A customer's ice machine is acting out again. Prodigy series air cooled unit mounted on a soda dispenser/ice bin. The last two errors are code 2, max harvest and code 8, short freeze. The tech literature is not specific as to what triggers these codes Any suggestions?

I have cleaned the machine quarterly for the last 2 years, most recently 3 weeks ago. The only other issues it has had were bun door switch and water inlet valve, both over a year ago.