Buying a new key for your Golf or Bora

[old_n07]

 

Getting spare keys working on the MK4 platform can be a bit of a nightmare at first glance so here are a few pointers:

Key overview:

There are four types of key on the MK4 platform all have an immobiliser transponder fitted to facilitate starting the vehicle.

1. Standard non-remote key



2. Emergency key (plastic):



3. Two button remote early type:



4. Two button remote late type:



 

The two button types can be seperated in two by grasping the key firmly in both hands and pulling the two halves appart, the top half with the buttons contains the remote control for locking and unlocking the car and the bottom half has the key blade and immobiliser chip inside.

Top







Bottom





The immobiliser chip is highlighted in red in the last picture, these are made of glass and are very fragile - they are glued into the original VW keys and are next to impossible to remove without breaking and once cracked they don't work.

 

Spare Keys \ Remotes
1. Remotes (top half of key)

If you want a new \ replacement remote fob then you need to make sure that the part number and frequency of the remote matches your current key fob. The replacement key fob can be a used item.

To check your current key frequency you need to seperate the key in half then turn the top half over, on the back is the part number and frequency info





There are two frequencies make sure you get the correct one!

 

2. Keys (bottom half of remote key or standard non-remote type key)

As the key bottom half contains the immobiliser chip there are a few things to look out for when buying a new \ replacement key, as keys that have been coded to an immobiliser 3 vehicle can't be recoded to a new vehicle as the chip is write once.

Ideally buy a completely new key that has not been coded to another car before.

If your car is immo2 based:

You can buy a second hand key but you will need a new key blade to be cut, however the key can't have come from an immo3 vehicle as it can't be recoded

If you car is immo3 based:

The key can't be second hand (used), you will need a key bottom with a virgin transponder fitted to enable it to be coded to your car.

Beware on eBay when looking at keys, the add may say new key blade fitted, this however does not mean that the transponder chip is new and uncoded so you might end up with a key that unlocks the car but can't be coded to start it afterwards - If in doubt explicitly ask the seller if the key has been coded to a vehicle or not and does it contain a virgin transponder.



Once you have your new key it will need coding to your car, you will need the SKC (secret key code) to match the immobiliser chip to the car but you don't need the SKC to match the remote part for locking and unlocking the vehicle, some older cars had the SKC provided on the key tags that came with a new car. If yours didn't then it can be retrieved with some third party tools such as Vagtacho.

VCDS (VagCom) can't retrieve the SKC code

Hope that helps

Neil

UPDATE:

Here are a couple of links to how to's on coding in new keys

The key in the door method for matching the immobiliser: http://uk-mkivs.net/forums/t/17868.aspx

Using VCDS (Vagcom) you will need the SKC code to do the immobiliser matching though: http://uk-mkivs.net/forums/t/257087.aspx

[Rhyso]

Top guide Neil

[richw911]

Top guide Neil

Indeed awesome 

[Car nut]

Top guide Neil

+1 

[Mr_Orange]

Good job!  Just what the Dr ordered!

I only got the one key (late 2 button type).

[Wurzel]

My key remote seems impossible to open, like it's welded itself shut. I've tried sticking a screwdriver in the slot when the key is out but it's just chewing up the rubber/plastic. Any tips?

Also where can you get the keys cut? Just a normal key cutting store?

[Mr_Orange]

My key remote seems impossible to open, like it's welded itself shut. I've tried sticking a screwdriver in the slot when the key is out but it's just chewing up the rubber/plastic. Any tips?

Also where can you get the keys cut? Just a normal key cutting store?

Get a nice French polish nail job and try again?

You can only get these cut as specialist key cutting stores like Timpson or at a VW dealership

[Wurzel]

I honestly think the previous owner must have glued the two halves together! There seems to be glue residue at certain points.

How much does the cutting cost?

[Mr_Orange]

 :embarassed:

I've just been bitten by a part number issue:

I've got a "753N" remote operating at 434Mhz

Seems there is also a "753N" operates at 433MHz 

Make sure when you are buying that you double check the part number and match the frequencies!!

[mar_k]

not sure if ive read this wrong, but can a used mk4 golf key which was registered in 2000 be recoded to a different car or do you need a virgin chip?