How do i check trans fluid - 2004 Saturn ION

check level of trans fluid - and level of coolant --old coolant can be brownish -- if it is trans fluid and level low possible trans cooler if internal in radiator can get into coolant but check fluid to make sure --

It doesn't have a dipstick because checking trans fluid isn't as simple as just pulling the stick and reading it.
Trans fluid level varies greatly with temperature and tolerances in today's transmissions are very close. If fluid is overfilled by a small amount it can raise up into the geartrain as the trans warms, the fluid churns and ingests air and the transmission fails. Simply overfilling the trans can lead to complete trans failure.
To get an accurate fluid level you have to use a scan tool to check the actual temperature of the trans fluid. Once the temperature is taken then a chart is used to see how many millimeters of fluid should show on the stick, and then a special dipstick is used. The stick has a stop that seats in a certain way depending on vehicle, and it's labeled in millimeters.
If you don't have a trans leak and no repairs have been done then your fluid is full and checking it is never necessary. If you do have to have the fluid checked then a shop with the proper equipment can check it for you in a couple minutes.

This info was copied from another site: 2007 Jeep Liberty you check atf when it did not come with dipstick

He either added the trans fluid to the engine oil or he is checking the wrong dipstick. CHECK THE ENGINE OIL LEVEL to see that the trans fluid is not in the engine. If the engine oil is full of trans fluid, do NOT START the car and now you need to change the engine oil and also add the trans fluid to the trans. If engine opil is ok, be sure to find correct dip stick for trans fluid. They should be marked accordingly.

Disconnect battery > remove driveline> catch fluid with container
that may come out rear shaft or use a shaft fluid cap > remove torque converter bolts> remove housing bolts that connect trans to
engine >remove cross member use floor jack or similar to lower trans don't forget to remove dipstick assembly. Some trans have
a drain plug if so drain fluid prior to removal.install is reverse fill with factory GM trans fluid not aftermarket.after filling shift into all
gears twice check fluid in park or neutral if okay then check for leaks if no leaks lower truck and test drive check fluid once more
on level ground.
Good luck on your journey.

don't know if your vehicle even has a trans temp sensor. if it did it would be located internally inside the trans pan in valve body. check your trans fluid level, color, and smell. worn trans fluid will cause trans shift issues. burned trans fluid is an indication your clutches are burning and slipping.

check fluid level in transmission.

when you check the fluid do you allow the trans to come to operating temp and check it with the engine running and trans in neutral, don't forget to set your E-brake or block the wheels from rolling. you checked the fluid in this manner it would be my guess that the clutches inside the trans or the belts in the trans are slipping, it could also be something as simple as needing a trans service, new fluid and filter.

Hello
What happened is the tube that goes thru the radiator sprung a leak and coolant is getting in the trans and visa-vera so the answer that you got is 100% correct. But you have to change trans fluid and coolant and do NOT drive or you will be buying a new trans. Thanks

Any high quality brand name trans fluid is fine. I have a preference for Quacker State.

do not do trans flush if car has over 100,000 miles and has never been flushed. if its under 100,000 or has been fushed before it is an easy job. there is a drainplug on trans pan. take out drain fluid. new trans filter will come with new trans pan gasket in most cases. remove trans pan, fliter is behind trans pan