Liebherr CNES 4013

Liebherr fridge service menu activation
press UP/DOWN and ON/OFF button simultaneously for several (4-5) seconds until service mode starts.
Press UP/DOWN until (left) fridge temp indication is on position 5 then press STAR
Now service mode is active (and remains active)
Press UP/DOWN to cycle through the service options
ie. first and second option activate valve
other options activate fan, light etc
If someone knows exactly what each option does please tell !!
Leave service menu by pressing ON/OFF button (short press) multiple times

During normal operation temp sensor fail will show as double bar