Might help for future issues:
[B]I think you reset the door[/B]: How to Reset an Electric Sliding Door on a Honda Odyssey
By Leonardo R. Grabkowski, eHow Contributor , last updated February 19, 2012
Print this articleThe electric sliding doors (called power sliding doors by Honda) on your Odyssey van [B]may need to be reset from time to time,[/B] [U]particularly if the battery is replaced or disconnected for more than a few minutes.[/U] If your power sliding doors are not functioning correctly, either by using the door switch or the keyless remote switch, try resetting them to see if the problem is corrected. If resetting the doors does not fix the problem, there may be other problems with the power sliding door mechanism. See your Honda dealer for assistance.
Instructions
1 Reconnect the Odyssey's battery, if it is disconnected. The power sliding doors will not reset without the battery connected.
2 Turn the ignition on. Move the power sliding door switch to "Off," then move it back to "On." This switch is located to the left of the steering wheel. It's labeled "Main."
3 Press and hold both power sliding door buttons until the doors close completely. If this does not work, turn the "Main" switch to "Off" and manually close the doors, using the inside or outside handles. Turn the switch back to "On." The power sliding doors will reset and their normal functions (including keyless operation) will resume.
Easiest thing first: Clean the door contacts. Clean with a pencil eraser, contacts on the door pillar and door, lube with WD40, and then wipe off the excess. Sometimes this solves the problem just caused by dirty contacts.
Tech Bulletin: [url]http://www.hondalac.com/service/Bulletins/x99-028e.pdf[/url]
Other possible issues if problem recurrs according to the Manual there are 4 possiblities causing the buzzer to stay on:
1) Junction switch dirty or misaligned
2) Full Latch Switch failure (is your closer motor activating after door slides to close down the rail?)
3) Poor pin connection or open ground in ground circuit for Full latch switch
4) Ground G551, 552 or 581, 582 may be loose.
5) Component failures that cause the door to not work properly include, faulty fuse, or door control unit, or a faulty multiplex unit. Try a new fuse, and if that does not work, may be best to have a dealer test the other 2 components.
I would have answered sooner, but I charge double time for Sunday work. Wanted to save you a feel bucks buy doing this on my bosses time. :-)