Citroen key/fobs - Programming

[c16rkc]

I have searched the forum for information on fob programming, but I only seem to be able to find information on older models like 00's era cars. I wonder if anyone knows about the newer cars?

I have a 2008 C5 X7, and it came with just one key/alarm fob. I can get a replacement key cut easily, but I can't seem to find if a good used fob can be programmed to work with my car.

Does anyone know if I can do this?

[Hell Razor5543]

Used fobs, once they have been 'paired' to a vehicle, can only be used with that vehicle. In effect, they can only be 'written' to once.

When you get a new key you MUST 'introduce' ALL keys to the vehicle. If you don't, any that were not done at that session will be 'forgotten' by the vehicle. Fortunately, if you then find such a key, you can 're-introduce' it to the vehicle and it will be remembered again (just make sure to do ALL of the keys again at that session). So long as the 'missed' fob had been 'introduced' to the vehicle (when the fob was blank) it will work.

[GiveMeABreak]

Same procedure applies Chris, nothing has changed.

[GiveMeABreak]

Same procedure applies re programming Chris, nothing has changed, but as said you can't use a 'used' fob.

PS: Thanks for your Forum donation. Any part numbers you need for your PSA vehicles, please request them here:

viewtopic.php?t=69962

[c16rkc]

Ah what a pain... so why on earth do people sell used fobs on Ebay? - It would seem they are useless unless you own the car they came off.

So is the only option to buy a brand new fob?

I confess I never noticed in the instructions for older C5 models that the fobs had to be brand new, I got the impression you could program a used fob to a different car (or should I say program the car to recognise a used fob from another car).

[c16rkc]

PS: Thanks for your Forum donation. Any part numbers you need for your PSA vehicles, please request them here:

viewtopic.php?t=69962

No worries, the people on this forum are awesome

I'm very pleased to have joined the Citroen elite; I should have done it when I bought the C3!

[Hell Razor5543]

You will also need the security card that the car came when new. Certain functions (such as key programming) need to be 'unlocked' to allow access, and the four digit code does this. If you do not have the code you should be able to get it from Citroen (with proof of ID and ownership of the vehicle),and they may charge a fee for this.

[GiveMeABreak]

Ah what a pain... so why on earth do people sell used fobs on Ebay? - It would seem they are useless unless you own the car they came off.

So is the only option to buy a brand new fob?

I confess I never noticed in the instructions for older C5 models that the fobs had to be brand new, I got the impression you could program a used fob to a different car (or should I say program the car to recognise a used fob from another car).

This may be because they are part of a set (Fob, BSI & Engine ECU) for the reason once paired they are a matched set. Or, they are scamming people!

It's been the same procedure for PSA vehicle for as long as I can remember Chris. People may want to go to the trouble of unsoldering a transponder ID chip and replacing it, which may work, but my soldering skills and patience fall far short...

You can order an original fob from the dealer, or you can buy these cheaper elsewhere online - but I'd use a more reputable seller than the cheap things offered for a few quid that won't likely have the internal circuitry for the remote locking and third button functionality.

[c16rkc]

You will also need the security card that the car came when new. Certain functions (such as key programming) need to be 'unlocked' to allow access, and the four digit code does this. If you do not have the code you should be able to get it from Citroen (with proof of ID and ownership of the vehicle),and they may charge a fee for this.

Wow what a faff; I used to be able to buy a second hand Jaguar fob and program it to the car within minutes - I confess Audi/BMW/Mercedes fobs are just as much of a pain though...

If nothing else, I was hoping my special magic Alexa Citroen software with Opto-couplers was going to be able to do it...

I'll have to source some brand new fobs then ...and I'll have to see if the security card is in the owners wallet/bookpack that came with the car.

[c16rkc]

Ah what a pain... so why on earth do people sell used fobs on Ebay? - It would seem they are useless unless you own the car they came off.

So is the only option to buy a brand new fob?

I confess I never noticed in the instructions for older C5 models that the fobs had to be brand new, I got the impression you could program a used fob to a different car (or should I say program the car to recognise a used fob from another car).

This may be because they are part of a set (Fob, BSI & Engine ECU) for the reason once paired they are a matched set. Or, they are scamming people!

It's been the same procedure for PSA vehicle for as long as I can remember Chris. People may want to go to the trouble of unsoldering a transponder ID chip and replacing it, which may work, but my soldering skills and patience fall far short...

You can order an original fob from the dealer, or you can buy these cheaper elsewhere online - but I'd use a more reputable seller than the cheap things offered for a few quid that won't likely have the internal circuitry for the remote locking and third button functionality.

Thanks Marc, I may well have to speak to the parts counter at the Peterborough dealer, and see how many of my fingers they want for a genuine brand new fob...

[Hell Razor5543]

Only an arm, a leg and (if they are feeling really greedy) first proof that your DNA is genetically viable!

[c16rkc]

I might need the arm to program the fob, so I guess it will be a leg then....

[wheeler]

Ah what a pain... so why on earth do people sell used fobs on Ebay? - It would seem they are useless unless you own the car they came off.

Some types of chips can be re written over & over again, like you old Jag. Many old Fords/Jags use 4D type chips that can be re written to as many different cars as you like. Also many different PSA remotes with the right kit can be re flashed to unlock them meaning they can be re used. Not worth buying the kit just to do one car though.

A new key from Citroen is around £160 (uncut) or £187 (pre cut to code). Thats including VAT just for the part.
I bet most auto locksmiths would be able to supply & program a new one for under £190 and a good auto locksmith will be able to pull the code from the car without needing the code off the dealer either.

[c16rkc]

Thanks - that's very helpful.

I have done a bit more research, and it seems I am treating two subjects as one;

1) The unlock/lock alarm fob PCB.
2) The key/transponder which starts the car.

If I understand correctly, the unlock/lock fob can indeed be reused and the following sequence will setup the fob to unlock/lock the car. As far as I can tell you can also use a "used" fob for this purpose, and this may be why the used one's on Ebay have at least some use.

However the transponders seem to be "single use" and these need to be assigned to the car using the special Lexina the goddess of Citroen software and cable with opto-couplers and flux capacitors. I understand that generally speaking these are single use, and once setup to a car they cannot be re-used on a different car.

So I am tempted to buy a £15 used fob from Ebay, and a brand new transponder for a few quid (you can get them on Ebay and Aliexpress) and try my luck. I found an excellent Aliexpress supplier who cuts a key from a photograph; they key they cut for me works better than the original that came with the car, and it came with a nice case.

The only issue is I have not quite yet worked out exactly which transponder is right for my car...

I am hoping I have all that right...

[wheeler]

No, on this car the remote & transponder are programmed together at the same time. If you put a blank transponder in it then it will program & start the car but the remote won’t work. A used one wont program to the car unless it is re flashed first with the right kit.
I don’t know why you would buy a used one for £15 when you can get brand new aftermarket for less.