Retrofit Alarm Siren

[Jsstelt]

Small howto for retrofitting a alarm siren. 

You can use the alarm siren to enable the alarm option in the BCM. When the car is opened from the inside the alarm goes off. 

And you can use ATA confirm. When opening and locking the car a beeb is sound. 

This is pretty much an easy fit. 

You need 2 parts. The Alarm Siren and a cable. 

 

I ordered this alarm horn:

1K0951605C

 

I think every siren that looks like this one will work. Most VW Skoda and Audi sirens are the same. 

Bought this for $25,- on eBay. 

 

Then you need this cable:

1J0973703

 

bought on Ali express for around $15,-

https://m.nl.aliexpress.com/item/32840042101.html

 

I placed the siren under the hood. And the cable runs the same route as the hose for the rear wiper. 

 

The harness cable has 3 wires. Red for 12V constant power. 

Brown for ground. (I connected this somewhere under the hood. There are more places you can connect this, as there are more brown ground cable connected to the chassis). 

And there is a blue cable which connect to pin 36 on connector B (white) in the BCM. 

 

After that use VCDS and go to 09 central electronics. 

 

Check byte 6 bit 5

and uncheck Byte 6 bit 3 (else the car horn will sound when the alarm goes off and not the siren).

 

 

Check Byte 5 bit 1 and bit 4 if you want to hear the beep when locking and unlocking the car. 

Uncheck bit 2 and you can enable / disable the ATA in your MFA. 

You need to check bit 1 and 4 first. Else you can enable ATA in mfa but it won’t work.