Both scottjh9 and myself are having the same basic problem, although his seems to be a little greater.
https://www.jaguarforums.com/forum/s...-maybe-211809/

We have an apparent loose key in the cylinder that does not make contact all the time and as a result I will get a "park brake failure" as he does.

I can move the key to get all beeps when the door is open and one beep when the key is inserted by no further unless I push in tight or slightly turn the key to the left or right. When turned on, the car will give a steady beep when I have the door open but if I screw around with it a touch it will generate my park brake failure when on so it must be doing when hitting a bump or my accidentally hitting the keys ect. when driving and thus when my yellow warning comes about. This is happening with both my keys and the valet key.

Are there any suggested workarounds or anything that can be done short of getting a new lock cylinder at some $6-700 bucks?

I have always kept the cylinder sprayed several times a year with lubricant like a silicon.

There is a TSB about the cylinder, but for a different reason, but would this help at all or any adjustment that can be made, once we pull this out. (see attached)
Finally and maybe a silly question, is the loose key condition caused by the lock cylinder or the lock switch?

If either is changed is reprogramming required or is the key recognized as valid by other parts of the system?
Thanks

Tom in Dallas/Plano

 

I think this tsb applies to that little flap in the switch...I don't think that affects the key being loose....I may be wrong but at least the tsb shows a lot of detail in working with the switch in case a new tumbler is needed to correct the loose key issue....I know if the flap does not return to it's home position the vehicle still thinks the key is in and will not lock electrically and the modules will stay activated and drain the battery

 

This worked for myself and the other user who commented scottjh9.It appears the weakness in my cylinder is near the beginning part and does not hold the key in all the way that it should- which is why no beeping when the door is open. If I push it slightly forward then I get g beeping. When driving and I hit a large bump, then I get the stupid light sometimes.

So I said- what the hell and put 2 tight wraps of black electrical tape on the key below where the cut is made and low and behold, my situation is fixed. Even when in the cylinder with the engine on or not, I have zero problem and the tape is not scraping anything and would seem to hold fine. So the black FOB now has a black color up to the cut of the key and everything is working fine, bumps and all or taking my hand and trying to force the issue by moving the key in the cylinder. I suspect we all get quick and lazy when turning the car off and withdrawing the key on a downward ark and weakening the front part of the cylinder.



Tom in Dallas

/Plano

 

Worked for me too and mine was worse.... apparently I was wrong about the flap in my previous post...it does clamp the key in position otherwise the tape would not make a difference....thanks Tom for thinking outside the box
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Wow, that's great you were able to figure out a fix. I offer you a tip of my orthopedic hat.

I do wonder about the durability of the tape. Perhaps if it fails, you could try some heat shrink tubing instead? Just a thought, it might hold up better. Two styles are available, plain or adhesive-lined. I bet the adhesive-lined stuff would last a long time.

 

I will try and see, but the general concept saves a bunch of money and time and unless you have the IDS, having to play around with the (*******)ship of which I would give the car away before I did that again..

TBB

 

Good thinking Karl...will get some today at AutoZone

 

update to this thread....i tried heat shrink, but it was too big around when shrunk.....i had the smallest that would fit over the key shank....oh well,, worth a try....my original loose key has gotten worse over time and the tape works great but now I will try the tsb Tom posted....doesn't look bad to do as long as I do not fumble finger the insert and everything goes boink...JLR only gave their guys .6 hrs to do the whole thing, so it must be pretty straight forward.....besides I have 4 keys( 2 main and 2 valet) and when my daughter drives the car the loose key sets a park brake light, which means really nothing, and she gets nervous.....I know, tell her to stay out of my car and problem solved, but once in a while she drives it if I have her car tied up.....besides I need to lay on my back with the door sill crammed against it for a bit to really appreciate the guys that do this for a living everyday and still help others out in their spare time

 

Im gonna try this. My key is loose but nothing happens bc of it. But I hate the sloppiness

iill try my ultra thin heat shrink forst though!

 

Try tightly wound black electric tape first

Tom

 

Lol! Too late!

Works like a champ!

 

super!!!!!!!!!!!!!!!

Tbb

 

i now remember why the shrink did not work for me...at the time my fobs were not working and I had to use the key to operate the door locks....the shrink was too large to go into the keyhole, but did work great in the ignition....fobs have been working for awhile now and I forgot the situation....found my shrink tube and now both main keys and 1 valet are fixed....leave the other valet alone in case it ever gets used as intended....happy days again with no switch jiggle or key in circuit failure code.........thanks arrcuda and tom for giving me a memory jog and leaving my key switch alone....thread resolved for me

 

So as I was cleaning up I found a connector gasket I left off a WSS. While putting it on I think I realized what happened to cause the faults. I dont think I hadthe connector fully engaged.