In my first post on my recently purchased 2003 XJR, I wrote how it showed up on the trailer locked with the key in the ignition. Hauler swore he did not lock it. Working on it in garage. When ever I work on a car, I always leave a window down so no fear of getting locked out. Key in ignition in zero position. Locks itself. I thought maybe I hit the plunger. Sometime later did again. Is this a gremlin or some programmable feature?

 

There could be a number of possibilities. To help narrow it down…

To the best of your knowledge, is there anything else electrically going on with your car?

Did the car come with any fobs?
If so, how does it look inside the fobs?

When you open the doors individually, do they all turn on the interior lights?

The more I think about this, you might want to remove the drivers door panel. I’m wondering if at some point someone had lost their keys and had to get a locksmith to unlock the door manually and perhaps damaged the lock rod and could be on the verge of locking itself. It’s hard to explain exactly. If you were to roll all the windows down, I wonder if they would roll up on their own as well as the doors locking?

Is there any water in the trunk or was there ever any that you know of?

I've heard of bad BPM’s causing this.

 

I know that later models have a factory/dealer setting that locks the car after some time
but even those will not lock the car if it detects the fob in it. Did yours come with a fob?

 

Yes. Working fob.

 

Been a REALLY long time since I did configuration during New Car PDI but there is PASSIVE ARM ENABLE that can be chosen (enable/disable) with PDU, WDS or IDS.

I used to go through the list with the customer when they bought a new car to get it the way they wanted it.

 

The ignition switch as you remove / insert the key makes pin 4 to 5 linier switch to " make " to begiin a lock up sequence for the alarm system to go from driving mode to go to sleep / parked mode

There is a fuse the shipper may have pulled to keep the alarm silent and you may and I say may be able to do a hard reset beyond the simple positive battery post removal that would bring the security system logic steps back to 0 state if stuck in a odd state

I don't have the X308 , but the ignition switch is the same and part # as X300

 

Had some more info for you but did not transmit , maybe after nap