Troubleshooting after error reading

After I had problems with my Polo (9N 1.9l, 2004), specifically with the orange warning light (the same one that appears when ESP is off),
I performed a diagnostic scan on a friend's car.
However, since it cannot perform a faulty diagnosis, we still cannot proceed.

It concerns the following errors or error codes:

1.)
01 - Engine Electronics
038906019LA
1.9l R4 EDC G000SG 5405

Error:
17911
Generator Class Load Signal DF
sporadisch

2.)
03 - Brake Electronics
6Q0907379Q
ESP 5.7 font H03

Error:
18265
Last signal
sporadisch

3.)
08 - Climate/Heating Electronics
6Q0907044B
CLIMAtronic PQ24

Error:
00710
Motor for Defrost Vent - V107
sporadisch

Error:
01273
Fresh Air Blowers - V2
sporadisch

I assume that all 4 errors originate from the same source.
Can anyone provide more information based on these details?
Or are further details required?

Thank you in advance.
Mike²

Mike² wrote:

Or are further details required? ...

The MKB wouldn't be bad...

but the search function is throwing out the thread /viewtopic.php?t=1793&highlight=17911.

Error code 17911 is also mentioned:

Error Code: 17911
Generator terminal DF - Unplausible signal

Possible Causes:
Generator faulty
Voltage regulator failure
Circuit Interruption

Possible Impacts:
Additional heater not working


Therefore, if your onboard voltage is not correct due to a fault (see above), then the other errors are likely to be secondary effects...