MKB BKD: Engine Control Unit Tuning/Remapping

Hi everyone,

My brother's Touran (103 kW, without DPF, BKD engine) averages 10 liters of diesel per 100 kilometers.
Now I'm trying to find the problem, and the workshop has already replaced quite a few things under warranty.
Engine, turbocharger, mass airflow sensor, transmission, etc.
Almost everything has been replaced - the fuel consumption has been an issue since the car was new, and it should have been resolved by now, considering it has 190,000 km .

Now, I've noticed something that seems inconsistent.
The channels are not displayed when adapting the engine control unit (03G 906 021 KF).
First, like with all other users, it requests access permission. After entering the login credentials, it successfully acknowledges them.
If you now want to access the previously blocked channels (e.g., 1, 2, 3, 4, 5, etc.), you will see...
"Channel number not available."

A few months prior, I had a rental car. It was the same Touran model, with the same engine code and the same control unit (03G 906 021 KF).
At that time, out of curiosity, I connected to the diagnostic system, and strangely enough, I was able to access the internal channels.
Same control unit, same software version.
Now I'm assuming that the MSG has a way to fix the issue, and I went with the customer to the workshop on inspection day to show the mechanic what was happening.
The fact that he had almost no idea about it is bad enough, but let's put that aside for now.
Now, the workshop claims that even with this login, you don't necessarily have to access the system, and that VW has had certain software versions blocked from accessing those channels.
You can only access it if VW enables the adjustment through a TELEDIALOG (whatever that may be ).
I tried to explain to the technician that I had been able to connect with the exact same vehicle before, and without receiving any error messages. However, he started stammering, mumbled something incoherent, and tried to dismiss me by saying, "The connection seems to be bad... I can't understand it."

What do you think about this? Am I right in assuming that VW might be blocking access to certain control units? Or is it possible that they are doing so?
"Why does it first show 'Access permission required', then successfully accept the code 12233, and then later display 'Channel number not found' where values should be displayed?"

Best regards,
Serdar.

Does anyone have any ideas?

Hi,

The only possibility that seems likely, especially if you're not the original owner of the car, is that there's a "genuine" data state in the control unit, even though it might not be entirely original.

If you can rule that out, then troubleshooting the engine is the next step. First, check the coolant/diesel temperature sensors.

Best regards, Rainer.

Hi Rainer,

The car is in its original condition, having been purchased new and used as a taxi in Wolfsburg. Any chip tuning or other modifications can be ruled out.
How to check the coolant/diesel temperature? Are you referring to the comparison when the engine is cold, where both temperatures must match the ambient temperature within +/- 3 degrees?

Best regards,

Yes, for example, they should also provide meaningful values when the system is running at its normal operating temperature.

Best regards, Rainer.