My dish washer drain pump stopped working. I replaced it. However now, the drain pump runs continuously.It won't stop even after the end of the cycle.

When I start the cycle, I hear washing gushing sound followed by motor start sound. At the end of the cycle, I still hear drain pump sound. The only way to cut it is to power off (at the switch board) or open the door.

What could be the reason? Is it control panel mal-function? or something else?
Appreciate, if someone can post any trouble shooting tips.

Thanks,