found that it is directly connected to the Skid Control ECU with Actuator, starting with GEN 6.5. It is on pin 15 (WFSE) (only if it is TMC made, it's an AVICS system) US systems are BOSCH and do not have that reference, that i have found yet. I have not found the meaning of the acronym(s), yet... I will keep looking. Update; I looked through the repair manual and could not find the explanation (decoder ring) for that WFSE acronym.
It stands for write flash enable.