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@stevesmiff don't know if you resolved your problem, but you maybe in a similar boat to me on a 57 plate 1.5 scenic dCi.
One of the pair of key cards started coming up with Card Not Detected recently...the other fine so clearly the reader was OK. These are MK 2 Scenic 3 button keys with a chip marked as PCF7947AT among the 3 buttons on the pcb
The bad one would work to start car if I put it in reader and put pressure on from one side...took this just to be a variation on the well documented (you tube) knife trick and suggestive that contacts on the coil had become detached.
It seemed to be getting worse so opened the key card - sure enough one of the 2 contacts on one side was detached as was the lone one on the other side. Now on the lone one, there are no obvious contacts so I've taken that to there be just for support.
Re-soldered the other and have a good joint.
On putting back together , I get nothing - wont open the doors or be detected in the reader.

Looking over the PCB, it looks like on opening the card, I've dislodged a couple of other component..
1 is still connected on one side but clearly loose, another has come off completely (but I have it - its no bigger than an ants willy though) and there may be a third missing altogether. Given the pic below can anyone tell me how many I'm missing - if any more than 1 any attempt at further repair will fail...cos ill have lost any more than 1.
The ones I know were dislodged were those (resistors ?) bottom left. Left of 5100 chip...can anyone tell me if I'm missing 1 or 2 - I don't want to take the other apart and risk losing that one as well...
187474
 

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@teejaybee I'm afraid my issue was never resolved. Running off the one working key and hope I never need my spare!

Attached a pic of my non working key. Shows a fully loaded set of resistors (or whatever they are) next to that chip. Thing is, my key is for an 04 Megane II so prob different layout. Also spotted yours has one top right (above transponder) and mine doesn't. Once again could be different models or possibly why my key isn't working? I'm pretty sure I didn't damage my key when opening so my problem still a mystery???
187480
 

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Very grateful for the reply..though of course it confirms that I've lost one of those components, so I'll also be going forward with just the one key card, unless I can find someone willing to sort a new one for much less than the renault fee.
 

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Related to the above, I purchased a blank key card from youknowwhere, its described as a 3 button remote for 2003-2009 scenic, but has very different circuitry within. The nice thing is that the card itself can be opened and closed multiple times.
I don't know if the electrics have been updated and this (given the right programming) will do the job...
And I'm still a bit lost as to whether I need to have a circuit that is programmed to my VIN specifically to get it to work as both door lock/unlock and car start/stop...
It does seem as though I need to program the immobiliser (?) to accept this key (if indeed it is the same as the old in function)...
Can anyone summarise? Think I've read some saying that since 200x its not been possible to do anything with a blank until its had the VIN programmed in France...others saying not so.
 

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Can't offer much on the specific but the general details are.
The key fob has a single circuit that performs two things.
1st is the immobiliser part. This is a passive unit (RFID) that needs no power, it is simply a code that the reader in the card slot reads, then the vehicle systems say ok to start or not.
2nd is the remote lock/unlock. A radio transmitter that fires a coded signal to the vehicle receiver and if the vehicle likes the code, it does what it is asked. The key fob battery powers this function.

Both can be coded to a suitable key by anyone with the right kit and knowledge.
Usually copied from the other key
Google Autolocksmith and where you live to find one.
Renault do not do this unless they have changed their systems. Normally if someone requires a spare key, they supply a copy of the one originally supplied.
 

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Can't offer much on the specific but the general details are.
The key fob has a single circuit that performs two things.
1st is the immobiliser part. This is a passive unit (RFID) that needs no power, it is simply a code that the reader in the card slot reads, then the vehicle systems say ok to start or not.
2nd is the remote lock/unlock. A radio transmitter that fires a coded signal to the vehicle receiver and if the vehicle likes the code, it does what it is asked. The key fob battery powers this function.

Both can be coded to a suitable key by anyone with the right kit and knowledge.
Usually copied from the other key
Google Autolocksmith and where you live to find one.
Renault do not do this unless they have changed their systems. Normally if someone requires a spare key, they supply a copy of the one originally supplied.
Appreciate you taking the time to reply thanks.
 

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@teejaybee I'm afraid my issue was never resolved. Running off the one working key and hope I never need my spare!

Attached a pic of my non working key. Shows a fully loaded set of resistors (or whatever they are) next to that chip. Thing is, my key is for an 04 Megane II so prob different layout. Also spotted yours has one top right (above transponder) and mine doesn't. Once again could be different models or possibly why my key isn't working? I'm pretty sure I didn't damage my key when opening so my problem still a mystery??? View attachment 187480
You might be interested to know that I’ve had mine repaired by a guy on eBay for £16 plus a few expenses...
I sent the PCB plus a resealable case (also off ebay) and battery to him on basis it was worth a try at that price - had it back 2 days ago and all is working.
@teejaybee I'm afraid my issue was never resolved. Running off the one working key and hope I never need my spare!

Attached a pic of my non working key. Shows a fully loaded set of resistors (or whatever they are) next to that chip. Thing is, my key is for an 04 Megane II so prob different layout. Also spotted yours has one top right (above transponder) and mine doesn't. Once again could be different models or possibly why my key isn't working? I'm pretty sure I didn't damage my key when opening so my problem still a mystery??? View attachment 187480
Mine is now working fully thanks to an ebayer, whose repaired it (£16 plus expenses). I sent the PCB plus resealable case (also off eBay) and battery in. Had it returned in a week.Excellent job...
seems to good to be true.
 

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You might be interested to know that I’ve had mine repaired by a guy on eBay for £16 plus a few expenses...
I sent the PCB plus a resealable case (also off ebay) and battery to him on basis it was worth a try at that price - had it back 2 days ago and all is working.

Mine is now working fully thanks to an ebayer, whose repaired it (£16 plus expenses). I sent the PCB plus resealable case (also off eBay) and battery in. Had it returned in a week.Excellent job...
seems to good to be true.
Deleted... !
(Wasn't an advert as I gave NO information, just commenting on the cost - Above IS an advert tho!)

Ian...this is advertising and is against Forum Rules, be warned, won't be so tolerant next time
 

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Hi guys, so I just got Megane 3. I got two cards, guy that sold me car, said to me that spare card is never used, and that need to be authorized?, I tried using it, it doesnt unlock car, but I can start car with it normally, it does look new, so I dont know..
 

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Hy everyone!

Long time no see :)

I already have one Med Mk2 1.5 dci on my garage and I've decided to buy another one to retire the "old" on, but it only have 1 key, its a hands free version but I only have 1 key. I've been away from this and I've decided to catch up because now I need to clone my working keycard to another handsfree keycard but to do that I'll need your inputs, I think you guys are more aware of things than me.

So far I've managed to understand that i need to PRECODE the card with Zed-bull (or other tool - which I don't have). To do that I'll need the PIN code for the car and only in the end, after PRECODING the card, the virgin card can be PROGRAMMED with the car. In the process I've to be very carefull because I'll be only able to do it once, the PCF7943 (inside the virgin card) only accepts one writing, no space for failures.So do you guys know some tutorial with info on how to do this?

Right now this is not urgent but it can be, I've recovered two keycards in the past and posted how to do it here 10 years ago, and during this time I've never needed the 2nd card - thank God :) For this "new" car I want to have the 2nd card available, just in case.

Thanks everyone for the inputs
 

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Hy everyone!

Long time no see :)

I already have one Med Mk2 1.5 dci on my garage and I've decided to buy another one to retire the "old" on, but it only have 1 key, its a hands free version but I only have 1 key. I've been away from this and I've decided to catch up because now I need to clone my working keycard to another handsfree keycard but to do that I'll need your inputs, I think you guys are more aware of things than me.

So far I've managed to understand that i need to PRECODE the card with Zed-bull (or other tool - which I don't have). To do that I'll need the PIN code for the car and only in the end, after PRECODING the card, the virgin card can be PROGRAMMED with the car. In the process I've to be very carefull because I'll be only able to do it once, the PCF7943 (inside the virgin card) only accepts one writing, no space for failures.So do you guys know some tutorial with info on how to do this?

Right now this is not urgent but it can be, I've recovered two keycards in the past and posted how to do it here 10 years ago, and during this time I've never needed the 2nd card - thank God :) For this "new" car I want to have the 2nd card available, just in case.

Thanks everyone for the inputs
PRECODE just sets the card to the model of car, you then need to add the key via OBD2 tool.
A good OBD2 tool will get the PIN code for you, read from the body control module.
If you buy a complete keycard it will not need PRECODING, just add the key with your OBD2 tool.
If you make the key by adding a new PCF7947 chip then you need to PRECODE it.
If you have a PCF7943 key then you need an expensive OBD2 tool to add the key as most tools don't support it.
Hope this helps

Regards
 

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51 plate Laguna 2 1.6
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Hi guys, so I just got Megane 3. I got two cards, guy that sold me car, said to me that spare card is never used, and that need to be authorized?, I tried using it, it doesnt unlock car, but I can start car with it normally, it does look new, so I dont know..
The central locking switches may be broken or it may need synching to the car. Have a search on the forum for advice.
 

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PRECODE just sets the card to the model of car, you then need to add the key via OBD2 tool.
A good OBD2 tool will get the PIN code for you, read from the body control module.
If you buy a complete keycard it will not need PRECODING, just add the key with your OBD2 tool.
If you make the key by adding a new PCF7947 chip then you need to PRECODE it.
If you have a PCF7943 key then you need an expensive OBD2 tool to add the key as most tools don't support it.
Hope this helps

Regards
Hello IanMorris,

Thanks for your help.

"If you buy a complete keycard it will not need PRECODING, just add the key with your OBD2 tool." - You mean buy it from a Renault dealer? The only way I know to get a precoded key is to buy it from the dealer, or there is other options?

For adding the key to the PCF7943 or PCF7947 it must be done with a proper tool, like the Zed-bull I've mentioned, or am I missing something? Only after the programming can be done with the OBD2 tool

Thanks
 

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Hello IanMorris,

Thanks for your help.

"If you buy a complete keycard it will not need PRECODING, just add the key with your OBD2 tool." - You mean buy it from a Renault dealer? The only way I know to get a precoded key is to buy it from the dealer, or there is other options?

For adding the key to the PCF7943 or PCF7947 it must be done with a proper tool, like the Zed-bull I've mentioned, or am I missing something? Only after the programming can be done with the OBD2 tool

Thanks
Even fake keys are PRECODED, you only need to PRECODE if you physically change the PCF7947 chip on the PCB.
ZebBull is the tool for PROCODING the chip on the PCB.
You can't PRECODE a PCF7943 as it doesn' work.
I hope this explains it for you :)

Regards
 

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Even fake keys are PRECODED, you only need to PRECODE if you physically change the PCF7947 chip on the PCB.
ZebBull is the tool for PROCODING the chip on the PCB.
You can't PRECODE a PCF7943 as it doesn' work.
I hope this explains it for you :)

Regards
Hy Ian

From what I've been reading around the web it's possible to code the PCF7943 but the difficult part is to get one virgin, without any previous usage or not fake (some are marked as PCF7943 and in fact they're not).

If we're lucky to find one of those chips (or keycard with the chip pre-installed) the card can be precoded with Zed-bull, Tango or other, and after that it can be paired with the car.

I'm not very familiar with buying chips from the web, from Aliexpress is a matter of luck, and the same for other chinese stores. If there was a reliable place that sells those chips it would be worth a try,
 

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Hy Ian

From what I've been reading around the web it's possible to code the PCF7943 but the difficult part is to get one virgin, without any previous usage or not fake (some are marked as PCF7943 and in fact they're not).

If we're lucky to find one of those chips (or keycard with the chip pre-installed) the card can be precoded with Zed-bull, Tango or other, and after that it can be paired with the car.

I'm not very familiar with buying chips from the web, from Aliexpress is a matter of luck, and the same for other chinese stores. If there was a reliable place that sells those chips it would be worth a try,
The only difference between PCF7943 and PCF7947 is the Proximity function. (and the amount of legs)
Your car can be programmed with both, so if proximity isn't a priority then just use PCF7947 cards.
All Chinese PCF7943 chips are fake and can't be precoded so you'd need to buy direct from the manufacturer,
this makes it uneconomical to repair the card as the chip is more expensive then a new card.
Messing with ZedBull is a thing of the past, we just use PCF7947 cards now as it's much easier.

Regards
 

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Hy Ian,

Thanks for your inputs. Well, this is just a 2nd emergency card so the 7947 should work just fine for that.

When I'm going to program it for the car I'll need to program the new card and the old one again. I'll not loose the proximity sensor for the old one?

What about the new card, it cames precoded to the car. How is that possible? I have to tell the seller some info about my car?

BR
 
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