Brother PDuff calls the dance steps on this little ditty:

Remove bottom access panel and check main control for any lit leds. Lit led is specific to affected component. Access Component/Relay/Triac test as follows:

From power up press Sanitize and Delay Start

"Et" should be displayed (engineering test)

Press Rinse Only

"rt" should be displayed indicating component test mode. Press the following buttons to toggle on/off each component:

Auto Sense-washer motor

Heavy-water valve

Normal-drain motor

Quick-drain valve

Rinse Only-Clean light led

Hi Temp-all leds on control housing

Sanitize-fan state

Air Dry-dispenser

When checking heater, always fill tub with water.

Source: Frigidaire D/W EIDW6105GB1