Checking keyswitch contacts:
Unplug dishwasher or disconnect power.
Remove connector P1 from the control board.
Using the table below,
measure the resistance across the switch when the key is pressed.
NOTE: The meter must be connected with the proper polarity.
This test will not work on models with a “touch sensor” type user interface.
The resistance reading should go from infinity (open circuit) with the key open
down to a readable Ω level with the key pressed.
The level may be different depending on your meter, since there is a diode in the circuit.
If available, you could use the “Diode Test” function of a digital meter,
which will give a voltage to turn on the diode in the circuit.
➔If any switches fail this test, replace the console panel/keypad assembly.
➔If all switches test OK, replace the machine control board.
click on picture
Source: Maytag mdb6709aws0 dishwasher inop.