T4 Engine Conversion: AFN to AQN - WFS Issue & Update

As the title suggests, I installed an AFN engine in my T4 van. I used a complete donor vehicle for this, which was also in working order because I had driven it for a few days beforehand.

Okay, so my problem is with the immobilizer. The car starts briefly and then immediately shuts off, and there are the following two error messages:

"Key signal too small and key not authorized, but it doesn't matter which of the two keys I try."

"But I took everything from the donor vehicle."
Could the key have been lost?
or maybe the antenna is broken!? Which would be quite a coincidence, considering it was working just two months ago.

I've already tried searching here, but unfortunately, I haven't found anything relevant.

Can anyone help me here?
Thank you.
Hi Chris,

The T4 bus has an external WFS box. Normally, Did you take it from the donor vehicle, or did the donor vehicle perhaps have the WFS directly integrated into the engine control unit? Is the reading coil connected and working? A signal that is too small usually indicates that it is not being recognized.

@Mulle:
Do you know of any AFN (or its corresponding STG) that includes the WFS?
There was a version of the system that used a WFS as a standalone component; there was also a version that integrated the WFS into the speedometer.
possibly also, but directly?

Best regards,
Rudi

Passat, Golf (4) AFN, manufactured in 1997 or 1998, has it in the MSG. However, since we don't know which specific engine we're talking about, this is pure speculation.

the variant with WFS in the speedometer

The WFS data (key data) is in the speedometer. The WFS itself is in the MSG. If it's deactivated, you can plug in any speedometer. Rudi, you know that, don't you? Are you just trying to annoy me?

I didn't want to upset you *smiley with halo* ...
It was more of a misunderstanding.
The WFS functionality has been included in the TDI models since the MSA12 series (e.g., 021) and is now part of the MSTG.
I understood your statement to mean that there are vehicles with WFS but without any additional features.
Control unit (neither the box at address 25, nor the instrument cluster) for handling.
the key provides.

Best regards,
Rudi

hello you two
Okay, so "Spender" is a Seat Ibiza, manufactured in 1998, as far as I understand. It has a separate WFS control unit and everything is completely connected, including the antenna and the box.
It was a 6-pin connector.

and of course, it's also connected to the diagnostic system.

My bus didn't have any of those features, so it had no engine control unit (ECU) and no immobilizer. It was a very basic 1.9-liter naturally aspirated diesel engine, using the simplest but functional technology.

and now... with the new engine, he doesn't want to

Okay, so I tested a different/new reading head today, just to see... and it's still the same problem... it turns on briefly, and then immediately turns off again.

and still the same two errors.

Can someone tell me what I need to pair the key fob, or how it works?
I have the small tester available, the 1552.

And no, I don't have a PIN/code for the keys.

freez wrote:

hello you two It was a 1.9-liter naturally aspirated diesel engine, a simple but functional piece of technology.

Hi,
For the sake of completeness...
Your old engine has the model code 1X, not 1Z.

So, you've taken the engine control unit AND the immobilizer control unit AND the transponder coil AND the key from the donor vehicle, right?
Or is it pieced together from various sources?

How did you attach the reading coil to the ignition switch? Does it simply fit on a T4 with a 1X engine?

Regards,
Jens.

Okay, sorry, just once, of course...

Yes, everything fit together perfectly from a mechanical standpoint.
and I took everything from a single donor vehicle... including the engine control unit.
immobilizer control unit, key reader coil, etc.
Currently, I have the coil lying loose until it works, and the key(s) are still in the lock that's attached to or around the coil.

Okay, so I also removed the donor car's ignition switch, but I haven't connected the ignition coil yet. That shouldn't have any effect, though.

just to make sure the key is properly seated and the spool.

freez wrote:

yes, sorry, just once, of course... Currently, I have the coil lying loose until it works, and the key(s) are still in the lock that's attached to or around the coil. Okay, so I also removed the donor car's ignition switch, but I haven't connected the ignition coil yet. That shouldn't have any effect, though. just so that the key

fits properly and the spool }.

Are you sure everything is wired correctly?
In TDI conversions, wiring errors are among the most common pitfalls.

Regards,
Jens.

I'm confident about the wiring because the fuse box was/is identical, and the plugs only fit in one position.
And believe me, I've already tried quite a few things and taken measurements, or rather, my electrician has.

They've already been going back and forth on this, etc.

Okay, I've heard several opinions now. One person says that because the battery was disconnected for so long, it's possible that the keys have "forgotten" their programming.
The other person, on the other hand, says that's not possible, that you can't lose the ability to use keys.

My problem is that I no longer have the four-digit PIN/code, and I can't reach the previous owner.

and they say that you can only apply for the key online now?
That means going to the Seat dealer of my nightmares!

Is there another possibility?

Okay, I've read out both control units.

The following numbers are registered: 028906021EK and wfs 6H0953257A.

I also tried to remarry the two modules by deleting the learned values and adjusting the WFS control unit, but my tester says that "this function is currently not possible."

'function is currently not possible' is what my tester wrote to me!
Certain functions are not compatible with all 1551/1552 models. If you're unlucky, the feature on your...
This function is currently disabled.

Best regards,
Rudi

@rudi... uh, that would be quite something.
Damn... what other options would I have then?!