Before we call in the service guy, any chance anyone has seen these alarms and has info on what to look for?

PL0044#2044 - Lubrication Troubled

PL0172#2172 - Grease Lubrication (alothugh the grease is 3/4 full currently)

Back ground is that we purchase this machine used last year (only had 100 hours on it). We've been running wit this alarm for a little while and it finally clear itself, only to come back on. All of the lubrication seems to be running fine. Must be a couple bad sensors, but where to look?

Thanks.