OK guys.....on this 2009 XF 4.2 premium luxury......the alarm is going off randomly for no reason. I have found note on car windshield that the alarm is going off, and silencing itself without me even knowing it happened.
I don't have the inclination to spend a lot of energy on this.....what is causing it AND... is there a way to simply disarm the alarm system period.? Are there settings options on home screen to just shut off the alarm altogether?????
I am also contemplating just leaving the car unlocked.

 

in the system settings, there's a passive alarm that you can enable/disable. basically what it does is set the alarm to activate even if the car is unlocked.

I've had a similar issue like you, the alarm was just going crazy at random times. I disabled that passive alarm and it solved the problem

 

Common problem has been the hood sensor that is on the hood latch.It fails intermittently and sets off the alarm.

You can replace it with a new one, or just bypass the sensor by soldering the leads to the sensor together so it always thinks the hood is closed, which is better than leaving the car unlocked.

 

The car computer stores the causes of the last 10 alarm triggers. So you can get that read and it will tell you the issue. As mentioned above hood sensor is a common issue. And a really easy diy fix.
It may be the cause of your battery previously going dead so worth resolving it

 

Thanks for responses....not to come off as lazy. I actually have been diy my cars for years, but I can't find anything near the latches that have anything looking electrical. I have port and starboard latches with a center located hook/release lever. I don't see any electric wires or microswitches anywhere. Where is the hood microswitch?

 

Hello,

There is always a reason,

Regards,

Colin.

 

Well this question was posed almost 2 years ago, but I was able to pull the hood latch off a 1960 Ford Falcon and it fixed the problem