My 99 XJ8 alarm will go off if I open the trunk ("Boot" for my friends across the pond) and the doors are still locked. It does not happen right away either which is odd. It does take a couple minutes for it to go off. Maybe a security feature Jaguar put in to remind you its still open? Either way, I unlock my car now before I open the trunk

I did have an issue with my key fob where it was unlocking my car at night. Took it apart and gave it a good cleaning with alcohol and q-tips and the problem went away. I think there was moisture in the fob that was shorting the line and unlocking the car. Worth a shot.

 

Certainly sounds like a possibility and easy to check.
Jaguar owners usually complain their remotes don't have any range!
Keep us informed.

 

Still having problems

 

Thanks for all the suggestions guys.
Took the batteries out of both remotes for 24 hours. No change.
When parked outside my house all day, everyday with locks and alarm engaged I have no problems. But overnight the boot lid pops every night now, so the problem has worsened. Why overnight and not during the daytime. Is my Jag afraid of the dark ? I can only assume its temperature related.
Today I secured the car with the remote and then popped the boot using the remote key. It took half an hour before the alarm triggered. Did the same but with the key in the lock and the alarm sounded after 10 minutes.The petrol filler cover remained locked. I think these are both actuated by the same circuit in the locking module.
My boot/trunk lights are not working again and as these are controlled from the latch switch I am begining now to suspect a faulty latch but cannot for the life of me think why it would energise by itself.
Project ongoing

 

OK so find the SLCM and see it it looks tired.

 

Does this problem happen when you travel. My neighbor used to sometime open my
garage door with their remote and vise versa. I had to change my garage door opener
to solve it. It sound like you are getting a remote signal that sets it off. If you take your
remote in an unpressurized airplane, the buttons will be depressed after the flight. It may not be the car at all. You may just be getting a radio signal from an unknown source.

 

Finally some progress.
Had time this weekend to go deeper. Found one broken wire in the loom on the boot hinge and three frayed wires.
Repaired these and then found that the micro switch in the boot latch sometimes sticks. Tried the WD40 but did not repair so I have ordered a new one. Should be here tomorrow. £46 from Jaguar
Fingers crossed.

 

OK. Fitted the boot lock microswitch and the boot/trunk lights now work as they should. Thought that this was it as the alarm now has not sounded for the last three nights but I still find that the boot lock is still giving problems. Twice now I have found the boot lock mechanism has released but no alarm, so still investigating.

 

When you say "boot lock mechanism has released but no alarm", do you mean the display message "boot open" or the panic alarm siren??

Both my wife and I have a problems sometimes when we get into the driver's seat our left knee hits the boot release button and the boot open message is displayed.

Jim Lombardi

 

For the first month I owned my XJR, I did that almost every other time I got into or out of the car.

I think his issue is happening during the middle of the night though.

 

No. Every morning before I touch any of the keys or the remote I leave my front door and check the boot lid. It looks closed but will lift up without me touching any of the mechanisms. The car is still locked and armed. The original problem was that it was sounding the cars alarm. That is now cured with the repairs. I just now need to determine what is popping the lock. I intend now to disconnect the linkage to the motor and just use the key for a week and see if the problem changes. Watch this space and thanks guys for all the great input.

 

On the basis that anything may be worth a try, may I make this suggestion.
Under the front left wing, in close proximity to the left fog light, is a unit called the "Intelligent Security Sounder". This unit is directly concerned with key fob reprogramming, amongst other things, and sounds a beep when key fob is reprogrammed. In its position it is constantly sprayed with water in wet weather, and can fail without warning. It is powered through fuse #3 in the engine management fuse box, under the bonnet. Try disconnecting this unit, and see if that helps. If it does then disconnect the cable supply to the unit, and replace the fuse as that fuse also powers the a/c water pump, and the fog lights. You can replace the faulty unit at a later date, though it is not entirely necessary. Security alarms are not disabled by leaving it disconnected.

 

Hi everyone.
Gone a week now without a hitch.Didn`t get round to disconnecting the latch motor but I did lubricate all of the linkages and the key lock. Could be that my electrical repairs plus this have put the problem to bed. I will only post again is the problem returns.
Thanks again for all your interest.