pulled the car out of the garage to clean it (garage) today, while sitting in the sun the alarm start chirping, I hit the button it shuts off and on to cleaning I go. 10 minutes later is does it again, again I use the key fob and shut it off. another 5-10 minutes later it does it again, this time im hitting the key fob and its not fixing it. I finally use the key in the door to stop it. I then get in start the car (with door open and leg outside) and its fine.

About an hour later I get in the car to pull it into the garage, start it up with the door closed and the alarm just blares steady..... so I drive into the garage and shut her off. Thought maybe the heat (not that hot here maybe 70) cause something to happen. Anyway, about a hour later I go in the garage, key fob works fine, everything works as its supposed to then I get in (again, door open leg out) fire it up , shes fine...... then I close the door and the horn starts blaring again.

I did swap out the batteries in the fob for the ones on my VDP and it did the same thing.

So... battery is charged fine but I did have it unhooked yesterday for another reason that had nothing to do with the car. I didnt drive it since I put the battery back in this morning and it is tightened good. Maybe un do it and redo do it again in a while ? Resetting the system ?

35 years of Jaguars and some whacky things have happened but never this one.

 

Maybe some resetting is in order, otherwise the BCM might be dying on you.

 

To reset a key fob after disconnecting the battery, you need to 1) stick the key in the ignition but don't turn it yet, sit behind the wheel, pull back the left stalk that operates the birghts, while pulling back turn on the key to the first position, pull back the stalk about 4 times until you hear a beep, and then push each of the buttons on the fob until they beep....If you have done this and your security system operates in strange ways, remove the security module from the trunk, open it, disconnect the ribbon cable at both ends and clean the contact surface gently. If you have never had intermittent problems before, its probably just a matter of resetting the fob....if you have had these kind of problems before, the ribbon cable has probably finally worked itself loose enough to misdirect the flow of electrons from time to time and needs to be disconnected, cleaned and reconnected.

 

Hard reset entire car, pull the negative cable, touch the positive post. The security module is sensitive to battery swaps...mine did something similar.