I searched the forums and cannot find an exact answer to this question:

My 2004 XJ8 came with only one key. I can buy a new keyfob on Ebay for around $89 and have a local locksmith that can cut the blade for me.

My question is; if the blade is cut, is that enough to provide me an emergency spare to at least start the car?
Does the car also require a signal from the keyfob transponder to start?

In other words, until I have the keyfob programmed for additional functions (door/ trunk lock/unlock, alarm set, etc.) will it at least function to start the car?

With other cars, I've been able to use the key blade for basic functions (manually lock/unlock, ignition start, etc). But of course, Jaguars are not like other cars.

 

Hi Wayne,

It is easy to program the new remote keyfob so all its intended functions will work with your car. You need to have both your original remote keyfob and the new one together. Here's the procedure that worked on our U.S. spec '04 XJR:

1. Open the driver's door.

2. Pull and hold the highbeam selector arm/stalk toward you.

3. Insert the ignition key and turn the key to the first position (Accessory).

4. Release the highbeam selector arm and then pull and release the arm four (4) times. After the fourth time you will hear a chime.

5. Press the lock button on each remote to program it in. There is a time limit in which you must complete this, but I can't recall what it is. You don't have to rush - you have a few seconds at least.

6. Once you've pushed the lock button on all the remote keyfobs, they're programmed. You can then step out of the car and test all the remotes.

Before programming the remotes it would be a good idea to install a fresh CR2032 battery in each remote.

By the way, I found the best price on new uncut keys and remotes by ordering the keys and remotes separately from eBay sellers. At the time I was shopping, the complete units were $50 and up (some of them were used), but by purchasing uncut keys from one seller and the remotes from another, I was able to buy two complete sets for less than $80.00, and I think that included free shipping. I'm not sure if those deals still exist, but it would be worth doing a little research on eBay.

Cheers,

Don

 

Check out my article on programming key fobs, this artilce will give you a complete understanding of how the key fobs work and programming procedures and requirements for both the transponder portion (upper portion of key fob) and the key button portion (lower portion of key fob).

https://www.jaguarforums.com/forum/x...now-faq-87749/

Don's procedures will work to program the push button (lower) portion of the key fob but if you buy a new/used key fob and simply cut the key, the upper portion transponder still needs to be programmed. Usually you need two origional keys with working trasponders for your car to be able to program another on your own. With only one key, you will need to have the SDD program software or have a dealer do it unfortunately.

 

Thank you both for the detailed information.

According to your document, it looks like I'm going to end up going to the nearest dealer, which is 150 miles away, unless I decide to try an IDS software DYI project. I'm just paranoid having only one key with no backup in case it fails or I lose it.

 

I agree with you, having only one key fob is not a good idea. Invest in the IDS/SDD software, there is a lot of info on this forum on how to source it. It will come in handy for other things also. Using SDD to program a key is simple and will save you a trip to the dealer and avoid paying more than just buying the SDD software. I have programed the maximum 5 key fobs myself!

 

Sorry I forgot about the transponder! Thanks for setting me straight, lcmjaguar, and thanks again for your excellent article on the keyfobs and programming!

I also agree with lcmjaguar that investing in a Mongoose/SDD setup is a very small cost that will quickly pay for itself in DIY savings. With SDD I have programmed 4 keyfobs and performed lots of other valuable operations, such as reading all the Jaguar-specific DTCs, leveling and recalibrating the air suspension, disabling some of the irritating alarms, disabling the automatic application of the Electronic Park Brake (if it fails in the ON position you're in for some serious unhappiness), etc.

Cheers,

Don

 

A half decent locksmith will be able to clone the chip in your original key, if they can do that there is no need to program with SDD.

 

To add to the idea of key cloning.

Key cloning is where the locksmith uses a transponder programming device that can read your current key fobs transponder chip code and then use that to transfer that code to your new key fobs transponder chip, thus you have a second key fob cloned from the first original key fob. Usually what this means is that the car thinks you only have one transponder key fob rather than two as they are exactly the same. The car can accept up to 8 programmed transponder chips where each one is uniquely identified by the car. Through cloning, since you are making a clone you can theoretically have an unlimited number as the car thinks each one is in fact the original.

With that said, I am not sure that if one clones a key, that one can then use the car programming procedure of inserting two original keys to then program additional key transponders (without using SDD method) as the car may only recognize the two keys as just one key.

Any input from others on this?

 

Thanks again for the feedback.
It looks like a cloned key will serve my purpose for now.
I am the only driver (my wife prefers her SUV), so "his and her" keys are not really necessary at this point.