Dishwasher - Cycle Indicator LED Lights
Generally speaking, electronic control models have light emitting diode (LED) indicators that take extremely small amounts of electricity. The lights go off after a period of time if the dishwasher is not started. Pushing any button or opening and closing the door will re-illuminate the lights. If the dishwasher was started, the lights will remain on until the dishwasher door is opened at the end of the cycle.
It is best to refer to your Owner's Manual for information about light operation because the light features are model specific.