2001 Sunfire Auto is slipping

[haulincats]

My daughter has a 2001 Sunfire 2.2 with an auto. The trans started slipping
really bad. I have no idea where to start????
It has 150,000 miles. It has never leaked fluid. I am told you cannot
check the fluid, that you have to take it to a dealer.
Another guy said there is like 27 electronic things that the computer tells
it. I am very mechanical. I have had engines, trans, ect. pulled and put in
in trucks and Jeeps but never have worked on a front wheel drive before.
Please Help?????
Thanks,
Vance

 

[melsg5]

the car has a plug in the side of the transmission case. It has to be up on a lift, level, and the fluid should be even with the plug hole. Change the fluid and filter to see if that solves the problem. The service should have been done no later than the 100,000 mile point