Fortwo 451 2009 Keys

[Mjolinor]

Looking for some concrete information as the Internet is full of can/can't will/wont.

My 2009 451 CDI only has one key. This has now bothered me for 8 years and I would like to do something about it.

Delphi has a key programme function but half the hits say it will not work. I am seriously worried about locking out my one working key so I don't have the bottle to try it.

WOW is also supposed to work but it will not talk to my DS-150.

Some Internet hits say if you buy an un-programmed key from China then the immobiliser chip needs programming somehow before the car will accept it. Some sites say you can programme a key from another car, some say you cannot. I have both Chinese electronics and couple of keys form a Smart that I broke for bits. not bothered which I use but would certainly like to have two keys.

I would also like to know what is involved if I do trash the one existing key when I try to programme another one. I am assuming SAM out and read the eproms or something nasty.

Can anyone give me some real world experience, not just a friends of my dogs mothers owner said ......

[gmb45]

fiitc........

[newone]

you can not use used key from anther 451,key must be virgin,china key will be fine,you just need a capable programmer to do the adapatation to car (old and new key),nothing has to be done prior the adapatation on new key

[rapidlocksmiths]

as stated above most good key programmers will code this in without issue , its a simple system even when all keys are lost , you must program the existing key again at same time as the new key .

[Mjolinor]

So basically the same as the 450?
I have done plenty of 450s but I thought the 451 was more difficult.

I aint a locksmith or mechanic any more, seriously retired so I don't have any key specific stuff but I do have Delphi and an old version of Xentry (abuot 10 years old with a C3 mux).

If these will not do it then what is a reasonable amount to pay a man with a van that does keys?

This bit aint really important but why does a used key not work? The car cannot write to the key so how does a used key look different to a new key as far as the car is concerned?

[rapidlocksmiths]

Because of the chip in the key , these use a pcf7941 intergrated id46 chip , all id46 chips are 1 time use and lock to the vehicle they are coded to exclusively , so cannot be used on another vehicle.

they can be reused as long as you buy a tool capable of unlocking and refreshing the key and restoring it back to its virgin new state , for a 1 off its cheaper to buy a new virgin key.

its different to 450 in that it has a pcf7941 intergrated chip which disarms the immobiliser rather than the remote doing this function, remote on the 451 is just for door locking and unlocking. process differs slightly but no more complex.

as to cost it differs from service to service , but to supply cut and program with guarantee i see prices between £140 and £180

[Mjolinor]

So when a new key is added to the car the key is actually programmed by the locksmith hardware?
The chip is write once, read many unless one has the specific unlock hardware?
I can simply replace the pcf7941 to make a used key blank again? That is easy enough.

It will not be possible to use either Delphi or Xentry to add a previously unused key?

Have the blades and new electronics so presumably under £100 should add another key?

[Mjolinor]

I downloaded the datasheet and a quick glance leads me to understand that the car can write to the key using BPLM. I did not expect that. Reading uses Manchester coding.

If the imobiliiser and door lock/unlock are separate in this key then maybe I should just glue the immobiliser part to the lock somewhere and programme another key to unlock the doors once I desolder its immo chip and remove it completely.

I only paid £170 for the car and it pains me to be looking at a similar amount to get two keys.

[rapidlocksmiths]

this thread may be of some help
https://www.digital-kaos.co.uk/forum...51-Programming

[Mjolinor]

Still a bit unclear here.

Does the pcf7941 control the immobiliser via the NFC coil and also control the lock/unlock via RF?
Or, does the pcf7941 just do the immobiliser and something else does the lock/unlock?

According to the datasheet it can do both but I can find nothing saying it does on the 451. The key has both an NFC coil and an antenna for (I guess) 433 MHz.

[newone]

if not wrong by change only 7941 will not work,it has to be precoded first,just buy a new china key (very cheap) and program it together with your old one

[Mjolinor]

if not wrong by change only 7941 will not work,it has to be precoded first,just buy a new china key (very cheap) and program it together with your old one

I don't think I have anything to programme it. I only have Delphi or an old Xentry.

[newone]

i do not have any of those,maybe some other member cun put some light,you can try to recode your original key,if you succed then buy a china key and program both together

[rob h]

Safest way, is to clone the present transponder. You will not have a remote function.
Xhorse mini keytool, and a superchip will do.


Some Chinese. offer a key cutting service. They only need a clear picture of the blade.


Or you order a remote key, from China, and look for someone in the area you live, to program it.

[Mjolinor]

Still not really making progress.

What is the cheapest thing I can buy that will absolutely definitely programme two keys to my Fortwo?