Electrical problems, battery keeps going dead over night.
Transmission problems, van is on third transmission.
Sliding doors seal to the body in hot weather, cannot open them, have even broken door handles trying to get open.
I have owned two domestic mini vans previous to the Odyssey, I took a large loss on both when selling them. I thought a Honda would retain more value over its life, so I bought the Odyssey.
It has been a mediocre vehicle as long as I have owned it. It started having transmission problems at 65,000 kilometres, not shifting at all eventually. I had always had all the service work and oil changes done at our Honda dealer so they replaced the transmission on warranty, I paid the bill for the next Transmission at 130,000 kilometres my self ($3500) and it is on the way out again. I see that there was a recall on the transmissions eventually, but I did not qualify as I had too many kilometres, be prepared to replace transmissions every 60,000-70,000 kilometres.
The sliding doors have been a problem since new, if you spray the rubber seals with silicone every couple of weeks it helps to stop them from sticking.
I have replaced the Battery almost every year that I have owned the van, but that only seems to work for a month or two and the battery starts going dead again, the dealer is unable to find a problem with the electrical system.
Overall I have been disapointed with Van, but the good news is the resale value has remained very high.