I have a 2004 xjr and for some unknown reason, the door locks go back and forth locking and unlocking about 2-3 times when I put the car in reverse and then into drive. Has anyone had this before and know what it might be caused by and what the solution is?The rest of the electrical system seems to behave normally.

 

As you will know these cars have'drive away locking' and it sounds like one of the doors is struggling to lock.

What happens when you lock the vehicle with the fob?
.................................................. .................with the key?

In my experience a door lock usually fails because of the micro switch and this does not cause fluttering but you can get other faults.

There is a cable between the handles and locks and one of these could be trapped or stiff.

Check that all interior and exterior handles are working.

I had fluttering once when I removed door card and had not replaced it properly.

I have at this very moment in time just replaced the microswitch in a spare actuator and successfully.

When testing and I had not latched the lock ie shut the door, it fluttered when 12 v applied.

Hence maybe place a spot of oil on spindle of the latch and ensure all doors are properly shut.

 

The fob doesn't seem to cause the same effect. The passenger front door is hard to open at times or won't from the outside. The inside no problem anywhere. Are you suspecting that an interior cable or mechanism might be needing lubrication on the passenger door? As such it would sound like I'd need to pull the door panel.

I do notice that the mirrors don't fold in with the fob, when I hit it twice to lock. They do fold in manually when in the car. Any connection? They seem to give a half hearted move, but don't fold in on locking.

If it's a micro switch, is that located on the shifter area, and is that something I can pry off with a plastic tool?

I just lubed the latches on the doors with lithium grease on the pull out handle and the actual latch as well. Didn't seem to have any effect, but sure it's probably a good general maintenance I've never done before.

 

You have a problem with the passenger exterior handle so that is a clue which you need to investigate.

Don't use double locking-if an actuator fails in that position it's a PITA.

Door mirror motors can become severely corroded or a bad connection at DDM

The micro switch is inside the actuator ie lock and latch.
If it's fluttering the micro switch is ok.

 

So it sounds like I should pull the door interior panel and look at the lock from inside the door frame. Besides the screw at the lock/open handle inside are there any other screws that you're aware of? So it's on the lock mechanism itself? I'll see once I'm inside if there is a sticky or bent microswitch. I didn't understand the part about the double lock? A friend who doesn't have a jag suggested a relay not latching. Any thoughts on that?

The mirrors move fine from inside with the switch on the drivers door. It just doesn't seem to want to move from the fob. When you double push the lock button on the key fob it used to bring the mirrors in.Now there's just a little movement..

 

Small screw hidden behind interior chrome handle

Lie down under an open door and look up vertically and you will see a screw under the door pocket.
Two screws in large interior pull handle
Strong plastic clips all around the edge of the door card which need to be levered off.

Card lifts off but cable still attached.

Then remove moisture barrier-screws around edge


When you double lock it means that the door cannot be opened from the outside or the inside.

If the actuator fails in this position, and it does happen,then you have to cut into the door

and destroy the actuator to get the door open!

Is your key fob working properly? ie headlight button and trunk open button?

 

The fob opens the doors, sets the emergency beeping and lights and does open the trunk, so I think the fob works. I did have an experience yesterday that's making me wonder if it's in the gear shift area. I dropped off my customers, rolled down the passenger window to speak with them, and put the car into gear. The locks probably fluttered at least 5 times when it was in reverse, so I had to quickly put it in park as it was rather noisy. Thinking that's directly related to the gear shift movement. Is there something under the trim around the gear shift that sets that "lock the doors on drive" that maybe I can pry(?) up the trim around it and see if there's a bent or sticky microswitch there?

Thanks for the the info on the door. I might have to tackle that if this other idea doesn't shed any light.

 

Yes there is a switch there for drive away locking but I think the problem will be the cable in

one of the doors.There is a cable between the interior door handles and the actuators.