Honda Odyssey Sliding door does not close

An update. I took the car into my dealer. They checked and said that the track on which the roller for the sliding door moves had a small bent. This was causing the sensor to think it had it an obstruction, and that's why it kept on closing and opening. They had to replace the whole roller assembly and this cost ~$400.

@SP0ck - did the fix at the dealer help? I did the same thing and am having the same issue. My dealer wanted $400 to fix the middle roller, but I replaced that myself and the door is still acting the same way. Did your dealer end up replacing anything else? Thanks!

Sounds like there are different kinds of problems here. On our 2008 Odyssey, the doors have been jerky and sometimes wouldn't close, especially if parked on a slope (either uphill or downhill). Today I took a can of WD-40 and just sprayed all the rollers and tracks I could see and hit -- front/top, front/bottom, and middle/back. The middle back seemed especially helpful -- just squat down and spray up through the slot in the body to get the spray up onto the track. Then I opened/closed several times on a level grade. Both sides working fine now, except if the car is parked on a steep downhill they won't open completely unless given just a little manual assistance from the outside.

most likely your issue is a broken sliding door roller. Causes clanky door motion when using motor (mine at times would act like it hit an obstruction and self close) and you can feel spots of resistance when opening manually. Theres a good youtube video on replacing roller assembly yourself. Cheap part and about hour fix to do yourself.