Yesterday, I happened to see the lights flashing on our X300 and anticipating what would come next ran inside and grabbed the keys and got back just as it started to blare the alarm siren. Unlocking the drivers door stopped the alarm.

My daughter comes out after hearing the all noise and mentions that this occurred a couple of times before (she is the primary driver of this one). So it's experienced this odd behavior approximately once every 10 days or so.

It's obviously likely to either happen again or get worse, and was wondering if anyone had any clues or recommendations of what to look for. The battery is only a couple of months old and tests great, so I've eliminated what I thought was the most likely culprit. On our Land Rover the hood latch switch is a known failure point that sets off the alarm, so I was hoping someone on the forum knows if there are similar failure points on the X300.

Thanks!

 

Just an update with a little more detail.

Yesterday, I tested for parasitic draw to see if low voltage was causing the problem. Draw was well below spec, so that isn't the problem.

Also, I should mention that car is only locked using the key because the fobs have long sense stopped working. If I understand the system correctly, it shouldn't even be armed if you use the key to lock the car. Yet the random triggers occurred.

 

In case someone comes across this thread while searching the archives, I'll update it with a couple of points.

One, what I stated above is incorrect, the system will arm if the key is used to lock the doors.

Second, so far it's been impossible to determine what exactly sets off the alarm, because it's too random and far between incidents. However, after it going off at 4am, I had to figure out how to disable the system.

If you are looking for a way to temporarily or permanently disable the Alarm, what worked for me was to make sure the car is unlocked and starts. Turn off engine, disconnect battery, and then pull Fuse 4 from the trunk/boot fuse box. Fuse 4 provides power to the Security & Central Looking Module. You will lose the benefit of central locking, but gain the benefit of not waking the whole neighborhood.

Hope someone finds this useful.

 

Some Jaguar models have the ability to log 'LAST ALARM ACTIVATION' in the SLCM.
I don't remember if the X300 has this capability.
It could be a faulty boot lid or door latch microswitch that becomes 'open-circuit' once-in-a-while and sets off the alarm.

I don't have an X300 here right now to see if WDS or IDS can test the SLCM for this feature. You might find someone with a compatible diagnostic scanner the check the module?

bob

 

Thanks Bob, I've got a IDS/SDD clone system (V130) that I've used extensively with our 2004 VDP, but I've never connected it to the 1995 to see if the legacy IDS works. There seems to be varying info on whether it works or not going back to '95 even though it is ODBII compliant. When I have a chance, I'll give it a try and see if I can read any codes off the SLCM.