New car key

Tony Danza

What are your views on the following,

I'm thinking of buying a car key on e-bay, there's loads of the right one's for my car there. But it will already be programmed, so was going to buy a programming key guide (and re-program the key to suit my car), also off e-bay and try to program it myself. Which leaves me with needing a new blade, guess where I can buy one of them, which means all I'll need is to get a locksmith to cut the blade. A total cost of under €40.

Can somebody see a flaw with my plan before I buy anything? I heard that if you put in a key with the wrong transponder chip into the ignition that a car will immobilise but I don't fully believe that because I got just a normal key cut and tried it out (obviously didn't start the car) and the car didn't immobilise.

Stephen

I didn't think programming a key to work with your immobiliser was possible to DIY?

pclancy

Thought u needed the computer thing to plug into the ECU for some cars and for others (namely a VW caddy I had a few years back) it has to go to the dealer and their machine connects to some kind of vw database of codes etc?

Would be great though, I only have one fairly worn key for my primera and dont want to shell out €150 for a new one...

crosstownk

Tony Danza wrote:

I don't fully believe that because I got just a normal key cut and tried it out (obviously didn't start the car) and the car didn't immobilise.

The fact that the car didn't start means that it WAS immobilised!! This is how an immobiliser works - it doesn't read the correct code and blocks the control unit so the car will not start. Some models will fire up initially and then cut out - others don't fire up at all.

What you are planning may save a few € bt it has the potential to cause you many headaches and could well end up a waste of time and money. My advice is to just go to a dealer or car key specialist and get a spare key cut and coded.

It's highly unlikely that you will be able to code the key yourself without spending hundreds (if not thousands) of euros on the correct equipment.

Tony Danza

crosstownk wrote:

The fact that the car didn't start means that it WAS immobilised!! This is how an immobiliser works - it doesn't read the correct code and blocks the control unit so the car will not start. Some models will fire up initially and then cut out - others don't fire up at all.

What you are planning may save a few € bt it has the potential to cause you many headaches and could well end up a waste of time and money. My advice is to just go to a dealer or car key specialist and get a spare key cut and coded.

It's highly unlikely that you will be able to code the key yourself without spending hundreds (if not thousands) of euros on the correct equipment.

I meant didn't permanently immobilise the car.
Ok, so you've put me off the programming myself idea, but if I buy a key and a new blade, can a dealers program over whatever code is in the old key does anybody know?

crosstownk

Yep - a coded key can be overwritten.

A car will only be immobilised as long as an incorrectly coded key is in the ignition. Once you introduce a correct key the car will start.

KeRbDoG

Stephen wrote:

I didn't think programming a key to work with your immobiliser was possible to DIY?

It is atleast for 1997-2003 E39 BMWs

mondeoman

kerbdog wrote:

It is atleast for 1997-2003 E39 BMWs

& most Fords too,(once you already have 2 chipped keys that start the car);)
you can code a 3rd key

PADRAIC.M

what kind of car do you have I know the manual programming codes for most toyota,lexus,hyundai....

Tony Danza

PADRAIC.M wrote:

what kind of car do you have I know the manual programming codes for most toyota,lexus,hyundai....

It's a renault. I'm after buying a key and a blade on e-bay, was going to bring it into a dealers and ask them to program it for me.

Mr.Diagnostic

Chances are that they will only code a key that they supply. Worth a try though, you may be lucky.