To diagnose the problem I pulled out the dishwasher from the counter and ran it until E15 code appeared while looking underneath for source of leaking water. The water was leaking around the sump where it mates up to the bottom of the dishwasher. The youtube video provided an excellent tutorial on how to replace the sump, so I went ahead and ordered the replacement from AppliancePartsPros.com and followed the instructions in the video. The project was very doable with a little bit of time. The dishwasher is working fine now with no more leaking or error codes. Thanks for the quick delivery (2 days) of the replacement part and for excellent youtube video instructions!