Speed control problem


Hi there, i´m new here. My Name is Michael and i´m live in Germany. My ride is a Navigator from 2004 and i will start with my problem:

Since a few days my crusie control is w/o function.
I am very to grow desperate. Thats what i tried:

  • entering self test, everything --- passed
  • measured the resistance and voltage between spring clock and PCM --- passed
  • measured voltage and resistance between PCM harness and ground --- passed
  • measured voltage and resistance at servo control --- passed
  • checked the switch at brake pedestal --- passed
  • checked mechanical parts like control cable --- passed
  • connected a VCM via OBD2 and read the DTC, was clear

Anybody has an idea, what can it be? It is very, very important for me.
Thank you so much for help