MK4 key fob programing question

[BlowMyTurbo]

hey everyone, so little background i did a all swap on a mk1 TT and after doing so i wanted to get my vw key working to unlock and lock the car. the ECU, Instrument cluster, and RFID are all out of the Mk4 Jetta so they should work just fine as if the it was still in the jetta, but for some reason i can't seem to get it to work using VCDS as i only have one cut key. anyone have any ideas here? i know its kind of a weird situation but thought id pick some of balls brains.

 

[hughesjasonk]

Need a vago-tacho to get you sik code to program more keys

 

[BlowMyTurbo]

Need a vago-tacho to get you sik code to program more keys

I was wondering if that was going to be the issue, so I still need the pin code to do so cool I will give it a try.

 

[Nuje]

When you say "lock, unlock the car", you mean just using the key fob for the doors, right?

In which case, no - you don't need the PIN...the PIN is only necessary to program the key's RFID to communicate with the ECU/cluster for the purpose of starting the car.

VCDS is all you need. Read and follow carefully the instructions on Ross-Tech's website.
You might need to "erase" all previous remotes, and then add in your new remote. But then sometimes, for whatever reason, a key's electronics won't get matched.

I just programmed a fob to a parts car - it doesn't even have the key-blade portion attached...and I was able to program that remote using only the valet key in the ignition, along with VCDS.

 

[Vince Waldon]

Yup, let's save some time and confusion and be clear. There are two parts to the key:

1) the passive RFID chip embedded in the key body that communicates with the cluster, which then tells the ECU if the key is valid. The clusters's Secret Key Code (SKC) is required if teaching the cluster about a new RFID chip, and VCDS by design cannot retrieve SKCs.

2) the battery-powered radio transmitter in the fob that communicates with the Comfort Module, activating door locks etc. VCDS can pair a new fob with the Comfort Module, and there's also a manual method of training the Comfort Module about a new fob if you already have a working fob.

 

[BlowMyTurbo]

Yup, let's save some time and confusion and be clear. There are two parts to the key:
1) the passive RFID chip embedded in the key body that communicates with the cluster, which then tells the ECU if the key is valid. The clusters's Secret Key Code (SKC) is required if teaching the cluster about a new RFID chip, and VCDS by design cannot retrieve SKCs.
2) the battery-powered radio transmitter in the fob that communicates with the Comfort Module, activating door locks etc. VCDS can pair a new fob with the Comfort Module, and there's also a manual method of training the Comfort Module about a new fob if you already have a working fob.

so i have one working key that is not a fob, its just a standard key with the rfid, and then i have a fob I'm trying to connect to the car. I've tried multiple times to program it using the VCDS tutorial but when it says the press the unlock button to connect it does nothing, I'm sure the key is powered as well.

 

[Vince Waldon]

One thing to try (if you've not tried already) is to set the number of fobs to "0" and save. You then set the number of fobs to "2" and retrain the car to both fobs back to back.

Sometimes I've found the car won't be retrained until it's set to 0, and sometimes doing them in from scratch helps me localize the issue to the car or a specific fob. There are lots of sketchy fobs out there, unfortunately.

There are also two different versions of the fob, although if I understand you correctly you're just trying to get both fobs that used to work on the original Jetta now working on your swapped car?

 

[BlowMyTurbo]

they only key have working on the car is a standard key with my RFID from the swap and i have to unlock with the door locks, i have my old wireless fob that I'm trying to connect to the car, it has no RFID but works as i press the buttons and the light flashes, when i go into VCDS and do the process and change the value in "21" from "0" to "1" and i press the button and save nothing happens. i click read again and it says 0 again.

 

[Nuje]

Yeah - like I mentioned above, some fobs just won't re-program, for whatever reason.

I had a guy here sounds similar to you: One working key, one fob from old car (we were just trying to get the electronics to lock/unlock doors), and one brand new (not yet cut).

Tried at least six different times to reprogram all keys, but that one from the old car just never "beeped" to acknowledge pairing. The old one would, the brand new one would, but that one from the old car....nothing. And i've reprogrammed fobs from different cars many times, so i know it's possible.

As Vince Waldon mentions, even though some keys have the same look/shape, the radio frequencies they work on are different. So that could be the issue. Or for whatever reason, it's "locked" (no pun intended).

 

[benmarks]

I am unclear from the earlier posts, do you have the SKC?

 

[BlowMyTurbo]

so would my best bet be to buy a new board for the key?

 

[BlowMyTurbo]

I am unclear from the earlier posts, do you have the SKC?

no i do not

 

[benmarks]

So, the VCDS steps won't work without it, right? That may be why it's not working for you. Or, am I missing something.

 

[BlowMyTurbo]

So, the VCDS steps won't work without it, right? That may be why it's not working for you. Or, am I missing something.

i believe you do not need the pin code unless you are trying to program the actual RFID chip in the key. not just the lock/unlock as i am.

 

[benmarks]

Which one of these are you using?

https://www.ross-tech.com/vag-com/cars/vw-remote-matching.html
https://www.ross-tech.com/vag-com/cars/key-matching-4digit.html

I am pretty sure the 2nd one requires the SKC.

There is also this process, but I am not 100% sure it works with just the valet key. I think it does:

1) Unlock the door to your car using the key blade
2) Insert your old key blade into the ignition and turn it to the "on" position, but do not start the car.
3) Roll down your driver's side window
4) Step out of the car and insert your new key into the driver's door lock, now turn the key to the left and hold it in that position for 10 seconds.
5) Now press the lock button on the FOB
6) Now press the unlock button on the FOB

 

[Nuje]

Even if he had the 4-digit PIN / SKC, it wouldn't help him with remote-matching.

I'd say to go with new key electronics.

 

[BlowMyTurbo]

so update:

I ordered new key internals, so just the actual board itself. put it in the old housing and same issue, the key will not program. Is my issue that I need more than one key and do the 2 key method instead of trying to use VCDS?

 

[BobnOH]

Well there is a setting for number of keys. It sounds like the car still does not recognize that remote. Needs programmed.
This might help

 

[Nuje]

I just programmed a new key - got it cut first, paired to cluster/ECU with VCDS, and then went to do the remote matching. Didn't work. Tried at least four different times, swapped which key was in the ignition....no dice.

Remembered that I'd dissected an old key way back, dug out those electronics and swapped them in...tried the remote matching again - SUCCESS!

I have three new fobs now, with internals that I can't get to pair with any Mk4 cars. They must be using a different RF signal or something. This would be borne out by the fact that the actual circuit board, while the same basic shape to fit the plastic fob housing, is laid out a little differently - microchip is a different size and placed slightly differently.

Edit: Here's the issue. The key I bought was part number 1J0 959 753 AH; the key I have (that works) is 1J0 959 753 DC.
Photo below contains what's on my key fob that I've had no problem pairing to at least four different cars. Note the vertical writing that indicates 315MHz, and the associated Hella part number as well.

 

[benmarks]

I still think it might be worth trying the other process if the SKC can be attained.

 

[Vince Waldon]

That procedure is for teaching the car about the passive RFID part of the key, so the car will start..and does require the SKC.

As I understand it the OP is trying to match the fob (lock/unlock doors) active part of the key...not SKC related.

 

[Nuje]

SKC has nothing to do with the remote's functionality.
(Edit: Vince Waldon beat me to it, but yeah...what he said.)

 

[benmarks]

Doesn't it do both? If you get a new key fob, you don't have to do both procedures, right?

 

[Vince Waldon]

Two separate components in the key, talking to two different receivers in the car, controlling two separate subsystems within the car: two separate procedures.