Hey everybody!

This is my first post as I just proudly purchased a used 04 Crossfire Awesome car! Now, it came with a pretty worn down key which just doesn't look too good, but also with a replacement key, which doesn't work. Changed the batteries already and still won't work so it has to be the programming. Went ahead and tried the "Turn key in ignition and hit the lock button twice, then turn" instructions from the forum here but even that would not program the key.
What else can I do? How do I replace that chip inside of the key, lets say from the working key into the spare key?
Thanks for any suggestions and hope you all have a nice weekend --

Nick

 

There is a thread here somewhere on re jigging the key and fob, but is there a chance that the spare you have is actually the correct spare?
Maybe the previous owner purchased a spare and found out it could not be modified.
If you mess up the key that works you'll be left without a car and have to spend $150 for a new one.

 

Yeh it's weird, I don't know what the matter is with that key. Looks just like the original and has the same serial number on it. Couldn't get it to work though...I assume it's kind of hard to take the key apart and put the chip in the "clean case".

 

Try these.
https://www.crossfireforum.org/forum...tml#post185072
https://www.crossfireforum.org/forum...estroying.html

 

Spare keys have to be individually laser cut to the VIN, and you can test that by unlocking/locking the driver door manually. If that works, do a search on the forum for setting up a new key. It's a 3-4 step process and very easy. I believe if it turns the ignition and the car does not start, they key has to be set up as I mentioned above.

 

Seemingly the key turned in the ignition so I guess it will fit the doors.
The keys are not laser cut, they are machined.

 

Hopefully you tried "programming" more than once ..... sometimes it take several tries...Just sayin ...

 

I'm going to go and try it again. It is weird, pretty sure it is the original spare key that came with the car but for some reason it won't work. It fits the door lock and ignition but just won't turn...I don't know, weird!

 

If your other key turns both the door and ignition locks, but this one does not, then it is not the key for the car. Whether the fob is programmed or not, a matching key will turn the mechanical locks. So either it was cut wrong or someone got hold of a used key and "hoped" it would work. If both operate the mechanical locks, then programming it should work. You may have to replace the internal fob battery for the programming to work.

Not laser cut - ok. Maybe I am thinking of my Audi keys, which somewhere I read were laser cut and look almost identical to the XF keys. The Germans seem to like switchblade key fobs.

 

Hate to sound like a jerk but did you replace the batteries. I was in O'Rielly's the other day getting some plugs for the TR6 and noticed they had a key fob tester on the counter. It tested the batteries. Might be worth a shot.

The keys have a micro chip inside that is programmed with your vin. If it came from Ebay or another car the spare you have is useless. It CAN NOT be reprogramed or setup like a new key.

Dealer is best place to get a replacement. Cost is about $130. It comes from Mercedes out of Fort Worth area. You will need your registration/title and a picture ID at most dealers before they will oeder one. Oh you will also need to bring the complete VIN. Make sure it is correct or you bought a useless key. NO EXCHANGES or RETURNS. You prepay for the key.

 

Beg to differ. The VIN is required to get the key properly cut. It is programmed by mating it up with the sensor in your car using the little process on this forum. Agree that the battery can be dead -- they don't last forever and if you leave them in the proximity of the ignition they "chat" and the battery in the fob drains faster.

 

Beg to differ.
If the VIN is required just to get the key cut then it would be possible to take any key, machine it to fit and then program it. Where is the security in that?
The VIN will be required to match a code that is registered to your car and only your car. Any use of that key except unlocking it will depend on that code matching the one stored in your cars system.
If the key does not turn then it is the wrong key, which has the wrong encrypted code, or unlikely it is the OEM fob but all the locks have been changed which only match one key.
I am sure they do not chat to one another or they would be chatting all the time you are driving.
The op stated that he has already changed the batteries in his first post.
My conclusion on the facts as stated, wrong fob.

 

Sorry I did miss he had changed batteries BUT seeing if it is working after the battery change is still not a bad idea and it was FREE. I think I'd try that before spending $130 plus on a new one..

 

Hey everybody... I've got a very similar issue. I've got a 2006 & it came with everything, 2 keys & a Valet key, all original & working. The issue I have is the second key that I put in a drawer had the batteries run down. I know the key worked.

Problem I have now is that the one in the drawer (un-molested...) now won't operate the remote entry. I've paired it up by the 2 step process (repeatedly). It works in the door & in the ignition to start the car, but no luck with remote entry. The molested key (Kids... Argh!) still works, but would rather switch to the "nice" key/fob.

So anyone know what I'm doing wrong? Repeat: The key starts the car, so it must be paired up with the chip. I've swapped batteries with really really fresh batteries (thought the ones I bought a few months ago may have been stale).

Thanks!

 

I just read you post and please clarify for me at least. When the car was new to you DID the remote entry work using the spare key or did you just test it by starting the car. The reason I am asking is that they are two different systems in the car. Thanks.

 

Yep, when the car was new both keys/fobs worked for the car. Now after a few years the second key (spare) won't work the door locks. It works in the ignition to start the car, but not the doors.

 

This may sound dumb but I do not mean it to be insulting. Go to a auto parts store and have the transmitter check. You hold it within a couple of inches and press. If the light goes on their instrument it is transmitting. If not check that the batteries are in correctly. Any dealer also can check this.

Another thought the key and lock work off the CAN bus via the chip in the key which is tied to the VIN and the automatic lock/unlock uses an automatic transmitter which then signals the CAN bus. IF one key works and the other does not it has to be the batteries OR the transmitter in the key. If the batteries are OK then the only solution is a NEW key. They run about $130 from the dealer. You will need VIN and proof of ownership before they will order one.

One other thought watch where you stored the spare. It can be damaged if in a junk draw. I keep mine in my night stand draw.

 

No harm done... the board on in the FOB doesn't have power... The trick to switch to single/double push to open the doors clued me in. I held both buttons down & couldn't get the light to light up. I may just switch the chassis between the good/bad key. Not sure if I want to risk hosing up the one that is still working. Thanks for the advise!

 

sounds like you just need a programming for your keyfob to car.
and or battery, yes.

 

1) Why are you responding to a two year old thread?

2) This is not programming, this is what happens when the battery in the FOB is dead - the key's passive encoder will start the car, but with a dead battery, there is no power for the remote transmitter.