The car alarm on my X350 keeps going off randomly after I lock the car. I check all the doors and latches to make sure everything is closed and the problem still persists. Sometimes I let the alarm continue until it stops, but then a few seconds later it continues to keep going crazy again! Any ideas on what it could be or how I can fix this annoying problem?

 

JagMan,

Check the trunk to make sure the plunger on the trunk electrical connector is making full contact with the plastic panel on the lower part of the trunk.

Same deal with the hood. Open and slam shut. Make sure the electrical connector makes contact.

Thanks - Anthony "Bonano"

 

Change the bonnet switch or connect the wires together that's what was wrong with mine when the alarm kept going off

 

To echo the above, in 99% of cases it will be the bonnet or hood switch, it is mounted to the underside of the right hand latch if you are standing looking at the engine bay. The best way to determine if the switch is at fault is to simply short it out with a piece of wire on the pins of the connector. If this stops the alarm you can either swap the switch out or keep the shorted connection as I have done.
One point to note is that Jaguar issued a TSB relating to the failure of these switches which is exacerbated by lubricating the bonnet catches. A point to watch out for if you replace the switch.
If you have the Jaguar dealer diagnostics, SDD, there is a facility in it to determine the last alarm activation reasons.

 

I had this problem on my 2004 xj8. It was especially bad if it went off at night. It turned out to be the hood open/closed sensor. New sensor, problem has not happened again.


Tom

 

Had the same issue on my 2008 XJ..... As stated the hood switch was the culprit and a quick cheap and easy fix

 

Another vote for the hood sensor, my XJR 04 has this issue right now as well.

EDIT; Where is this part on the JEPC?