Why does an alarm siren have to be coded to a vehicle?

[kolobos]

I need a new alarm siren at £85 but also have to pay for it to be coded to the car, why? The siren fits many other cars so why does it need this, just puzzled.

Steve...

 

[Dec]

I fitted my alarm siren without the need for “coding”, do you know what siren you need?
Can you not fit it yourself and see what happens?

Dec

 

[zenman63]

So your fitting all MB parts, harness tilt sensor and siren, motion sensors?
If so it does need coding

 

[horgantrevor]

As dec has said if you are only replacing siren then no coding required

 

[thejohn]

+1 for no coding fitted a new siren just last week no issues

 

[AndyPCD]

The only thing that usually happens if its not coded is the alarm will chirp when locking and unlocking the vehicle.

 

[Dec]

Mine chirps on locking and unlocking, it was self fitted.
Is the chirping turned off because it is now regarded as a noise nuisance?

Dec

 

[whitenemesis]

Mine chirps on locking and unlocking, it was self fitted.
Is the chirping turned off because it is now regarded as a noise nuisance?

Dec

Yes, that's my understanding.

 

[kolobos]

I had a new siren fitted today, it was the newer version that chirps when it is armed or disarmed. It also had to be coded so I could not fit myself which I am more than capable of doing.

I rang a genuine dealer to buy the siren and they said it must be coded to the vehicle.
I rang a local Mercedes specialist who also said the same thing! Well it's fitted and working and all error codes deleted that were created due to the faulty siren and actually the knackered car battery that I also replaced a week earlier. It cost £175 and all is ok at present.

Thanks for the replies.

Regards,
Steve...

 

[Dec]

Thanks for the feedback Steve.

Dec