My alarm backup battery located on the firewall hasn’t worked for a while, so as I’ve finished work for Christmas, I thought I’d remove it and check the part number for ordering a new one.

The part number is “6G9N 19G229 DE”, but I can’t find anybody selling new ones, only used ones on eBay which I’m not interested in.

Does anybody know where I can purchase a NEW replacement from, my car is a 2006 4.2 XK?

 

Are you talking about the whole alarm unit. The battery is inside and not a FRU.

The siren unit is the same as Ford Fiesta which you can get new at a reasonable cost. I got a new one off EBay a couple of years ago.

 

How did you learn the battery had failed?
Thanks,

 

In the UK the siren and beep /double beep which uses the Sounder is programmed OFF. So generally you don’t get a sound when locking the car.
I knew my battery had failed as I was getting a Geiger counter sound at various times even when the car was locked.
This sounder unit is permanently connected and can flatten the main battery if faulty.

In other countries the sounder is programmed ON

 

My main battery in the boot started discharging over the course of a week and by checking fuses with an ammeter and removing them, I narrowed it down to the alarm sounder backup battery. When I removed the backup, I prized it open and found it full of water and totally corroded.

 

I’ve been getting the Geiger counter sound too.

 

Yes, I've had that "beep" turned off. Flashing lights do me fine. But I was under the impression that the alarm was powered by the car battery??

 

Alarm runs off the main car battery, but if a thief disconnects it, the battery (green in pic) in the sounder takes over - this is the state of mine!

 

Congrats on finding the problem!!!!

 

Somewhere above it was mentioned as “firewall”.

Can anyone show specifically where in the car I can find this?

 

On a RHD car. It’s on the firewall under the RH bonnet release unit.
You have to move the explosive Device to get to the holding bracket.
Its a bit fiddly but very doable with a bendy socket set.

I assume on a LHD car it’s on the left side but could be wrong

A more detailed explanation with pictures is on here so worth search on Sounder

 

As per the photos above, mine was in a similar mess - just get a used sounder from another Jag and use that - forget wasting your time trying to replace the battery - no you dont need to program it

 

As I said above get a Ford Fiesta (UK name )one as it’s a lot cheaper and exactly the same unit.

 

You don't need a new one, I got a used one there's plenty for sale just get one from a newer Jag like I already said

 

Seems like a lot of effort to replace a battery that will power the alarm... for an insignificant period of time, should the car battery be disconnected.

 

To replace the sounder in my XK it's around an hour, maybe a bit more as it's a bit of a faff due to no room in the firewall area. The sounder makes a distinctive beep when armed, and obviously sounds if the vehicle is intruded upon or jacked up so worthwhile replacing. It's not worth repairing the old unit, they aren't expensive and they are used in many vehicles including Volvo so you don't need to think this is a unique Jaguar part, like most of the parts on a Jaguar they are made to accommodate many vehicles just as the fuel pressure sensor and lot's of more parts.
The only thing to be mindful of is the holding bracket needs to have the screws in the correct place, so I got a used one from a different Jag no idea what model it was but it wasn't a XK and it fitted fine

 

Well, too much effort for me.

Merry Christmas!

 

I did this so learn from my fail make sure battery is disconnected before removing the bonnet air bag otherwise you get permanent error on the dash because it believes the air bag deployed. If this does occur you can get the bypass units of ebay and solder them in to make the circuit to remove the dash light else it would be MOT failure or expensive trip to dealership

 

I done mine without disconnecting anything, however if you have large hands forget it - my hands are small enough and at that I remember it was incredibly difficult to get the sounder connected up without actually moving the airbag out of the way - I think I shuffled it sideways, the airbag which gave me a window to connect the sounder

 

I just pulled mine and disconnected the whole thing...

Really no purpose,,,,