Agreed w/ above post on removing the fill hoses (especially cold) and examining the inlet screens for blockage.
I recently troubleshot a model AWN412 with a "bad timer, stops at rinse cycle" that had a blocked cold inlet, rust from the plumbing. Hot fill screen was fine as the water heater catches all the rust upstream.
Diagnosis was simple: start wash cycle on HOT, good fill flow, move temp to COLD, no fill flow. Rinse is all cold on this model, so after spin cycle it just sat there waiting for the water level switch to close...which it never did as no cold water was flowing.
Easy fix to remove and clean the fill valve, only parts needed were new fill hoses as the old ones were rubber and way > 5 year old safety window. Told the guy to have a plumber add a cartridge filter on the main supply line and buy plenty of cartridge kits, and have the hot water heater flushed afterward.