Alarm retrofit issues

[MTBPhil]

Wondering if anyone can help

I got a siren off ebay to retrofit into my van (as it carries mountain bikes, bit of extra safety)
1K0951605C is the siren I got - and the bracket to mount it behind the wiper motors

Installed siren, got a loom made with the 3 wires
+12v I've added into the fuse box in position 24 with a 5amp fuse
Earth I've put to one of the loom earth points under the windscreen scuttle panel
the LIN wire I've added into the white BCM connector on Pin 36

I've gone into VCDS - 09 long coding, Byte 6 enabled Bit 5 "Anti-Theft-System installed/active" and disabled Bit 3 "Anti-Theft-System Simple Horn installed (North American Region Only)"

I also enabled the "Locking Confirmation via Horn active" as I'd like the locking chirp

Tested by locking van - no chirp
Went into the output tests and activated "Alarm Horn (H12)" - nothing just says "not installed"
Also now got a fault code 01134 - Alarm Horn H12 004 - No Signal/Communication.

I also noticed all the guides/videos I watched that in the 09 module under Extra it should say "1K0951605D LIN BACKUP HO" - mine does not, it just says "Geraet 08192"

Is it most likely that the ebay alarm siren I bought is dead? or have I missed something out?
Thanks

[Doc]

Have you checked for battery voltage and GND at the siren plug?

[tommyzooom]

Info on coding here...
https://www.youtube.com/watch?v=hlZvWzDTpyI

[C Chis]

If your van is like mine, a pre facelift one then I thought you’d have a CECM not BCM. If you’ve a CECM (8 sockets on top not 3) I think the alarm horn wire should go into T6/6 (plug J) on the convenience system central control unit (J393)

This is a common connection for the alarm system including the interior monitor and inclination sensor

Like yourself I’m looking at retrofitting the alarm system including the interior/inclination sensors and switches, etc.


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[MTBPhil]

Have you checked for battery voltage and GND at the siren plug?

I checked voltage at the back of the new fuse I added and it's got permanent +12v
Earth is going directly to an earthing point on the chassis.

I haven't checked at the actual plug yet because sadly I'd put all the scuttle panel and windscreen wiper motor back together... Going to have to dig back in there to check at the plug - but the loom is brand new so it should be fine.

[NZDubNurd]

There is a REALLY good chance the alarm siren is dead - they are fairly common to die after the internal battery leaks and dissolves the board.

I repaired mine in my 2006 Touran, but it lasted about 3 months and died again - the board was quite badly damaged anyway.

[MTBPhil]

Yeah I saw a lot of posts about the internal battery dying after 8-10 years - and this alarm is probably 11 years old from a scrap yard
I'll probably chance £60 on one of the "new" ones from china - but if it warms up I'll take this one back out, check continuity at the connector and maybe crack it open to see if it has destroyed the board

Thanks

[MTBPhil]

Thought I'd close this off in case anyone else has similar issues

Considered getting another alarm 2nd hand but as the batteries seem to die after 8 years or so - didn't seem worth it
Was going to buy one of the new ones off of a "popular chinese site" but read loads of people saying they just didn't work on arrival

So bit the bullet and bought a brand new alarm siren from VW - turned up today, plugged in, worked first time

I'll take my old one apart at some point and see if it looks like it's saveable with a new battery but I'm gonna guess it's leaked onto the board like all the others. Thanks for the advice

[schizzo]

Could you tell me where the H12 siren is located in caddy 4?
I can't find any news about it online
thanks