Hello,
So my 1999 XJR 100K miles is new to me as of 3 months ago. I have some suspicious things happening with my automatic locks. As I drive they will lock and unlock randomly. Also, this makes the windows all role up as well. Sometimes it will happen 6 or 7 times before it stops.

Sometimes, if I put down all the windows in the first key position and then start the car the windows will stay down for the rest of the time I am driving. I have even been able to turn off the car with the windows down and come back to it and drive off without the windows rolling back up and the doors locking and unlocking. But it usually ends up with the windows rolling up and the locks locking and unlocking.

I have replaced my SLM with a used one, it was good for 1 day. An independent Jag shop told me it's not the SLM,BPM or the ECM. Any help would be much appreciated.

 

Try driving the car using the key only (leave the remote at home) or try using another remote, if you have. If the random lock/unlock stops, the problem is in the remote. If this is the case, open up the remote and inspect and clean the sensor points on the PC board and the rubber pads that touch them when you press the buttons. Rubber (and other) gunk accumulates on the sensor points over time causing the remote to send random signals.

 

I have been driving the car without the remote from the beginning. I just bought new batteries and was going to reprogram it sometime this weekend. Also, the car also did not come with its green key.

 

In that case, you can next try getting the remote to work (inspect and clean the sensor pads anyway) and once you start locking and unlocking the car with the remote, the problem may disappear. If this does not solve the issue, I would next check the Door Locking Relay, the Central Locking Switch and the Not-in-park Microswitch (see attached diagram) for any poor contacts in the connectors or in the switches themselves.

 

Maybe a hard battery reset. Often works. Pull the negative cable and touch it to the positive post. This drains all capacitors and resets memories.

 

So it looks like I had to set up the remote to fix the problem! Fingers crossed it sticks. Now I have to figure out why my airbag light won't go off?

 

Does the air bag light flash a certain amount of times on startup, or just blink off once and then stay on? If it just stays on it could be a bad connection somewhere, check the seat controller module connectors, etc.

 

Ok, so the lock unlock is happening again. It is much less frequent but it's still happening. What does the hard battery reset do exactly? Do I just need to touch the positive with the ground cable once? do I hold it on for a few seconds? thank you.

Tim

 

Hold the negative cable to the positive post for a few seconds. This empties all the capacitors which provide a latent charge for many modules including the locking module.

 

Ok, after the hard reset everything was good. Now the problem is back. I have only been using the remote to lock and unlock the car. Also, the airbag light is off now but the check engine light is on. It gave me a little bit of a rough idle but smoothed out cam tensioners? Any more ideas on the lock, unlock issue?

 

Ok, so I know the Not-In Park Microswitch works, I ordered a door locking relay today. I also wanted to check the ground and am wondering if I just need to pull hard on the LHD footwell kick panel or do I need to unscrew something first? I'm 6'5" so the fewer times I have to fold myself under the dash the better. Also, is the central locking switch in the driver door?
Thank you,

Tim

 

Interesting what time does, seeing problems I've never seen on these 308's.

On my 00 VDP SC, I had an abrupt issue of LH heelboard fuse #2 popping. This started happening after I used the key to roll all the windows down. Replaced the switch pack, lasted a day of course. Decided to be weird and turn the key to the lock position this time, making sure to feel the barrel reset. I was going the other way with it, turning clockwise and then feeling it rest back to neutral.

Crazy, right? Yeah well, fuse hasn't popped since. Works for me, maybe I'll disconnect the power to the key barrel or something - I use the remote all the time anyways. Definitely don't recall seeing an issue like this.

I'm curious if you are having trouble with the key barrel as well. My buddy and I assumed it had no electrical connections or anything.

-All after 3,002 hard resets, of course.

 

I am also suspicious that this may be a flood car.

My lock barrel is a little draggy but it locks all the doors and roles down all the windows. The heel board you are referring to, is it in the front LH or rear LH? I was told to check grounds also and I haven't been able to get the front LH cover off, is there a trick?

 

Did the locking relay work?

 

I had the same fault with mine after taking the dash out to fix a screen heater blower problem, turned out to be a bad earth under the passenger side (UK-RHD) foot-well?

 

Sorry about that one- this is the rear drivers side fusebox near your feet. Same here, mine works fine too. I havent used it since it stopped blowing the fuse after leaving it be. But you would know if you fuse was popping like mine, bringing the switchpack window and memory controls down with it.

 

I know this is a old thread but I didn't want to start another since mine is doing exactly the same thing. I don't want to hijack the post but it seems there wasn't a closing cure posted.
My question is what was the cure outcome and have others outside this post had this issue?
My locks lock and unlock at random while driving. Along with windows rolling up by themselves and won't allow me to roll them back down atleast for a few miles. Ideas?

 

After reading about this, I’m wondering if your problem is with the drivers door lock cylinder and potentially one or all of the door lock assemblies sticking. We’re starting to see more door lock issues on the X100’s, X300’s & the X308’s. Most of the time the fix is that they need to be serviced. Cleaning/lubricating all the key cylinders (door, trunk and ignition switch) along with all the latches in the car (4 doors, trunk and the hood pins). All the old grease has hardened up and isn’t slippery like it used to be. I believe that the actuators could be stuck between lock/unlock because they aren’t free anymore. Going over bumps could potentially be enough to nudge the sticking actuator into the lock or unlock position and cause your issue. I would certainly do this first before chasing electrical gremlins. To really do this job properly the door panels would need to be removed to access the actuators. Unplugging the electrical connector on the bottom of the actuators prior to servicing is highly recommended. When you clean/lubricate the lock assemblies, you’ll want to manually lock/unlock the actuators quickly several times to really work the grease down into the pivoting points where all the friction is at. If you leave the actuators plugged in while servicing, all the doors will lock/unlock and will overload and stop working until the actuators cool down. Unfortunately this isn’t a quick and easy job but, my car is 1300 units away from the last X308’s produced and I’ve had to do this already. Old car life! 😎

 

I am with A2B on this one. Especially when the windows rolling down starts to occur. The door lock
actuator is engaging in a random fashion. Before you invest a great deal of time in disassembly, I
would spray a generous amount of spray cleaner into the drivers door lock assembly and engage all the
functions with the key inserted, then apply a liberal amount of lubrication and discern the results. A2B
has a great deal of familiarity with these cars and knows what he is talking about.

 

Thank you A2B and Randy.

I think you guys are right. Logically that's what it feels like the car can't make up its mind and it's intermittent. Would be nice and impressive if it would atleast play a tune locking an unlocking rhythm lol
Another reason I think you guys are right, living in Michigan where we like to have the dirt road driving feel on asphalt roads, even the liquid crack sealer patch work you can feel, is most likely giving it enough vibration for triggering.
I'll look at spray this weekend and give results (hopefully closure ) on the issue.