I don't know if this is a rook question but i just got this lift truck almost a year ago and it started this week with a Multi-purpose warning icon followed with the check maint. manual symbol with another symbol on top of it that i cant find in the manual. No codes other than a couple of f-16s. The indicator is a clear drop with a circle around it and two curved lines on the right and left of the circle. Any help will be greatly appreciated.