Service Engine Soon Light

What is your question?

I am not sure if this is the actual problem but the Service Engine Soon light is on and I took it to a place that put a computer on it and told me that it is indicating that it is the Starter Switch or maybe the transmission.. Not sure how the two are related, but the car starts.. I have noticed lately that it seems to stay in 2nd gear a little longer than usual.. there is a little bit of a drag on it.. But also I have been running the AC more because it is hot here.. I bought the car in 2006 with about 50,000 miles on it and I only drive 20 miles a day at most and occasionally take a road trip.. So I am not sure what would cause the transmission to give me problems. I keep up with maintainence and oil changes too.. Can anyone give me an idea... It is 2 wheel drive auto trans.. only about 80,000 miles on it now.