I have somehow misplaced my one and only master key for my 2000 Jaguar XJR. While working on the vehicle, the key may have ended up in the trunk or been misplaced elsewhere. The issue is compounded by the fact that the car has been garaged for about two months, and the battery is now dead. I only have the green valet key, which cannot be used to open the trunk with its key-hole access option.

If I could restore power to the vehicle, I think I might be able to use the trunk-release button on the dashboard (I do not believe the car would be in "valet mode" once power is restored--if it were, the trunk release button would not help...), but I cannot access the battery to jump it because it is located in the trunk.

Upon opening the hood, I found a fuse box on the driver's side of the engine compartment that appears to be connected to a thick cable. I assume this cable is directly from the positive lead of the battery, but I do not have a wiring diagram for confirmation. I discussed this with a local Jaguar technician, who agreed that it likely is the positive lead. He suggested that I try jumping the vehicle by connecting that thick wire to the positive lead of a working battery and grounding the negative lead to the Jaguar chassis. However, when I attempted this, there was no sign of power; neither the interior lights nor any other electrical components activated. It’s possible there may be a continuity issue with my jump—I'll check for that later with a voltmeter. But I'm also wondering if there is something preventing power from being accepted when applied in this manner (safety circuitry?).

Does anyone know if there might be a better jump-point for this vehicle that is accessible from inside—either in the cabin or in the engine compartment?

Thank you for any help/advice. Worst case, I can have a new key made based on my VIN--but I'm trying to avoid that. I feel that I'll find the key sooner or later... It's just tricky if it's in the trunk!

 

You can't jump start from the bulkhead connection, but you should be able to charge the battery or apply power to open the trunk. On the XK8 there are two of the positive connections, one on each side, should be the same for yours.

 

OK, I do not need to jump start--I only need to get power to the accessories, However, I was not able to get any power to the vehicle by attaching the positive terminal from a working battery to the screw that secures what I believe is the positive lead from the battery and attaching the negative lead to the car chassis. I do not have positive connections on both sides of the fuse box (I saw an image of that online and that's not the way it appears on the XJR). I'll upload a photo soon...

 

The valet key could be modified to open the trunk lock by filing the tip narrower. Google "tibbe valet" for info.

 

I was just about to write, what 944play wrote: The valet key can be transformed into a proper key. However, I would not dare to try doing this myself with a file. If that fails, you have nothing. I would recommend going to a locksmith, who knows, what he is doing and let him modify the tip of the key professionally.

PS: (regarding title of this thread here): You are still alive, hence, no Darwin award for you...

 

I’ve jump started (and charged completely dead batteries overnight) at the engine bay bulkhead several times before. To make it a little more safe is to place a towel underneath the bulkhead connector before placing a jump lead on the power wire and using one of the top 3 bolts of the shock mount plate as the ground. Don’t use the tall shock absorber stud as a ground!

 

This may seem insane, but when the linkage retainers broke on all the rods, I had to do this and it worked excellently.

 

Attaching power to the false bulkhead (red) and negative (black) to any hard engine ground should provide power to open the the boot from the button in the car.

Hopefully you find the missing keys (the real problem) once the trunk is opened. If not, start running the trap lines searching for a Houston metro area locksmith who has a new key (hopefully two) and fob combo and the software to install it to your car. Dealers are pretty useless (parts no longer available, they say), but many locksmiths working speciality vehicles have stock; but it will take a search.

 

Modifying your valet key is a two minute job with a file.

Originally Posted by steveinfrance
There was a thread on this but I can't find it.
Here are the two keys

To mod your valet key carefully file the tip to 4.5 mm (0.175") diameter for a depth of 2 mm (0.08").
Take the same amount off both sides of the key.
My two master keys measure 4.5 and 4.4 mm at the tip so a bit under 4.5 mm is OK

 

As mentioned above. Make valet key tip look like this. I used a bench grinder. File is more precise

 

You should get power if you jump under the hood cable
Just make sure you have good jump and large charged battery connect the negative to the shock bolts mount that always worked for me small battery won't do it as I tried before nor bad jump cable

 

So here's the update:

Thanks to everyone who offered help--this is an amazing group! I think I did not have a good ground, but the general advice from Jhartz and specific advice of Silverjag0 to use the shock-mount bolts worked perfectly. Once I connected the battery of an Acura RDX to the fuse-box positive lead and the shock-mount bolts, voila! I heard the sound of power, opened the driver's side door, saw lights, and hit the trunk-release button, and the trunk dutifully obeyed and opened. I never thought the sound of the trunk relay would be so consoling! Ahhhhhhh....



For those who don't have a visual on the XJR 2000's under-hood connection points mentioned above, here's what that looks like--thank you Addicted2boost for suggesting the towel, I really liked that idea especially if one the positive lead happened to work its way loose and touch ground on the chassis...


A few other comments/responses:
* Yes, well thankfully I wasn't the winner of an official Darwin award (since that would mean I'd no longer be alive), but for a moment I felt that my life was over (well, just kidding, but it was deeply disappointing!) when I realized the symphony of unfortunate events that led to the predicament I was in!
* Peter_of_Australia suggested that if I were to file the valet key and mess up, I'd have nothing--not to be too pedantic, but it occurred to me: wouldn't it still function as a valet key even if the very tip had been improperly filed? It would seem to me that since both keys (master and valet) work the ignition then that tip doesn't play any role in starting the car but it does play a role in the lock mechanism for the trunk... I can't picture what would be going on inside the ignition lock that wouldn't allow the key to continue to function if the tip is improperly altered as long as no portion of the rest of the key shaft is tampered with.
* It occurred to me that even if the car had somehow ended up in "valet mode" (which would mean that the trunk-release button inside the vehicle would not open the trunk even with battery power if the master key isn't used in the ignition lock), I should still be able to open the trunk using the vehicle's key fob, which I do have and which still works.
* Thanks to Jhartz for the advice about calling around in Houston. You're totally right: The dealerships were not helpful at all. But after a few calls to Jag specialists, I found a locksmith who has a blank master for the 2000 XJR. He said that it'd be a whole lot easier on him if I find the master and I just want a copy, but he did say that he should be able to make a new master from the valet key. He asked me to get back to him after I've had a chance to find the master key.

It occurred to me that if all of my assumptions are correct in the third bullet above, then I really never should need the master key again to drive and use the vehicle normally--that's if the key fob is able to override the valet mode setting. If it doesn't, then the caution I suppose would be to avoid pressing the valet mode button. And even if pressed by accident, it seems that disconnecting the battery for a bit will clear that mode and effectively turn it off again.

I am quite confident that I will find the master key. It's one of those situations where I placed it aside in a--ahem--safe place that I would be sure not to forget, got distracted on other projects, and then outwitted myself...!

Thanks again for all the help!

 

Glad I helped btw your car exact same my car color and wheels though it's xj8 not xjr . Enjoy your cat