Yesterday afternoon my 2005 EX-L's passenger side power sliding door decided not to work, for no apparent reason. It worked two times earlier that day, no problem. On the third time of (attempted) use, however, it didn't budge under its own power when either the remote was used, or the exterior handle was used to try to make it open. I was able to get my daughter into the van by opening the door manually, so we weren't completely "dead in the water" because of this failure. Also, the "slide door" light was lit on the dashboard ... owner's manual says this indicates a failure in the power sliding door system, and to turn the switch off on the power door switch panel and take the van in to the dealer to get it checked out.
When I tried to initiate the door opening initially using the remote, it didn't clunk, bang, or indicate a breakage of any hard parts in any way ... the door just simply did nothing. We did have cold temps ... approx. 10 degrees F, but no rain or snow, and I didn't take the van through the carwash anytime in the past 3-4 days, so I'm confident "frozen water" didn't cause this failure. Also, the driver's side power slider door worked as it normally does, so whatever happened was limited to the passenger side door only.
I found out from the owner's manual that there are individual 40 amp fuses - one for each power sliding door - in the secondary (smaller physical size) fuse / relay panel under the hood - the one for the passenger side door checked fine, so that wasn't the problem. Also found out that there is another 20 amp fuse for the passenger side power sliding door in the fuse panel inside the van, near the front passenger "kick panel" below the dash. This one also checked out fine.
Going the the Honda service manual, I went to the power sliding door section, and found a section that describes "homing" the power doors in case of failure or a power disconnection, and decided to give it a try since I didn't think anything physically was broken, and no fuses were blown. The service manual says to pull fuse #7 (7.5 amp) that is in the driver's side fuse panel (near the kick panel below the dash on the driver's side of the van) to clear the error message on the door control unit, then plug the fuse back in. Then, with the key to the "O" (i.e. off) position, and the switch off on the power door switch panel, open each door completely (manually), then close each door completely. Next, turn the ignition to "on" (but don't have to start the van), and slide the power door switch to "on", and see if the doors open / close as they normally should do.
In the case of my van, this cleared the "slide door" indicator on the dash, and now both doors work as they normally do. I have no idea what caused the passenger side door to stop working, or how long this "fix" will last, but it's working at the moment. All I can say is if one of your doors stops working, it's worth a shot at doing this "clear / rehome" procedure before taking your van in to the dealer, to see if it clears the problem. Maybe this is the "control / alt / delete" alternative for the Odyssey's computer system .... !?!?