T4 AJT ESP Issues: Troubleshooting & Solutions

"Hi, I have a VW T4 Caravelle from 2002 with the AJT 2.5 TDI engine. My problem is that the car was heavily smoking black during driving and then stalled. Since then, it hasn't started properly. I've been able to pinpoint the source of the problem to the mass airflow sensor. Here's my issue: I can see the target value in function block 02 and observe how it changes when I adjust things. In function block 019, which shows the initial values, I should have 1 volt and 5 volts, but instead, I only get 1 volt on both readings. VCDS reported an error code: "mass airflow sensor - lower limit."
Can someone help me with this?

[Translating...]

Autoscan?

I'll send it over later.

It's not showing me any errors right now.