Passat 3C Remote Key Fob Programming - Old Key

Hello, dear forum members .

I have been using your diagnostic set for almost a year; it is self-explanatory . However, I am now facing a problem that the manuals and Google cannot help me with .

So, about two weeks ago, I noticed that the remote locking function on my main key wasn't working anymore, probably due to a weak battery. So, I took it apart, removed the battery, and I've been using my second key for a while now.

Okay, so I bought a replacement battery, and now I can still start my car with the key fob, but I can't unlock or lock the doors. Everything works as usual with the second key fob.

Now I've read that you can only pair a key once, but that always referred to the WFS (presumably a specific system) and not the central locking system. I think that after two weeks without a battery, the key simply lost its coding for the central locking system.

Now the question is, how do I get this back into the key? So, only the ZV is missing, while the WFS seems to be present.

I would be very grateful for any help.

Greetings,
Ralf

OEM wrote:

So, I bought a replacement battery, and now I can still start my car with the key, but I can't open or close it. Everything works as usual with the second key.

Hi Ralf,

The WFS (Wireless File System) operates independently of the FFB (Footrest Footrest Box). The battery is only required for the remote control.

Therefore, the question is: Does the indicator light on the key illuminate when a button is pressed? It's possible that the "new" battery is simply dead or has the wrong polarity.

Greetings.
Guste.

Okay, I see . Yes, it looks great and the lights are working perfectly, but it's just not functioning.

Right off the bat: I will only be making assumptions in the following text, as I am also not familiar with the correct procedure.

Have you ever accessed the comfort control module using VCDS?
- What does the error memory indicate?
- Do the measurements perhaps provide any useful information?
- Have you looked at the adaptation channels? I would assume that VCDS offers corresponding assistance through the drop-down box of the channels. (e.g., key programming, etc.)

Perhaps someone with more knowledge will chime in.

Greetings.
Guste.

Hello Ralf,

I've experienced a similar problem before.

The car wouldn't open with my key anymore, but it could still be started.
Only with the key of my wife could the car still be opened using the keyless entry system.

The solution was that the FFB (presumably a device) somehow forgets the PIN code if you press it repeatedly without the car being within range.
The solution is in the Passat owner's manual, but I don't have it readily available right now.

In any case, the cover plate on the emergency lock on the door handle must be removed, and then the emergency key must be inserted into the lock.
Then, press the "Open" button on the FFB (Front Fascia Board), and when the car opens, it must be started using the key that didn't work previously.
Of course, this will only work if the LED on the front control panel is lit, meaning the battery is fully charged.

Perhaps this will help you.

Best regards, Mario.