Alarm keeps going off

[c.neil59458]

Hi

I have just traded in my old XK against a newer 2008 X150 convertible and the alarm keeps going off.

I have checked the vehicle settings and it say alarm triggered by inclination sensor.

This appears to happen when i double lock it but if i single lock it then leave it a while before double locking it seems to be ok.

I know the easiest solution is single lock it but id prefer to double lock it to save battery drain.

I turned of the sensors in the car through the infortainment screnn and tried it again but it still goes off

Can anyone enlighten me as to cause and solution please

Chris

[Andy P]

Hi Chris,
If I had an issue like yours the first thing I would try is a Hard Reset.
Follow the instructions in first photo(MAKE SURE YOU HAVE YOUR RADIO/INFOTAINMENT CODE FIRST)

The Hard Reset can fix a lot of issues relating to the electrics.
Might be worth a try.Sorry I can't be more helpful.
My brother in law has a 2007 X150,lovely looking cars.
Hope you get the issue sorted so you can enjoy your car without any issues.
Take care.
Andy

[mike020150]

Many alarm issues are caused by failure of the rechargeable battery contained inside the alarm sounder. After a few years, it no longer holds a charge and that can cause spurious alarm incidences. Unfortunately, Jaguar treats the whole sounder as a replaceable item (about £120) rather than just being able to replace the battery itself. Owners with the ability to cut open and reseal the sounders have been known to replace the batteries but it is a bit of a hassle for most folk. Mike.

[c.neil59458]

Thanks for the replies fellas

I have only had the car a couple of days so will see how it goes but it does seem only to happen if I double lock straight away. If I single lock and leave for a while before double locking it doesnt happen. Fine on the drive but a bit of an inconvenience if out and about.

I will get code reader on it at the week end and then try your suggestions.

Chris

[JimMann]

Hi Chris, just to let you know that there will be an article on a home service replacement of the batteries in the secondary alarm sounder in the February 2022 issue of the JE magazine, Modern XK column. It will be for the X-100 version of the car, but very similar fix to that required on the X-150 model, if it turns out to be the same issue as that which Mike calls above.
Jim Mann

[andypryce]

Interesting. I replaced the ‘intelligent sounder’ on my X100, waste of time as the replacement one obviously had dead batteries too. I presume Jaguar were not that bothered about the longevity of rechargeable batteries over a period of years. This sounds to me more like the main alarm though?

[JimMann]

Hi Andy, my understanding of the alarm systems is that the primary alarm uses the horns (and the main battery) to warn of an incident, whilst the secondary alarm, with its rechargeable batteries, is the unit that provides the 'chirp' on double locking of the vehicle (assuming the 'chirp' is not set to silent) and is an independent sounder. It is there to warn of an incident in a situation where the main battery / alarm has been interfered with in some way.
I am sure there are those on this Forum who can provide a more technical response to this question, but from Chris we do need to know if it is the primary or secondary alarm that is sounding off.
Jim Mann

[andypryce]

Yes Jim that is my understanding too.

[c.neil59458]

Hi Jim

It is the main horn alarm going off but only when i double lock. If i lock it and leave it for a few minutes then double lock it it doesnty go off

Chris

[andypryce]

The inclination sensor I think is situated in the boot ( on the X100 it is definitely) and senses for someone trying to tilt the car, eg jacking it up. I am not sure if it’s accessible easily, if it is I suggest the simplest thing is to unplug it, assuming it is easy to locate.

[JimMann]

It is possible to disable the tilt sensor from the Touchscreen, but it is only valid until the next engine start. See your Owners handbook, or go to Vehicle Settings / Security / Intrusion Tilt - On / Off. This function is typically used during a recovery operation, or if travelling on a ferry.
Jim

[c.neil59458]

Hi Jim

I have done that without knowing it only lasted one cycle.

I put a code reader on it and nothing showed up but still have the warning message in vehicle settings/security through the screen.

An additional development is that if I double lock it I get a strange noise from under the bonnet, drivers side, as the mirrors fold. I can only describe the sound as a distorted high pitch squeal that varies in pitch and volume then stops. There is then a delay of several seconds until the actual main alarm sounds.

I was going to try and record it today but it has been very wet all day here in yorkshire....

[andypryce]

Bizarre. Perhaps you could use the services of a local auto electrician to dig a bit deeper? Avoid main dealers at all costs unless you have loads of spare cash!

[mike020150]

Unless your code reader is either the Jaguar full diagnostics version or the Autologics equivalent, it is highly unlikely to be able to read security system faults. The location of the strange noise does implicate the sounder unit. As mentioned previously, these units are known to fail and cause unusual problems. Mike.

[JimMann]

Hi Chris, as Mike suggests, the new noise would seem to point towards the secondary sounder being somewhere in the fault matrix. May I suggest you turn off the tilt sensor from the touchscreen and then exit the car and attempt a double lock? If the new noise is no longer present, then that would confirm the secondary sounder as an issue, i.e. that's the sounder that makes the chirp on double lock.
A full scan by Jaguar or Autologic should then point better towards a problem and a potential fix, but my money would go on the secondary sounder, which is of course battery backed by its own rechargeable battery pack that is not user serviceable - unless you are prepared to do some surgery on the unit.
Jim