I own a Whirlpool Dishwasher Model DU920PFGB4. The only wash cycle that works is the HEAVY. The rinse and the remaining buttons do not work. Sometimes when it is running on the heavy cycle, it appears the washer clicks on and off slightly, however it continues to run ON THE HEAVY CYCLE… PLEASE HELP. My wife is expecting to be washing dishes soon…
Here are your parts
http://www.appliancepartspros.com/partsearch/modelsearch.aspx?model=DU920PFGB4
Here are a couple manuals and a tech sheet
http://www.servicematters.com/docs/wiring/Tech%20Sheet%20-%208051291.pdf
Often this type of fault is the keypad (console). Can also be the control board.
The usual way to troubleshoot is to check the keypad with a meter, if OK then it is usually the control board. Unfortunately I cannot find keypad pin-out information. Try the connector cleaning below.
Also try to run the diagnostics on the tech sheet.
Also check that the wires that go from the control to under the unit are OK.
Connector Cleaning
Unplug the unit
Open it up
Remove the ribbon cable from the keypad to the control board at the control board.
Clean the edge connector.
If it is the type where there is not a connector just the insulation is removed, it can be cleaned with a pencil eraser. Do not use an ink eraser as it is too abrasive.
Check the tracks in the ribbon cable for hairline cracks. A magnifying glass helps here.
Would not hurt to clean the connector on the board. Use electronics contact cleaner or isopropyl alcohol and a tooth brush. Be gentle and do not reconnect till all the solvent evaporates.
Reconnect everything and give it a try.