programing a key

[wheeler]

Assuming the new transponder chip is actually new & virgin then if you can re program the original key but not the new one then the chances are you have a faulty transponder aerial. The aerial has 2 coils inside it, a reader coil & a writer coil. as we know once a chip has been programed to a car it cant be re programed again to a different car, when you 'delete' a key with lexia you dont actually erase it, the car just ignores it if you like, when you 're program' a key back to the same car all it does is accept it back in again so it doesent actually write anything to the chip as its already written. When you program a virgin chip to a car the aerial 'writes' information onto the chip. So if the writer coil is knackered the car wont be able to program a virgin chip but can reprogram keys that were previously programmed to that same car.
If you know someone with the same car you can borrow thier aerial to do the programing then swap it back afterwards. Alternativley the aerials are not that expensive.
Ive never seen this problem on a C3 but very common on picassos, i keep a spare new aerial for the picasso for this excact scenario.

[deano1970]

Indeed, I am with ben, and you have answered your own question with the post from the locksmith, maybe you found that on my post,I posted it after buying a fob mylesf, only to find out that they can NEVER be reprogrammed to another car once the have been programmed to a car....the only thing these are good for is if you need the case, the internal workings have been assigned and the chip has been imprinted with info on that car and it cannot be changed...I found this to my cost(only 9 quid but hey)....problem is lots of e bay sellers just state that blade needs changing and reprogramming,which is false,as It cannot be done on your car......I think xantias have been programmed successfully with old remotes but not newer cars, also,from looking at some feedback, other cars have been reprogrammed successfully as well,but don't bother with a citroen one, wasting your money i'm afraid.....

[crazybear_uk]

No found it on ebay last night. snap cost me £17.00 (10 + 7 key cutting) O well at least I got to play with lexia and clear some faults with it at same time and got my pin code which is correct just need a new fob now

[deano1970]

oh well,you live and learn eh?? I have been quoted £120-140....which is expensive, but half the price citroen quoted me.....I mailed the main dealer to ask why It was so ridiculously expensive, needless to say, they didn't write back after their original quote.......shame they can't be reprogrammed really.I didn't have a key cut, I just wanted the fob to lock and unlock the doors as I was having trouble with the freezing weather. Oh well, I will get one before next winter

[jjsmith1100]

just found this
CITROEN REMOTES. AIMING TO HELP YOU SAVE MONEY! FACT!

I am a vehicle locksmith and key programmer of 12 years experience. I have been selling and programming keys for these 12 years. Over the past few years remote selling on Ebay is high. This review is to tell people all is not what it seems. The information below is for Citroen cars. I have been a little fed up with the people coming to me after being charged by a dealer for programming key even though they have failed because second hand remotes cannot be programmed to most cars. So here goes to assist you.

This remote is on Citroen C1, C2, C3, Xsara Picasso and Berlingo.

I must tell you that on Citroen Xsara Picasso & Citroen Berlingo from 1999-2002 have a differant remote but have been superceeded to this remote above. The below information is for these cars too.

This remote is a one car programming remote. From the first day it is sold it starts off its life virgin. As soon as you program the remote it changes the chip to imprint the cars information too it. This way the remote now can only be reprogrammed to the same car. ONLY buy this remote if it is brand new in a parts bag. Many advertise this remote as new with a new key blade. DON'T be fooled. The condition is new but it has already been programmed. Please make sure it has not been programmed to another car.
Also beware each model has a differant remote and part number even though they look the same. Even if you find a new one make sure the part number matches the part number you get from your dealership to your chassis number. No remote works each other.
This remote is on Newer C2, C3 also on C4, C4 Picasso and C5 facelift.
The information for this remote is exact to what is writtern above. DO NOT buy unless it is brand new. All dealerships will only order these cut already to a car. So sometimes you can fins a new remote already cut but again make sure it has not been programmed before. Also make sure the car it came off as again they don't work each other model.
My advice is buy this from a locksmith or dealership.

DO NOT EVER buy these remotes off Ebay. These remotes can only be bought in the first place cut to the car intended then programmed. They cannot be reprogrammed and a new blade is not possible to be fitted. Please again DO NOT BUY.
Hope this has all helped.
Thanks
ddkeyprogrammers

I know this has been nearly a decade now, but I would like to know. I have a C2 with a chip not on the remote board. I lost the original chip and it was replaced, but since then the remote no longer works, although it was working just fine before even with the chip missing. All the synch procedures has no effect. Any advise on how to get it working. Unfortunately I only had one key to start off with. The remote board is still the original I got with the car.

[GiveMeABreak]

If you've replaced the actual chip, then synchronising won't help - the chip first needs programming using a Diagbox / Lexia diagnostic tool or other suitable diagnostic system to programme all the keys that will ever be used in the same session. Re-synchronisation can be undertaken at a later date if needed (like when the rolling codes have been exhausted) or a battery disconnection has taken place, but not until a new chip has first been programmed. Chips can only be programmed once.

So you can't simply synchronise an up-programmed chip.