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X-Type alarm keeps going off


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I have not posted anything on this site before but thought it might be helpful for some if I gave an account of this problem, as I couldn't find any other posts relating to this specific problem.

I have a 2006 X-Type estate which I have had since last August, it is in mint condition with everything working as it should.  However over the last few weeks the alarm has been sounding in the the daytime and seems to only happen when the sun shines! - although not much sun at the moment it happens when the car is parked at work and is quite annoying for everyone.

I usually only single lock the car therefore not activating the internal volumetric alarm, but has a part of the diagnosis put blue tack over the internal sensors but the problem still exists.

Everything else works normally, so I called the local dealer who told me they would charge £130 to diagnose the problem - a bit steep bearing in mind they'll also be charging an unknown amount on top to fix it!  They also said they could disable the alarm siren for the same cost (£130).  The problem with this (which they didn't tell me) is that it does not stop the horn from sounding.

So as I'm not too bothered about have the alarm sounding anyway I set about disabling both the siren and the horn, the challenge was do this but keep the horn working on the steering wheel switch.  Disabling the siren (backup sounder) is the easy bit - front wheel off, remove wheel arch lining at the front and unplug the siren -done!

The next bit was to stop the alarm from setting off the horn.  With a bit of research and managing to download the official Jaguar X-Type electrical guide the solution was quite straight forward. The main unit that controls the alarm is the Generic Electronic Module (GEM) which is located in the driver footwell, the electical guide gives the circuit diagrams and the pin outs from the GEM. Basically the GEM takes an input from the steering wheel switch (horn) and has an output that controls the horns under the bonnet via a relay, because the GEM sits between the two it enables it to sound the horn should the alarm be activated.

The solution is to remove the SW switch input and horn output wires from the GEM and then join them together so the switch then operates the horn directly - like the old cars!

Having done this the car remains silent but the horn still works via the steering wheel - at last! (The hazard lights do flash though for up 30 secs, for me this is not a problem)

The pictures below show the backup sounder, GEM and the GEM pin outs.


2016-03-03 12.14.35.jpg

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2016-03-03 15.35.53.jpg

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Welcome to the club, Julian.

Your post will be very useful in the event of others having the same problem.

Main dealers do charge quite a lot, even for just a diagnostic test. About 4 years ago I was charged £69 for 25 minutes work in solving a diagnostic scan and a deleting of the EML.

I then spent £20 on an OBD2 scanner which I have used a dozen times since to find the issue, saving me a few shillings!




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  • 10 months later...

Hi Martin,

The secondary sounder is located in the left (nearside) wheel arch, to access it you need to remove the wheel and release the screws on the front part of the wheel arch liner pull the liner back and you see it bolted to the subframe.

Hope this helps, if you still have issues with the fuse after doing this I have all the circuit diagrams if it helps.

Rgds. Julian

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  • 2 months later...

Julian, will never be thankful enough for this post!!

Siren is now disconnected (less sleepless nights) and am about to follow your instructions to get the horns to respond only to the SW switch. 

I have just one question for you or any other member of the forum who may know this...does all this count as a vehicle modification of which I should inform the insurer about??? Or mechanic tried to scare me off with this so he could charge me £200+ just to LOCATE the faulty sensor??


Many thanks in advance!



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Hi Anna, and welcome to the club.

I think you might need to look for another mechanic.  I do believe your insurer will not be too happy if you have no alarm connected, so I would be looking to replace the sensor as an eventual cure



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Its usually the back up sounder thats causes the alarm to go off

There nicad batteries inside that fail, cause voltage problems and setting the alarm off

You can replace the sounder but it needs programing

if you handy, I've split them before and replaced the battery inside for a new one, then resealed the case with polyurathane adhesive and cured the problem

Your fix above also works well, if you know someone one with jaguar IDS/SDD software they can plug in and also reprogram a new sounder or disable the sounder as well



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  • 2 years later...

Thank the lord I stumbled onto this post!! For months now my alram has been an issue due to one of the ajar sensors not working properly. ( would love some advice on how to find out which one is faulty and how to repair/replace) however this is creating a very temperamental alarm issue... some days or nights nothing, then it'll go off randomly sometimes up to 20 times in a day! Yes really!  It's now become a more serious issue as the faulty ajar sensor has now either failed completely or has stuck... as the door ajar light on the dash is now on permanently.  So the alarm is sounding at least 3 times a night.  The only way for me to stop it is to simple not lock the car.  Bad design flaw, on Jaguars part, not being able to soft lock the car.  So... having seen your post on how to disable the sounding of the horn is almost a gift from the heavens!  
question: Anyone else having issues with the door ajar sensors? Anyone know what they look like or have a picture of what to look for.  And the main point, can they be fixed without having to replace the entire latch mech. ??

Thank you ...   

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there usually a  switch inside the door lock mech, car years ago use to have a reed switch and magnet operated it when operated

taking the lock out and cleaning out with thin oil can cure it

not sure on the X-type, but most jaguars now the door electrics are on a plug, so you could unplug each door one at a time and lock them manually from the inside to eliminate each door

leaving the driver door till last, then if it still goes off must be drivers door

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  • 8 months later...

I have a 2007 X Type 2.2d SE Estate (manual). The car has developed an ajar alarm from the rear drivers side door, despite the door being firmly shut. This has resulted in the alarm going off at very awkward times of the day - and more especially - at night. It was only when I sat in the car with the doors closed that I saw the message on the dash saying it was open when the ignition was switched on.

I looked on this and other Jaguar forums and found that the alarm switch is integral to the door lock and "cannot" be fixed independently. (That answers the question posed by Blueice!). I removed the door card and the foam liner, undid the bolts holding the switch to the door, removed the linking bar to the internal door handle and tried to remove the switch assembly. I have quite large hands and could only just get in to hold the switch and pull. That was when I discovered there is another rod connected to the top of the switch which I couldn't get to, therefore I couldn't extract the switch, so I gave up and put it all back together.

So, looking at this post, specifically Coastriders entry, I am wondering - as the door ajar alarms are all connected in series - if I were to put a link between terminals 15 & 18 of relay CA87 in the GEC module, that would dupe the system into seeing a "closed circuit"? If so, this would have the effect of not having to go to the expense of replacing the faulty door switch mechanism whilst retaining the "locked and alarmed" state for the remainder of the car when activated, ignoring the rear driver's door.

Any thoughts on this suggestion? Anyone know how to remove that top connecting rod from the door switch?

Also, I am now suffering from the tailgate glass intermittently opening / closing / locking when it feels like it. I think, from reading other comments, that if I'm lucky, WD40 might cure it or remove and clean the switch assembly on the glass itself. Thanks to COVID19, I have plenty of time on my hands.

P.S. As it was suggested that these cars have voltage sensitive systems, I renewed the battery as a means of ruling that possibility out. (It was 6 years old, so might have needed it anyway) It made no difference but at least it is ruled out as a possible cause.

Edited by Mick the hat
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Hi Mick,

I wrote this post some years ago now but remember after rewiring the alarm/horn system I discovered it was the driver’s door causing the problem.  As the door switch is an integral part of the lock mechanism which is fiddly and expensive to replace I ended up fitting a reed switch between the drivers door card and the end of the dashboard and wiring it to the appropriate door switch input to the GEM.  This enabled the lights to come on as usual when the door was opened.

Your idea of linking pins 15 and 18 on the CA87 connector on the GEC module would work perfectly in terms of preventing the alarm being triggered.

In terms of your rear tailgate glass it sounds as if you are on the right track, possibly moisture has got into the switch and caused some corrosion, as mentioned WD40 would certainly chase out the moisture.



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Thanks for the confirmation Julian. I'll have a go at both the bypass link and the tailgate glass switch and let you know how it works out. 

Also, if anyone does know how to extract the rear door lock safely, I would still like to know, as I would prefer everything to be working properly as it should. It is an old car and has 132k on the clock but having recently forked out £1200 for a new DMF/ clutch assembly and £180 for a custom exhaust part ( discontinued, thank you Jaguar!) I would like to get reasonable use out of it. 

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  • 1 year later...

Hi  New to the site. 

This is great information as I have exactly the same problem with my 2005 X-Type 2.2d Estate.  Just for clarity, please could you confirm which wires are to be joined in the diagram of the Gem? 

 SW switch input = Horn SW Switch (IP6 Pin20 BG)

and horn output wires = Horn Relay (IP5 Pin14 B)

Are both in the GEM as I am not sure why the  backup sounder is shown?

Many thanks in anticipation


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Hi Steve, The wires to join are ones you have mentioned in your question, the wires that go to IP6/20 and IP5/14. Simply cut the wires close to the appropriate GEM connectors (IP6 & IP5) and solder them together or use a crimp joiner.  The backup sounder plays no part in this, but has to be disconnected so it doesn’t go off.  From memory its located inside the front N/S wheel arch.  I hope this answers your question.  Rgds. Julian

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Hi Julian

Many thanks indeed for your quick reply.  I just wanted to check my understanding was correct before shorting out anything... :)  



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