Replace engine control unit (ECU) for VW Passat B7, 2014, 1.4 TSI, 118kW

Hello, I'm new to this forum and have a question regarding replacing the engine control unit (ECU) on a Passat.
It's a 2014 Volkswagen Passat B7 with a 1.4 TSI engine, 118 kW. Mileage: 86,600 km.
Before I just start, I'd like to be a little informed about exactly how I need to proceed.
I am, of course, using the official and latest version of VCDS.
I have already made a copy of the control unit coding using VCDS, but without entering the access authorization (login code). I'm not sure if that's sufficient, though. (By the way, where can one find the login code?)
Furthermore, I have a question about how the immobilizer system works. How can I program it into the "new engine control unit" so that it allows the engine to start? Do I have to go to a VW authorized service center?

Reason for changing the control unit:
Error: Misfire detected in cylinder 2.
"Vehicle jerks under load." The error occurs SPORADICALLY. Several checks have already been performed, and various parts have already been replaced (spark plugs, ignition coils, fuel injectors, wiring harness).
The car was at a VW authorized service center, and they charged the customer 3000 Swiss Francs for diagnostic work.
Replacing fuel injectors, replacing ignition coils, replacing spark plugs, checking compression pressure, checking valve timing, checking cables, etc. Unfortunately, the error is still there.
Now the car is in my workshop, and I need to find the problem quickly and efficiently . I have already performed all the mechanical checks, and the known TSI problems don't seem to apply in this case.
Since the spark plug wires, spark plugs, ignition coils, and fuel injectors are already new, I'm ruling them out as the cause. (Just to be sure, I swapped the spark plugs and ignition coils again, but the problem doesn't move to a different cylinder.)

What's likely left is a faulty engine control unit, camshaft bearing, valve spring, etc.
Since checking the camshaft or valves is a very complex process, and the error only occurs randomly and sporadically, and the measured compression pressure is the same for all cylinders and within the tolerance range.
I believe it's more likely to be an electrical/electronic problem, specifically related to the control unit.

I look forward to your answers .

Sincerely,

Ueli Schelbert.
www.kultkarren.ch

Hello Ueli,

A vehicle scan also includes the coding information for the installed control units; please save this information.

The adjustment values cannot be recognized during the automatic scan, but this should not be necessary in your case.
Please check which adjustments are possible in your engine control unit (ECU) and what parameters they affect.

Quote:

Furthermore, I have a question about how the immobilizer system works. How can I program it into the "new engine control unit" so that it allows the engine to start? Do I have to go to a VW authorized service center?

With an "unchanged" engine control unit (ECU), the immobilizer needs to be adapted to the vehicle, which unfortunately can only be done at an authorized dealer in your case.
Depending on the type of control unit you use as a replacement (e.g., a used part that has been modified), it might be possible to use one with the immobilizer disabled.
The question is whether it's a good idea, considering your car isn't that old yet.

Quote:

Error: Misfire detected in cylinder 2. "Vehicle jerks under load" error occurs

SPORADICALLY.
Is the compression okay, and are the valves sealing properly and not broken?
Please check the long-term adaptation values for the lambda control system to determine if it is possible to exclude the fuel injection system as the cause of the problem.
Okay, I'm ready. Please provide the German text you want me to translate.

Best regards, Rainer.

Control units can also be repaired. Especially with minor issues like a faulty power stage, it's a relatively simple task. I would definitely try that. There are specialized companies that offer these services.

When troubleshooting, it might be helpful to consult the wiring diagram to ensure that a single pin in a multi-socket connector isn't the source of the problem.

The immobilizer only establishes the online connection for a VAG garage.

First, please perform a full system scan. We are particularly interested in the error code.
And now, your observations: when do these misfires occur (engine temperature, partial or full load, RPM range, outside temperature, etc.)?
hg
Herbert.

Hello everyone.
First of all, thank you very much for the already very helpful answers you have provided.
I wanted to copy a diagnostic report today and post it online for you.
I drove around for 2 hours, going uphill and downhill, sometimes pushing the car hard and sometimes driving gently... but to my absolute astonishment, the problem didn't occur again.
I'm not sure if this could be related to the outside temperature, because today it was -0.5°C here, but on Saturday when I received the car, the error appeared immediately after a short test drive (outside temperature of approximately 2.5°C).
I have to admit that on Sunday, I moved and tested every inch of the cable harness from the engine control unit to the ignition coils in every conceivable way. I even removed the engine control unit and visually inspected the pins... but I couldn't find any results. Everything looked perfect, and the cables, as far as I can tell, don't have any breaks. The only thing that looks a bit worse is the housing of the control unit... (it's oxidized).
Okay, I'm not really sure what to make of all of this. I'll drive to work tomorrow, which is about 100 kilometers round trip, including highway driving. Let's see what happens.

Best regards,

Hello! Did the error occur again?

If you want, I could clone the STG for you.

Greetings.