On some models the power seat can become inoperative when a cable becomes detached. Replacing the cable will fix this issue.Google+
Car Problem Reports
Honda Odyssey Power seat failure due to detached cable
Honda Odyssey Problem
Average Mileage: 125,000 mi (120,000 mi - 130,000 mi)
Visitor, 2003 Honda Odyssey, 130,000 mi
The plastic cover holding the control levers has been loose and dangling for awhile. Eventually, the cable became exposed and we were moving the seat by wedging fingers between the plastic, directly touching the controls! Now, something is busted off the cable and we can't move the seat. At all. Have to figure out a solution.
Don't wait that long! If the plastic housing around the driver seat levers is loose, replace immediately!
Visitor, 2003 Honda Odyssey, 120,000 mi
Detatched cable/ worm drive type mechanism