place to plug it into.

Replacing the alarm siren may or may not bring the alarm system back into working order, you would need to contact the manufacturer of the alarm to obtain a siren, I think you might have a Scorpion alarm fitted but you would need to identify any part numbers on the siren and on the back of “box” I mentioned above.
Scorpion alarms… http://www.scorpionauto.com/stafftechnical.htm

Dec
Picture source… http://www.aclassinfo.co.uk/mypage.51.htm

 

[michael8664]

My 2001 A160 had the same symptoms.
The Scorpion siren batteries were dying so I disconnected and removed it, I was going to replace the batteries but haven't got around to doing it.
I still occasionally get the hazard warning lights going off shortly after starting the car.
I'm coming to the conclusion that sometimes I'm pressing the lock or unlock buttons on the keyfob while I'm turning the key in the ignition.
As you say, pulling over, taking the key out, and pressing the unlock button sorts it out.
Incidently, I've also put black gaffer tape over the sensors in the top corners of the windscreen.