Alarm malfunction – No audible single beep when double locking

RPSN

RPSN

New member
I’ve recently noticed that when I double lock the car, the audible single beep doesn’t always work? The hazard warning lamps flash twice (with a long second flash) which confirms the car is double locked. I’ve checked the instrument panel display ‘Vehicle Settings / Security Features’ to ensure that ‘Audible Lock Warning’ is ticked, which it is.

Done a few tests to see if the alarm is protecting the car which included.....

1. Leaving the driver’s door window open, double locking then waiting for just over 30 seconds before putting my arm in through the window space (it takes approximately 30 seconds after the alarm is armed, for the sensor to create a profile of the cabin and be fully armed).

2. Sitting inside the car whilst my missus double locked it from outside, waited for just over 30 seconds before starting to move my body.

The alarm was triggered in both these tests.

The further tests I did included......

3. Double locking then waiting for just over 30 seconds before shaking the car vigorously from outside and giving the tyre a few thumps with a rubber mallet.

4. Double locking then jacking the car up on the front UK near (passenger) side.

The last two tests (3 & 4) did not trigger the alarm.

I’ve checked the battery back-up security sounder (located in the rear right corner of the engine compartment and attached to a bracket on the bulkhead panel) by leaving the bonnet open then double locking the car. Two audible beep warnings are heard which is correct. The battery back-up sounder also incorporates a tilt sensor. The Central Junction Box (CJB) monitors the tilt sensor and can detect if the vehicle is being moved, towed or raised, and activate the alarm system.

If the security systems detect a fault with one of the security sensors, an error tone will sound from the alarm after the vehicle is unlocked and disarmed. I am sometimes hearing this error tone (2 audible beeps).

On the instrument panel display, I’ve checked ‘Vehicle Information’ and under ‘Last Alarm’ it says ‘Volumetric Sensor’. The Volumetric Sensor is located in the overhead console and it detects movement inside the cabin.

My thoughts are that the battery back-up security sounder (with tilt sensor) could be faulty and needs replacing? I doubt that a main battery reboot would cure this problem?

Has anyone experienced the same/similar issue with their car (no audible single beep when double locking) and if so, how did they rectify it?

TIA
 
‘Transport Mode’ is only available for customers that have an active InControl Secure subscription.....I don’t require this.
 
The only time I've noticed the absence of a beep is when I don't do the handle double press correctly. Opening and relocking the door has always fixed this for me. I think I've read that the battery on the sounder is good for 5 years, so maybe your faulty sounder battery theory is along the right lines.
 
The battery back-up security sounder is connected to a permanent battery supply from the Central Junction Box (CJB). An integral, rechargeable battery powers the sounder if the battery power supply from the CJB is interrupted.

I don’t think the issue lies with the sounder’s rechargeable battery? As I mentioned earlier, I’ve checked the sounder by leaving the bonnet open then double locking the car. Two loud audible beep warnings are heard, which is correct.

As the sounder also incorporates a 'Tilt Sensor' (which didn't trigger the alarm when I tested it), I'm thinking this could be the problem?

Before changing it, I think I'll get a diagnostic done at my local Indie to see if anything shows up?
 
My alarm sounder needed replacing recently. It started misbehaving by going off at anti social hours, and Beeping when I unlocked it!

Diagnosis was water pooling in the rightnhand scuttle bay, submerging the battery backed sounder (silver thing under the bonnet pyrotechnic).

Might be worth checking the drains aren’t blocked.
 
Hi mine some times does this i just unlock and then re do it and it seems to be ok. I just presume i was either to slow or to quick with the double press.
 
GARETH said:
My alarm sounder needed replacing recently. It started misbehaving by going off at anti social hours, and Beeping when I unlocked it!

Diagnosis was water pooling in the right hand scuttle bay, submerging the battery backed sounder (silver thing under the bonnet pyrotechnic).

Might be worth checking the drains aren’t blocked.
Click to expand...


I remember reading your post about it.

The 2 audible beeps on unlocking are due to the security systems detecting a fault with one of the security sensors.

There must have been a fair amount of water pooling in that right-hand corner of your car to submerge the ‘battery back-up security sounder’. It’s attached up onto a bracket on the side of the bulkhead panel (TOPIx pic attached).

I’ve already checked the area for water or any debris (leaves etc) and all looks ok......will be keeping an eye on it now and again though! If I end up replacing the ‘sounder’ I’ll be able to see and access the drain/s better when I'm doing the job.
 

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Yes a job for an Indy or a good auto electrician, hope you get it fixed
 
👍

Once I have the diagnostic done, hopefully it will pinpoint the problem which could be the ‘battery back-up security sounder’ (incorporates Tilt Sensor). I can then order the part and fit it myself.
 
Had the diagnostic done at my local independent which showed ‘B1D17-96 Permanent fault – Battery backed sounder’.

This concurs with the Jaguar TOPIx Diagnosis & Testing information I have which says......‘B1D17-96 Battery backed sounder – Component internal failure’.

Ordered the part this morning from main dealer (part number C2D47174 - priced at £124) so I’ll be fitting it when time and weather permits.
 
Glad you found the problem
Might be a bit late, but the part is a standard JLR item for many cars

£49.99 here and £5 shipping - in stock
https://www.prestigecarpartsuk.com/products/jaguar-xe-alarm-siren-2015-on-c2d47174-eh2219g229ba
 
Thanks 👍

I’ve already seen it, but what put me off is the manufacture date of 13/11/2014 which is shown on the rear image of the sounder. I’ve also seen others which are cheaper.

As my car is a 2016 model and the battery back-up security sounder has a ‘Component internal failure’ I’m not taking any chances. This is why I ordered a new one from the main dealer (£124) which comes with a 2 year warranty.
 
Cheers 👍

I’ll be posting the fitment info after I’ve done the job.....always handy to refer to.
 
RPSN said:
Thanks 👍

I’ve already seen it, but what put me off is the manufacture date of 13/11/2014 which is shown on the rear image of the sounder. I’ve also seen others which are cheaper.

As my car is a 2016 model and the battery back-up security sounder has a ‘Component internal failure’ I’m not taking any chances. This is why I ordered a new one from the main dealer (£124) which comes with a 2 year warranty.
Click to expand...

I believe they are all the same and have been fitted on various JLR's since 2009, but if you're more comfortable with a 2 year warranty then that's a sensible spend. You're saving the labour in any event :)
 
Even if they are the same, some of them are susceptible to ‘Component internal failure’ as time goes by (including mine).

The extra £70 or so and a 2 year warranty on a new main dealer part is definitely worthwhile in my opinion.

As you say, I’m saving on labour charges anyway. This more than makes up for the extra £70 (approx) spent on the new part :)
 
I’ve removed the faulty battery back-up security sounder (BBUS) and replaced it with a brand new one that I bought from my Jaguar main dealer.

All is working perfectly and I’m now getting the single audible beep when double locking, no two beeps when unlocking (this was an error tone indicating a fault with one of the security sensors – mine being the BBUS), and the tilt sensor (incorporated into the sounder) now triggers the alarm when the car is double locked then jacked up.

For those who may have the same fault and prefer to DIY, I’ve explained how I did it here (includes plenty of pics which are numbered for reference).....

‘Battery back-up security sounder - Removal and replacement’ https://www.ftypeforums.co.uk/viewtopic.php?f=21&t=6114
 
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