When I asked Kia dealer to change tranny fluid they claimed it was completely sealed and could not be changed
2016 Sedona???
That's not true. The fluid change on my 2015 Sedona (same as your '16) was relatively easy, same as a Sorento which also uses the same 6 speed transmission.
Drain plug on bottom of the transmission gets the fluid out. There's a plastic screw cap underneath the battery (on top of transmission) that serves as the fill port. To check the fluid level when you're done, there's a plug on the front side of the transmission (in the plastic side pan) you unscrew, that serves as a check port. So no it's not as easy as older transmissions that had a simple dipstick, but plenty easy enough.
The basic steps go like this:
Open fill cap, drain fluid via drain plug. Reinstall drain plug, measure what came out (pouring the drain fluid into single quart bottles is an easy way), and put that amount of fluid back in to get you at a ballpark level. Close fill cap and then start the vehicle and either drive it, or let it sit (will take much longer) till the fluid gets to the appropriate temperature-- I don't remember what it was exactly (it's in the service manual or someone here on the forum can hopefully fill this in), but it was around 140F if I'm not mistaken. At that temperature (give or take), check the fluid level with the engine running and vehicle in P or N by opening the side level check plug. Do this on a level surface. You should see a very slow stream or dribble. If it's a fast stream, let it drain out until you get there. If nothing comes out, add fluid until it does.
As far as reading trans fluid temp, any cheap $20 bluetooth OBD-II scan tool with appropriate Iphone or Android app can tell you this. On Iphones I use an app called Car Scanner and on Android I use an app called Torque Pro.
