Replacement keys

[cesbh92]

Hi folks
sorry if this has been covered before but I have tried to search for an answer and can not find the info I need
I have recently purchased a 2002 2.0 diesel 110 estate and was only given one key the previous owner claimed to have mislaid the other one when it was traded in what I need to know is if I get a key fob from ebay and get a new blade cut can the key be reprogrammed without taking it to a main dealer.
any help will be appreciated thanks Cliff

[lozz]

Hello,

you mean Secound hand key fob off ebay?

if so idont think they can be re-programmed so you might end up taking gamble,
just get a basic key cut,

[oldcol]

I don't think so. But you can get a Transponder key (ie Chipped but with no remote facility) made by Timpsons which is an ideal spare. Opens the car manually and starts the engine. Timpsons prices seem to vary from branch to branch but i got my from their Lowestoft branch for 25 quid and it works perfectly. Incidentally my local Pug dealer still maintains that they can only be got from a Peugeot dealer ~ Rubbish. With my particular branch you program the chip yourself ~ they sellotape a new chip to the plastic fob of your existing key. Go back to your car and open the doors with your own key MANUALLY (Don't use the remote facility !). Insert your key with it's piggy backed chip into the ignition barrel and turn it 2 clicks so the warning lights etc come up but BEFORE the starter operates. Count steadily to 10 then turn off. Without removing the key, do this 3 more times and then remove the key and go back to the store. They check that the new chip has coded correctly then cut you a new blade and then the blade and newly coded chip are installed in a new plastic fob and job done. £25 as opposed to about 80 from your Pug dealer !

[rwb]

This is a good question, and I want to find the answer.

A treatise on the theory of keys.

Definition 1
There are two official processes that can be performed with keys. They are:
(a) the one where you put the key in and hold the button, and
(b) the one with PP2000 where you need the secret code.

There appear to be two possibilities for what these processes actually do:
(i) to read from the BSI and store to the key, and
(ii) to read from the key and store to the BSI.

Definition 2 (key function)
There are three functions of the key:
(a) to lock and unlock the car remotely by pressing the buttons;
(b) to lock and unlock the car using the key blade ,and to turn the ignition barrel; and
(c) to disarm the immobiliser by having the chip read by the aerial that lives around the ignition barrel.

Conjecture 3
Operating the ignition three times with a piggy-backed blank chip is equivalent to Definition 1(b).

Proof. What oldcol said.

Theorem 4 (key programming)
When making a new key one must:
(a) perform Definition 1(a) to enable Definition 2(a),
(b) get the key blade cut to enable Definition 2 (b), and
(c) perform Definition 1(b) to enable Definition 2(c).

Proof. Follows from correspondence of parts (a) and (b) of Definition 1 with parts (a) and (c) (respectively) of Theorem 2, and the correspondence of Definition 2(c) with Definition 1(b).

If Conjecture 3 is true then it may be applied to prove Theorem 4(c) as an alternative to Definition 1(b).

Conjecture 5 (fly in ointment)
Chips cannot be re-programmed.

Conjecture 6 (answer)
Any existing key fob can be used on any car by installing a new chip then applying the Key Progamming Theorem (Theorem 4), and getting a new blade cut.

Proof. Follows immediately from the key programming theorem (Theorem 4) and Cojnecture 5.





Discuss
Seriously, that took a while to formulate and I'd appreciate any effort to understand it and comment because it would be really cool to outwit Peugeot on this one and I really want to find the answer.

[Doggy]

Wot I reckons.....

Key /fob has 3 components:

Metal blade - purely mechanical / copyable, fits or it doesn't

Transponder chip - can only be programmed once, matched with the immobiliser. Always generates the same code, (which I think is matched with a number stored in the engine ecu, separately to map file area). Short version, you can't change it.

Remote plip - can only be programmed once, matched with codes stored in the BSI. Generates a different code every time, but based on a fixed 'seed' number, the sequence is predicatable, therefore the BSI can differentiate between valid and invalid keys. If the key is operated several times out of range of the car, synchronisation can be lost and recovered using the synch procedure in the handbook. I managed to lose mine completely by removing the car battery without following the rules.....
The BSI is capable of learning / relearning keys - up to 5 of them IIRC, you need to use this method if re-synching doesn't work.

Does the re-learning process also affect the immobilser? I don't know, as I have only ever got a car to re-learn its own keys. Anyone know for certain?

[C15GrandVolume]

I would like to learn a new key to the BSI on my 1999 Hdi (RHZ). I do have the access code, but the problem is that this access code has letters and numbers. But in PP2000 I can oly enter four numbers. Do I need another version of PP2000?
Also I have tried to match a used 1 key RF remote, but without success. Maybe it is possible to write a 'virgin' file to the chip on the circuit board? I reckon it won't help to copy the file of the remote that was already with the car (and working) to the 'new' used one because it generates a new code everytime and needs to be in sync with the BSI...