Engine control unit locked, Golf 2 TDI AFN

Hello diesel mechanics.

I had my Golf 2 with a 1.9 liter TDI AFN engine running, and it always started immediately. I then measured the large round connector with a voltmeter to determine which wire was for the parking light. Now, the vehicle won't start. I read the error codes with VCDS 908, and the error log shows "Engine control unit locked." Can you help me? I'm stuck.
Best regards.
Olli.

Hi,

Your connection to the immobilizer is not working, or the immobilizer may not be cooperating (combination addresses 17 or 25 for separate systems). Read out the control unit.

Best regards, Rainer.

Hello.

Thank you for the quick response. Do I need to enter the number 17 where the address is supposed to be entered, and does "Start bei vcds" indicate a starting point?
Best regards.
Olli.

ollli wrote:

Thank you for the quick response. Do I need to enter the number 17 where the address is supposed to be entered, and does "Start" refer to vcds?

Either do it like this, or you'll have to use a different dashboard. But it probably won't work because the engine/control unit is likely from a Golf III or Passat 35i. For these vehicles, you need to bypass the immobilizer (address 25) because the speedometer on these vehicles is not accessible via OBD.

Combination instrument = Control panel module = Control unit address 17. The term "circuit breaker module" is not very well known, however.

Rainer K. wrote:

The term 'distribution board insert' is not very well known...

In VCDS, however, it is called that.

No, that's not what it means. With which you simultaneously position yourself as a competitor.

I specifically replaced the term "Schalttafeleinsatz" with "Kombiinstrument" because no one actually calls that part by that name in practice. These are just those small but significant differences where, for the user, either questions arise or everything is clear.

Google says:
6,470 for switchboard installation.
143,000 for combination instrument.

The same part is therefore known under the name "Kombiinstrument" 22.3 times.

Hello.

I entered the number 25 under "Selection" and then pressed "Start." The error message "No response from the control unit" appears.
Do you know how I should proceed from here?
I also clicked directly on the "Immobilizer" button, and I get the same error message.
Best regards.
Olli.

Well, now you know why the engine control unit doesn't like it.

So, it's either a faulty immobilizer control unit or the wiring. I'm leaning more towards wiring.
[Edit: Please also try address 17, I'm not sure how you converted the AFN to a G2. In principle, both are possible, either a different combination instrument or a separate immobilizer control unit.] In any case, the wiring is homemade and therefore needs to be checked.

Best regards, Rainer.

Rainer K. wrote:

Which simultaneously positions you as a competitor.

You're right, point to you. I didn't know it's called something different where you are.

Hello.

Thank you for your replies. I will check the wiring tomorrow. How can I tell if the immobilizer control unit is defective? Are there any identical replacement control units available for these models?
The control unit comes from a Golf 3 TDI.
Best regards.
Olli.

Hello.
Is the LED on my interface constantly green, even when reading data? Is that okay?
Best regards.
Olli.

Hello.

I was able to fix the problem. I connected a wire from the immobilizer to terminal 15 (positive), and it started working. The engine control unit is no longer locked.
Thank you all!
Best regards.
Olli.