Tough call. Heres how it works:
Timer sends power to temp switch and switch sends power to the water valve. I'd start by checking for power at the hot water solenoid. If power is present (120vac) your valve is bad. Next would be the switch. Determine which two contacts should be closed when hot water is selected by looking at the wiring diagram. You should have a closed curcuit (continuity). If not your switch is bad. If that tests good replace timer.
I should note this info is generic. I didn't look at a wiring diagram for your washer. I think the three parts I mentioned are the only components on your fill curcuit, but cannot confirm. I hope this helps.