What the code means

Whirlpool gives the likely cause of F9E1 on a dishwasher as a long drain: the water isn't draining out the way it should.

Before you start

Turn the dishwasher off. Unplug it, or switch off its breaker if it is wired in, before you take out the filter or reach under the sink.

Take out the filter and clean it under running water.
Follow the drain hose from the back of the dishwasher to the sink. Look for kinks, pinches and clogs, and check that it runs on the correct side and inside the frame.
If the dishwasher drains into a garbage disposer, make sure the disposer is clear. Run the disposer to clear anything inside it.
If the dishwasher is newly installed and drains into a disposer, check that the knockout plug was removed from the disposer inlet.
If your sink has an air gap, clear it as its maker's instructions say.
Look for extra suds. Dish soap used in place of dishwasher detergent makes suds. Turn the dishwasher off and let them settle.
Reset the dishwasher. Unplug it for thirty seconds, or switch off its breaker for thirty seconds if it is wired in. Then restore the power.

Stop and call for service if any of these happen.

The dishwasher still won't drain after all of these checks and a reset. Whirlpool's page for this code doesn't name a point to call for service, so treat a code that keeps coming back as that point.

Source: Whirlpool: F9E1 on a dishwasher; Maytag: F9E1 on a dishwasher.

Based on the manufacturer's support pages. Codes can differ by model, so your model's owner's manual comes first.