Alarm siren query

Crikeymikey

Crikeymikey

A2OC Donor
Assuming the alarm siren is functional, is it supposed to "chirp" when the car is locked when using the remote?
I ask because I have just connected a siren that I know to be working (it's off my 2002 Mk1 TT) and the A2 still doesn't chirp.
The indicators have always flashed to give the visual confirmation and I put the absence of an audible confirmation from the siren as a sign that the ancient back up battery had leaked and eaten the pcb, which did happen to my TT years ago.
Thanks in advance. :)
 
Afternoon,

The audible alarm chirp upon locking the vehicle has probably not been coded into the CCCU.

If you have access to VCDS then you can very quickly enable this feature. Plenty of information on these pages which explains the specific coding figures.

I’ll look for a helpful link for you shortly, but first confirm you have access to VCDS.

Kind regards,

Tom
 
Crikeymikey said:
Thanks for that. I'll do a scan with my OBD11 Pro and see if I can access the CCM. I have a replacement siren on the way as well. Just another feature to tick off the list. Much obliged. :)
Click to expand...
First, if you haven't already, check if the siren works when the alarm is triggered for real. The actual sounder is a common failure on older VAG cars.
Mac.
 
PlasticMac said:
First, if you haven't already, check if the siren works when the alarm is triggered for real. The actual sounder is a common failure on older VAG cars.
Mac.
Click to expand...
You're right about that, Mac. The TT's siren gave up the ghost (several years ago) without my noticing. Too late to prevent the damage to the pcb from the battery leak so I bought a used replacement (which was several years old), checked that it worked and then immediately soldered a new battery in.
The A2's siren definitely doesn't work, and I imagine it's the original so it's certain that battery and pcb are toast. I'll check the replacement when it arrrives and then solder a new battery in it. It'll be good for another 10 years. None of this necessarily improves the ownership experience but it's one kore thing ofnthe list of niggles.
My OBD Eleven will allow me to recode the CCM for the chirp. Hurrah!
 
PlasticMac said:
Can the A2 siren be taken out, without removal of the driver's side boot trim?
Mac.
Click to expand...
I couldn't see as it is tucked away under the fuel filler cap solenoid and you have to go by feel. The connector can be removed, with a pick. I was able to connect the siren from the TT to do the functional test. There are a few inches of cable to play with so I intend connecting the replacement siren and then rigging up a new fixing point in a more convenient spot behind the tail light, leaving the original in place for now. He says!
There is a slim chance that the replacement siren (which is a later "C" variant but still the most common VAG siren) may not be compatible with the CANBUS. When I replaced the TT's years ago I was told the sirens look the same (apart from the crappy original) but the message set to the CANBUS can vary. Had no issue with the TT so I'm keeping my fingers crossed for the A2.
I'll keep you posted, Mac. :)
 
Success!

This update is mostly for PlasticMac's benefit but others may be interested.

Received a used replacement siren, 8L0 951 605A, same as the one fitted it to my Mk1 TT. My TT is 2002 vintage so the CANBUS protocol is the same as my A2. Checked it actually worked by briefly connecting to the TT. This can also be done by carrying out an Output Test on your A2 if you have a competent scan tool. You may also have to clear a confort module fault code from the original siren failure.

The afore mentioned part number is not my TT's original incidentally, but an updated one that was fitted to later Mk1s. I fitted it years ago after the original gave up. Do not try later part numbers as they won't work, even though they will look the same. The protocol is different on later sirens.

Removal of the old alarm siren, without pulling trim off, is not possible. There's literally a 1mm clearance deficit, so I have left it in place and mounted the replacement alarm on the soundproofing foam with double backed adhesive pads after making a hole in the foam to locate the siren's mounting stud. In the long term I will mount it in place of the original, and fit a new battery while I'm at it.

20220519_090536.jpg

20220519_090536.jpg


If someone following this procedure knows their A2 used to give the audible single beep originally, then there is nothing more to do. Their A2 should now beep as previously, i.e. before their siren packed up. Equally, the siren should now activate when the alarm is triggered.

In my case, I now locked the car to listen for a beep when the indicators flashed. No beep meant my A2's Comfort Control Module had never been coded for the siren beep in the first place. I have an ODBeleven Pro already (15 years of Mk1 TT ownership will teach you many things!) so I was able to code the function into the CCM, by adding 01024 to the existing value and carrying out an Output Test.

Screenshot_20220519-092156_OBDeleven.jpg

So, for the price of a used part (£25) I now have a functioning alarm siren for deterent purposes AND the audible acknowledgement, on remote locking, that the alarm is armed. This may all sound like a bit of a faff but is actually quite straight forward and piece of mind is a wonderful thing for £25.

The foot note here is this. If you have a functioning siren still, it WILL fail soon. The back up battery will fail and leak, causing irrepairable damage to the PCB. If you do not have a functioning siren it is because this has already happened. New sirens (8L0 951 605A) are available on ebay for around £140 plus customs duty (somone in Latvia has bought the stock). If you have basic practical competence, my advice is to buy a used one that is still working and, at the earliest opportunity, open it up and fit new batteries.
 
Crikeymikey said:
Assuming the alarm siren is functional, is it supposed to "chirp" when the car is locked when using the remote?
I ask because I have just connected a siren that I know to be working (it's off my 2002 Mk1 TT) and the A2 still doesn't chirp.
The indicators have always flashed to give the visual confirmation and I put the absence of an audible confirmation from the siren as a sign that the ancient back up battery had leaked and eaten the pcb, which did happen to my TT years ago.
Thanks in advance. :)
Click to expand...

Thought I'd reply to the original question. Do you refer to the horn beep akin to American cars when they are locked?
If so, to the best of my knowledge that is not coded in on European cars as it is technically illegal to sound the horn without due cause, and locking the car does not count as such (or beeping the horn when you drive by someone you recognise, or leave/arrive somewhere). Not saying you should be worried about it though, as I have never heard of someone actually getting a fine for doing this.
 
BearMcPear said:
Thought I'd reply to the original question. Do you refer to the horn beep akin to American cars when they are locked?
If so, to the best of my knowledge that is not coded in on European cars as it is technically illegal to sound the horn without due cause, and locking the car does not count as such (or beeping the horn when you drive by someone you recognise, or leave/arrive somewhere). Not saying you should be worried about it though, as I have never heard of someone actually getting a fine for doing this.
Click to expand...
It's not the horn (as in "excuse me, could you possibly move please?"
It's the alarm "siren" (which Audi refer to as the horn). The beep is more a quiet cheep. No nuisance factor at all, even in dead of night, although I haven't actually tried locking the car after midnight.
Mac.
 
You must log in or register to reply here.
Back
Top