To reset a Kenmore Elite 665 dishwasher that is stuck in testing mode, you can try the following steps:
Open the dishwasher door and locate the "Cancel" or "Cancel/Drain" button on the control panel. Press and hold this button for about 3 seconds.
If the dishwasher doesn't respond to the "Cancel" button, try turning off the dishwasher at the circuit breaker or by unplugging it from the power source. Leave it unplugged for approximately 5 minutes to allow the electronic control board to reset.
After the waiting period, restore power to the dishwasher by turning on the circuit breaker or plugging it back in.
Close the dishwasher door and check if the testing mode has been exited. You can do this by starting a normal wash cycle and observing if it proceeds as expected.
If the dishwasher continues to be stuck in testing mode or exhibits other persistent issues, it may require further troubleshooting or professional assistance. Consult the dishwasher's manual or reach out to Kenmore customer support for specific instructions or recommendations tailored to your model.