My 2009 XJ has developed a very obnoxious habit of sounding the alarm when I'm 100% sure that a) no one is near the car, 2) all doors, hood, and trunk appear tight, and c) nothing is pushing any of the remote buttons. Last week this happened at a graveside funeral; simply horrible. Anyone experience this? Is there any way to tell what entry point the car thinks was breached?

Thanks,
Doug

 

A common cause, on the X350, of this is the bonnet (hood) switch which is beneath the LH (ie UK passenger's side/US driver's side) bonnet latch. It's caused by oil from the latch working its way down into the switch.

The usual fix is to defeat the switch by shorting it out with a very small piece of aluminium foil between the pins of the connector.

 

Had the same issue, and agree with Patrick the hood release switch was the culprit. A replacement is only $20-30 from Jaguar and is a 5 minute fix.

In my car, the definitive diagnosis was when the "Bonnet Open" message appeared while driving down the road.

 

Thanks to you both. Six other responses on another Jaguar Forum said the same thing. Already bypassed the sensor, so I'm expecting the problem will not resurface. Never saw the 'Bonnet Open' message while driving; could be that it's a momentary failure-- enough to trigger the alarm, but not long enough for me to notice the info center message.

 

Scan for dtc's maybe it will give you a clue?

https://www.jaguarforums.com/forum/x...ndomly-135626/