My 2000 XK8 doors lock when gear is moved into drive or reverse but do not unlock when moved into park. If the driver's door is opened manually from inside it creates havoc causing both locks to cycle when re-locking with the fob and the horn to sound before unlock is pressed on the fob.The doors then remain locked (and horn stops) until unlock is pressed again when they open. All has to be reset by disconnecting battery to cure this (most of the time). I now have to use the fob to open INSIDE the car to try to prevent this happening. Anybody got any ideas?

 

Don't think auto unlock when in park was ever an option.

Door lock cycling is common when battery is a bit low. I've seen it many times especially in the bitter cold. A quick hookup to the charger and all is well again.

I've seen my car go into deadlock if one tries the door handle before disarming (alarm on).

Problem is that you didn't say alarm was armed when the handle motion causes symptoms. Mind if I double check your description ? Are you saying alarm inactive, use of door handle cycles locks and sounds horn ? Wow I could see this if alarm was on. How's your battery working ?

 

Just had similar, but not identical, symptoms w/ my '97. Locks kept recycling, etc. Replaced the door lock latch mechanism on the passenger side and everything now working normal. (I first confimred that the battery was OK.)

If it is the lock mechanism itself, there are left and right units, so you need to determine the defective one. Both sides were erratic and symptoms varied with using fob or key to lock and unlock. In my case, we concluded the pass side was defective because it was the side that did not open using the fob.

One can find used units for about $50; and they are not that difficult to access and replace. Rev Sam has video.

In my research I discovered the other suspect might be the door lock module, which is a solid state black box device a little bigger than a deck of cards. I bought it at the same time to cover my bases; thinking this might be the problem if the lock mechanism was not.

Both the lock mechanism and electronic door lock module are easy find used. If you want to to trouble shoot using my spare door lock module let me know and I'll send it to you.

Hope this helps you diagnose your problem. Gordo

 

I just noticed a similar problem when I go to unlock or lock my car (with the fob AND if I use the door lock)... the locks cycle back and forth (mainly the drivers side)... and if I use the fob to arm it cycles again and then the alarm goes off. I have my battery on a tender and the light on the tender is green, so I am thinking that the battery has an ample charge. Unfortunately (and hopefully related) the passenger window now doesn't work, and the passenger lock doesn't really move (unless I manually move it then it causes the driver lock to cylce.

GORDO - I am hoping that my issue is similar to yours... what does the door lock module DO? Maybe I should get yours to troubleshoot mine.

DNARRAF - Did you ever get your door lock problem sorted? And if so, what did you find out?

Thanks!!!

 

You have very similar symptoms to what I experienced. My problem was solved by simply changing the door lock actuator. I bought both the actuator and the door lock module just in case the actuator replacement did not fix the problem. The only real difficulty was ascertaining which side was causing the issue. By a combination of trials, it became clear the problem was focused on the passenger side.

 

Found the problem. Only took me a couple of years!! A microswitch after all. The one which is operated by the actuator in the lock. No problem with the switch itself BUT the long springy arm was not pressing down quite enough on the little blue switch button. It is very flimsy to say the least; just bent it up a bit so it presses down fully on the little blue button. I guess the same thing must have happened in BOTH locks as I believe it only needs 1 out of the 2 to be making contact in order to stop the lock cycling and the alarm going off. Done the passengers door. Will do driver's door too to reduce chance of this happening again. The micro switch just clips in and out once you unscrew and take off the actuator. That's a really flimsy bit of kit too; took mine apart just to check it out; full of tiny bits of moving plastic and yet another micro switch - all just asking to go wrong! Why DO we go for jaguars I ask myself. Maybe it is all just the challenge!!!

P.S. I believe you can buy better quality switches from Omron (Omron D2SW-3L3MS) but I didn't bother for now. I've got taking the door latch out and to bits down to a fine art now - takes me about 10 minutes from scratch and I'm 71! Was thinking of applying to the Guinness Book of Records - what do you think?