Cruise control not working (1Z)

Hello,
I installed a single DIN radio in my VW T3. Now I'm stuck with the cruise control issue.
The engine is a 1Z from a Golf 3 manufactured in 1994.
All the necessary sensors are installed (speed, brake, clutch).
I suspect that the problem lies with the engine control unit itself (part number 028 906 021 C).
I've also already scanned it, and it doesn't produce any error messages. In block 6, it shows the brake and clutch, but not the status of the cruise control lever. This led me to suspect that the switch (which I bought new from VW) was defective. So, I tested the switch with a multimeter, but it seems to be working correctly. Then, I tried bypassing the switch by connecting it directly, but still, I didn't get any signal in the control unit.
The cables are connected to the correct pins (white cable from the switch to terminal 15, blue cable from the switch to control unit pin 34, red cable from the switch to control unit pin 35).
The black cable runs from the switch to control unit pin 66 and also has continuity.
It really seems like the problem must be with the control unit now, doesn't it? What do you think?
Greetings.
Tobi.

I assume that the GRA is successfully enabled in the STG.

What does the last field in block 006 say?

Does the letter "G" appear on the initial login screen when you access MSTG?
In the field "Component": http://www.ross-tech.com/vag-com/images/small-opencontroller.png

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

Yes, it's enabled; for me, the value is 0 (a value of 255 or 225 would indicate that it's disabled).

Hello T3Tobi.

255 indicates that the GRA (presumably a system or service) is blocked.


Best regards,

Thank you, I will find out more information elsewhere.
As I already mentioned, the value is showing as zero for me!

Thank you, I will find out more information elsewhere...
As I already wrote, for me, it shows as 0!!!!!!!!!!!!!!!!!!!!!!

Why inform otherwise? Do you not like the (correct) answer ?

You know, I was hoping to get a potentially useful answer from the "experts" here. I've already mentioned that it's set to zero and activated on my end, so do we really need to repeat that?

Hey Tobi,

Why do you immediately get so "defensive" when someone corrects your misunderstanding or points out that your "255 or 225" answer is incorrect? Especially since you didn't really explain what you meant by the answer "225 or 255."

It's incredibly difficult to provide remote diagnostics during a renovation project, especially when there are so many potential mistakes that can be made.

We do this for free and in our spare time, so we're giving it to you as a gift.

I (personally) believe a slightly more friendly and defensive tone would be appropriate in this case.

Greetings.
Martin.

Is there still any useful information available from a user?
It's incredibly frustrating when you carefully explain something, and people repeatedly claim to be reading something different.
It's not meant to be malicious...

It sounds like the common connection (terminal 15, as you mentioned) to the switch isn't working correctly. Have you tried connecting terminal 15 directly to the input pins of the TCU and checked? It could be a loose connection or high resistance somewhere.

I find it hard to believe that the STG was fired in such a way as to cause this type of failure.

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."