A6 2.5 TDI ECU Replacement (AEL)

Hello hobbyists and professionals,
My engine control unit seems to have failed. The preheating light is no longer turning off, and while the engine is still running, it's not drivable anymore (it's sputtering and has no power). It's also no longer responding to diagnostic attempts.
Now, my questions: Can I simply exchange this for another used one?
If so, is there anything that needs to be adjusted, such as pairing the keys (WFS)? Could it be that the device is simply digitally locked up and can be revived with a reset?
I'm hoping I won't need a new one.

Regards,
Kai.

Hello Kai,
If your starter motor is actually defective, you can replace it with a new one. However, you will then need to adapt the immobilizer to the new starter motor.
You won't need to reprogram the keys after that.

Hello,

I'm just wondering why it even starts and responds to the throttle. The power output is probably less than 10 horsepower.
I guess I'll have to get a new one. If I find the right setting, I need to enter a '0' into 'Device 25 Adaptation (10)' in channel 00, and then the thing should start working again.

Regards,
Kai.

Yes, that's exactly how you do it; that's how you delete the learning values.
Can you establish a connection to the immobilizer (25)?
Is the cable to the MSG (whether it's the K or L line, I don't know for your specific car) in good condition?
I would check that before making the exchange.

Hello,
I can access all the other components, but not the engine control unit (01). That's why I suspect it's faulty. Just a week ago, it was working fine, but now the glow plug light is constantly on, the engine has zero power, and it sounds awful.
Now that these control units are difficult to obtain at a reasonable price, I have a few questions.
Does anyone happen to have one of these lying around in their basement (part number 4A0 907 401 P - AEL-6-speed)?
Can you also use a part from an AAT (4A0 907 401 E) or an automatic transmission, and just swap the chips? (This question has been asked before, but unfortunately, it hasn't been answered).

Regards,
Mathias.

Hello,


I've read a lot online about immobilizer issues, and now I'm a bit confused. I have a problem: I've installed a second engine control unit (ECU) with chips for my 1998 Ibiza 6K AFN. When replacing the ECU, I now need to recode the immobilizer, and I thought I always needed the 7-digit PIN for that. However, I've read here that I only need to enter '0' in channel 00 during the adaptation process, and then it should work again. Is that correct, or have I misunderstood something? I've already requested the PIN, but unfortunately, my SEAT dealer isn't very cooperative or fast, and I've been waiting for it for 2 days (they're acting difficult because I want to do the adaptation myself at home).


Thank you for your tips!



Sure, here is the translation of the text from German to English:

'MFG Dr.B' translates to 'Best regards, Dr.B' or 'Sincerely, Dr.B'.

Don't be confused! It's not stated anywhere that an A6/96 is the same as an Ibiza/98.
Otherwise, just try it out. Just remember the number that was there before, but I don't think it will work.

Regards,
Mathias.

If you want to replace the engine control unit (ECU), you only need a PIN if the car has an Immo-3 system. With Immo-1 and Immo-2 systems, you can simply save the value '0' to channel 00 and that's it.

Immo-3 can be identified by the fact that the immobilizer displays the vehicle identification number (VIN), and the engine control unit (ECU) also shows immobilizer data. In Immo 1 and 2, the immobilizer only displayed an immobilizer ID, and the engine control unit did not show any immobilizer data.

I believe the first Immo-3 systems were introduced in the model year 2000 with the A8. In other VAG models, Immo-3 was introduced in the model years 2001-2002.

Whether it's an A6/96 or an Ibiza/98, no PIN is required to replace the engine control unit.

-Uwe-

I bought your exact control unit used for 200 euros, but it wasn't actually needed because there was no defect in the control unit in my Audi from 1995; the AGR (Exhaust Gas Recirculation) system was faulty. I had already experienced excessive exhaust emissions and assumed it was the control unit. After joining the forum, I deactivated the AGR system, and since then I haven't had any problems. I would like to sell the control unit for 150 euros.
Best regards, Achim.

@Achim: Too bad, the offer came too late, I already have one. However, if it includes chips, I would take it.
@everyone: The WFS (likely a vehicle control system) has almost driven me to despair. Simply entering 'STG 25 Adaption 10 Channel 00' and changing a '0' doesn't work! After turning the ignition off and on, it just doesn't work. It only worked when I disconnected the battery immediately after the adaptation and then reconnected it.

Regards,
Mathias.

Can you please describe the process in detail for the Ibiza model? I'm experiencing the exact same problem.
"I can access the WFS, but as soon as I click on 'settings', 'login', or something similar, nothing happens. There are no error messages, but also no other reaction."

With which device (which version) are you trying this? What is the procedure?

Sequence of events:

25 Workflows.
10 adaptations.
Channel 00, that's it, nothing more happens from here.
Interface, version 303.

Procedure:

25 Workflows.
10 adaptations.
Channel 00, that's it, nothing more happens from here.
Interface of 4 letters, version 303


That is your problem.

It seems so. I haven't had any problems with it before, but I was just at a friend's place who has a KTS, and it worked perfectly on the first try.