Consumable indicator spinning

next to my problem posted yesterday with the late switching point at only 8000, my consumer indicator seems to have hung up. Since the battery was off, the consumption indicator shows only 0. After the start when starting the display worked in the first moment then the displayed consumption continuously became smaller and remained hanging at 0. The car has an LPG conversion, however, the error occurs exactly as with the shut down gas system. I'm afraid I'm missing the manual. So if someone has a hint – possibly. I would also be grateful for the late switching point.