C4 Fob Programming

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Ramc4
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Re: Do you use lexia to program the key fob(remote)

Post by Ramc4 »

Paul-R wrote:
08 Nov 2019, 16:13
If I understand correctly I believe that locksmiths go down a different route and clone a key rather than pair a new one in. How they do that if there's no key at all I don't know.
You can use a lockpick like lishi to decode the lock and you also get handheld key cutters such as a1 pak a punch. So you can get in and also carry a range of transponders however you won't be able to program any keys without the security. However you can directly read the eeprom on the ecu by either soldering wires or using a clip and attaching this to laptop.

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GiveMeABreak
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Re: Do you use lexia to program the key fob(remote)

Post by GiveMeABreak »

Ramc4 wrote:
08 Nov 2019, 14:03
Just out of interest, would a pro locksmith ever attempt to decrypt the security code from the eeprom by dumping the memory while out on a job?

Say a mobile locksmith was called out and the customer had lost their there but badly needed the car, you can decode and cut a key on the spot but can't program without the code but you can decrypt the code from a memory dump. So would this just be too unorthodox a thing to do on a callout?
On some systems the code is encrypted and so not a matter of extracting it as it would be useless. Others 'clone' a key from working one. But in all cases new fobs / keys need to be coded to the vehicle using a suitable diagnostic tool. The code cannot normally be dumped from the BSI without first removing and connecting up to the BSI using special software and hardware - so no - that is unlikely to be the case. They are more likely to obtain the code after you provide them with the same identity check and ownership evidence that a dealer would request from you and then they can code a key with your confidential key.

Ramc4
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Re: C4 Fob Programming

Post by Ramc4 »

Will this lexia program keys in your opinion?

I messaged the seller with no replay for a day then decided to risk it and bought it now I get a message saying, 'sorry, do not the program function'.

I'll still try, what do you think?

Also. Know this won't be a full chip version but i thought even the basic lexia clones should still program keys?
https://www.ebay.co.uk/itm/Full-Chip-Le ... f321073784

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GiveMeABreak
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Re: C4 Fob Programming

Post by GiveMeABreak »

I'm not really sure what you are saying / asking?

Your problem will be with communication with some of the ECUs in full CAN vehicles. - it it cannot communicate with the correct ECU then it cannot perform a function.

If you are going to invest in an Actia clone, don't get a really cheap interface - there is no point if it doesn't work - and you may have worse problems on later vehicles....

Lexia (on your 2006 C4) or Diagbox for later vehicles 2008 onwards will be able to programme keys to the vehicle - but as I said, only if it can communicate with the BSI or other ECUs on your vehicle.

Ramc4
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Re: C4 Fob Programming

Post by Ramc4 »

Should be here Friday so I'll update you.

Ramc4
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Re: C4 Fob Programming

Post by Ramc4 »

Do you know where to find the key programming section in diagbox v.58?

I know in some versions you start off with a global scan then select bsi then i think select another option then key programming but the route to key programming differs depending on the version of diagbox?

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GiveMeABreak
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Re: C4 Fob Programming

Post by GiveMeABreak »

For your vehicle it is likely Diagbox will launch Lexia instead. Select your model and enter your RPO (build date code).

Once in, run a Global Test, then on completion, you will need to go to he top of the diagnosed ECUs, and select BSI and then validate. From there scroll down until you find the Programming menu, then select Key Programming.

The procedure is guided, follow the instructions.

Be aware, you must code all keys including any spares in the same session or those not included will be locked out.

You will also need your confidential code to proceed.

Ramc4
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Re: C4 Fob Programming

Post by Ramc4 »

Got it done.

Haven't been that nervous for a long time for some reason, was worried i'd brick the ECU.

I couldn't find the key programming section for ages and was about to give up before I finally found it, I think its under maintenance/replacement parts.

The £8 remote key i bought from eBay also worked including the remote considering Citroen wanted around £170 for this remote key....

Not sure I could have done it without the help from this forum, so thanks a lot.

I'm hoping to make a video of it all next week, I'll reprogram the keys in again for the video.

Cheers.