Location of tranmission fluid heat sensor - 2012 Hyundai Elantra

You may need the transmission rebuilt, once it starts to slip that is the end in mist cases. Have a local transmission repair shop confirm my guess on this

Pretty self explanatory

Do you have some type of code for that,
or concern?

Will most likely need a dealer to diagnose

sounds like over drive switch or transmision box

The transmission fluid is checked and added (if necessary) through the transmission dipstick tube

Having once owned a trans repair shop,
I would prefer you not flush the system

Due to the vehicles age ,and not knowing
if the fluid was changed every 30,000 miles

My Past Professional Opinion tells me your
trans is most likely slipping. ,thus over heating

You could check the fluid level but that won't do
much.

Your most likely are close to a rebuild situation

Figure about $1700.00

all inside the pan on the valve body you will see a block of switches then a seperate one they are called shift solenoids and a torque convertor lock up switch and a pressure switch make sure you have the right fluid for that trans also

CODE PO717 IS - A/T INPUT SHAFT SPEED SENSOR LOW INPUT CONDITIONS.YOUR INPUT SHAFT SPEED SENSOR COULD BE DEFECTIVE.CHANGE FLUID + FILTER IF IT HAVE NOT BEEN CHANGED IN A LONG PERIOD OF TIME.

The only "hoses" are the cooler hoses located on the front of the transmission.
Are you sure there is no leak coming from the Transmission Fluid Pan? These tend to leak first before anything.
Also is the Dip Stick/Filler Tube correctly inserted into the Transmission? Sometimes these are mistakenly taken out-of-place, and are not correctly seated, allowing new fluid to pour out.
The other place(s) to look are near and around the Solenoid (box-shaped on from of the Tranmission and around the Sensors. The Solenoid has a gasket that may be leaking. The Sensors have "O"-rings that also leak.
The best thing is to clean up any spilled fluid, jack-up and support the front of the vehicle and isolate where the fluid is comming from.

There is a rubber plug that is actually the dip stick. You can check out you fluid level but you have to crawl under the truck and remove the plug and there is your dip stick it is only a couple of inches long.

Is the check enigne light on?

If not then it could be a trans issue. Check the fluid again to make sure it is level. put the truck on level ground and with it running and in park check the fluid. Add fluid if needed to bring to level. Then test drive. If it still does the same check the fluid level after driving to see if it REALLY hot. If so it could be a sign the tranmission is failing.

Onyl other thing i can think of have you replaced the tranmission filter? if it was really clogged up it may, long shot, cause what you are saying as well.