406 spare key. Does anyone really understand them?

I need another (third) spare 406 key, which I shall buy on eBay, and have
spent hours reading previous postings on this group about keys but still I
don't understand how to buy the correct one. Although it would be useful to
have another remote key I would be happy to settle for one that is not a
remote, it is only for back-up use. Does that make it easier to buy
correctly?

I have just bought a blank blade and that appears to be OK but the fob that
I purchased from someone else turns out to be the wrong kind. Like my
present key, it's the correct shape and has two similar buttons and no led,
but the blade is only 2mm thick when it should be 3mm. (I didn't know they
varied!)

Even the two key fobs supplied by the dealer for my 2001 reg 406 are quite
different shapes. One is fairly square in shape the other has a sloping top
but perhaps that is because only one is a remote.

These are some of the points I don't understand the relevance of, when
deciding what to buy:

Some blades are retained by a small screw, some are not. Does that matter?

I believe that infra-red has a led whilst radio frequency ones do not. Is
that correct in every case?

The 'spare' key supplied by my car dealer has no buttons and doesn't appear
to have access to a battery. Does this mean it doesn't have a transponder?
www.peugeotdeisel.com states that without a transponder the car will not
start. Mine starts OK. Can someone please explain that?

Are there any other hazards that I need to be aware of?

I realised this was going to be a minefield but I seem to be getting more
confused the further I get into it!

Can anyone please help?

 

My 1997 406 2 l will open using the spare key, however this model if fitted
with an IR transmitter rather than FM.

 

Hi Cire,
The info on that website is correct. Transponder chips do not require
battery power to work. In your solid key it will have a transponder
chip buried within the plastic. In the remote keys you will see the
small transponder chip normally sited in a closure near the key blade.
These transponder chips are energised by the hardware in your ignition
barrel when you place the key in.

Regards the type of key, there are numerous out there for the various
Peugeot models. You just have to ensure you get one that is
specifically for the 406.

 

Hi Cire,

The above is correct but the ECU will have to be programmed for the new key
because it will not recognise the transponder code in the key and will refuse
to start. The cost at a Pug stealership will be approx £70 to do this. I am
not 100% sure but I understand that the ECU can only handle 2 key transponder
codes anyway. Hope this helps.

DaveG

 

Yes, I forgot to mention the programming of the transponder but it is
the transponder chip that is programmed, not the ECU.
Only time the ECU has to be reprogrammed is if all keys and the
security card were lost.

 

Thanks for some interesting points, folks, but I still have more questions
than answers!

I don't quite understand how one ensures this when most keys I see
advertised say 'for 206, 306, 406' or 'may fit other Peugeots'.

Yes, I forgot to mention the programming of the transponder but it is
the transponder chip that is programmed, not the ECU.
Only time the ECU has to be reprogrammed is if all keys and the
security card were lost.

 

Hi Cire,

The chances are that these keys will not work as it is very unlikely that the
transponder code will be the same as one of your original keys. I am not
saying that daddyfreddie is wrong but I was informed by local stealership
that a code can not be programmed into the transponder, it is the ECU that
needs to be programmed to match the key but they could be wrong !

Regards Dave G

 

Hi Dave.

It is all beginning to look as I suspected - Peugeot have us by the short
and curlies !

Thanks. Eric