Water naturally run downwards so the pump will need to be at the very bottom of the machine.
In some machines you can access the drain pump from inside the washing chamber - right at the very bottom under the filters is a sump - in the bottom of the sump you may find a little plastic cover held down by a single Torx screw - under the cover is the drain pump impeller.
Sometimes it gets jammed up with food debris and lemon pips - tweezers help.
Peccavi, February 2013
