I have a Whirlpool ADP7966 dishwasher that keeps displaying the error code F6.
When a normal wash cycle is selected, it will run to the end of the pre-rinse before the F6 error code appears and the cycle stops.
On a glasses or quickwash cycle, it will run to the end of the wash cycle - the F6 error code then appears and it will not proceed to the rinse and dry stages.

Colin Andrews, February 2010