Toyota Sienna CE - Manual Sliding Doors Won't Open

WD40 _{(other spray-on lubricants are available)}?

Toyota Sienna Sliding Door Problems - Car Forums - Edmunds
2005 Sienna sliding door stuck CLOSED - Tundra Solutions
2005 Sienna manual slide door jammed - Toyota Nation Forum ...
Many more on the net.
Just Google: "toyota sienna sliding door stuck closed"

Frozen Water makes the door gasket stick to the body. I carry an all plastic tool for automotive body work, for prying door panels loose, that is thin enough to fit between the gasket and the body. Breaking the ice seal frees the door to open. In a pinch, a credit card will do it but the card's magnetic strip might be damaged.

The thing you didn't mention is whether the key or fob actually operates the lock mechanism? Is the problem that the lock doesn't work, so that it blocks the latch mech, or does the lock work fine?

If the lock doesn't operate, it needs to be dried out and lubricated.

If the lock unlocks with the key or fob, then your problem is either in the latch mechanism, or the door gasket is freezing to the frame. The latch can be fixed by getting in there with water displacement agents (WD-40 and its cousins) followed by proper longer-term lubricants (see mfr's specs). The gasket problem might need come cleaning of the door frame, and maybe coating with something that will repel the water (silicone?).

Start working away at the possible causes, and eventually you will get there.

Thanks for the detailed reply.

When I unlock with fob or press the lock / unlock button at the driver's door or use the key on the passenger side door, the locking levers on the sliding doors do move from lock to unlock state ... and also you can hear clearly the sound of their movement.

As I am driving sienna for the first time, I don't know what exactly to lubricate and how to access that area.. most probably some sort of gasket.

Day before yesterday, I was standing in a parking lot and saw a gentleman with sienna struggling with his sliding door.. He shook the door so hard that the car itself was shaking slightly but within a minute the door opened and before I could talk to him, he moved. I wonder if that's the right way to open it..

I'm not familiar with the Sienna specifically, but if it's like most minivan doors, most of the latch mech is right at the trailing edge of the door, where it catches the Nader bolt or latch loop on the door frame. If you have your spray lube, you can stick the nozzle in there and spray around.

Does your door sag any when it unlatches? Maybe it is putting some tension on the bolt, so that it won't unlatch freely. I've seen that in older cars with long, heavy doors, that the hinges get bent a bit over the years and sag, leading to latching problems. My wife had an Olds Starfire with that problem - a couple of times I put a piece of 2 x 4 and a bottle jack under the edge of the (open) door, jacked it up and jumped on the door frame to bend the hinges the other way. I can't imagine a minivan door doing this, but it depends on how the slide mech works. There may be some part of it with bolts that you could loosen and retighten in a different position.

The guy you saw may also have been trying to shake/rattle/roll the door enough that the ice on the gasket cracked and it opened. Get some silicone spray lube and wipe it on the rubber edge gaskets, or even better, some parrafin or beeswax. That way the water & ice won't stick to the gasket. It can't hurt to do this even if it's not the problem, and easy to do.