Golf 4 Dashboard Burned - Instrument Cluster

Hello,
My son's Volkswagen Golf 4 Variant TDI, first registered in 2000 and with 270,000 km on the odometer, broke down.
While driving, smoke started rising around the instrument cluster.
After stopping and turning off the ignition, the smoke stopped.
"However, the pointers were in random positions, and some of the indicator lights were on."
Turning the ignition on and off did not resolve the issue.
The engine still starts, but immediately shuts off again, so the immobilizer is not disengaged.
Disconnecting and reconnecting the battery shows no effect.
Reading the data with an OBD tester that has always worked on this vehicle is not possible.
He's unable to connect.
I have removed all the trim panels from the driver's footwell and inspected all the cables for damage; everything looks normal. No fuses are blown.
A combination instrument with the same part number was obtained and connected, the ignition was turned on, and it displayed the same symptoms: random needle fluctuations and various lights being illuminated.
"Still no connection with the OBD tester."
I opened the "smoked" AI (Motometer), and there are significant burn marks (photos).
I also opened the replacement device (VDO), and there were no signs of burning, but it was only connected for 10 minutes.
It seems there is also an error outside of the AI system.
How should I proceed?
I would be very grateful for any help you can provide.

Best regards,
Marcus.

Hello,

I would check all cable connections leading to the AI for any signs of wear or damage.
When working on your car, the immobilizer is located in the instrument cluster and communicates with the engine control unit (ECU). Therefore, don't forget to also check the wiring harness leading to the ECU.

Best regards, Rainer.

In order for the bare copper on the circuit board to become visible, a few amperes must have flowed through it. Therefore, it is quite possible that a power line was also overloaded.

You mentioned you checked the cables in the footwell. How does it look directly around the connector area behind the instrument cluster? You should have good access there and be able to easily check things. You can also easily disconnect individual pins from that connector, allowing you to test whether the instrument cluster shows these errors with just + and - power (probably not), or which additional cable causes the error to appear.

I would download the wiring diagrams from Volkswagen's Erwin (siehe Fehlerdatenbank) system and use them to continue my search. Unfortunately, it might be quite time-consuming.

Regards,
Sure.

Here is the translation of the text from German to English:

"Guste" means "gust" in English. It can also be used as a verb, meaning "to gust."

I have downloaded the circuit diagrams.
I have exposed the wiring harness for the blue and green connectors.
I will now bring in all the suspects one by one.
I am reporting...

I monitored the 2x +12V power lines in the blue connector with an ammeter, and I also plugged in my spare control unit again.

Only 300mA of current was drawn initially, but after about 30 seconds, the current increased. I stopped the process when it reached 4A.

I have the circuit diagram and I've studied it thoroughly.

Then I removed the wires from the blue AI connector and plugged them back in one by one.

All connections are in place, but there is no increased current flow, only 330mA.

The error seems to be gone!

"No damage detected in the replacement AI; all indicators are behaving normally; the engine is only running briefly because it's not needed."
WFS adaptation.

How do I train the AI?
Burnt-out AI: Motometer 1 J0920 805E.
I have a VDO 1J0920 805E that may have been damaged during testing.
I still have a Motometer with the part number 1 J0920 805E.
I would like to learn that.
What hardware/software do I need?
The AI should be called "Immo2".

Thank you.

Hi.

http://wiki.ross-tech.com/wiki/index.php/Immobilizer_II_ECU_Swapping

Possibly only available at the .

AI encoding: See the old vehicle scan data.

Best regards, Rainer.