When the SYSTEM MONITOR LIGHT comes on, what does that mean and how do I fix it?

What is your question?

As I was driving up a low grade hill tonight, I felt zero aceleration power but yet the car was still moving! I stepped on the gas, I didn't speed up but yet I made it up the hill. I notice the RPM gauge reved up at this time. I felt like I was coasting the rest of the mile ride home. Stepping on the gas pedal didn't make a difference in the speed that I was going but yet I was still traveling down the road. As I turned into my subdivision which has a much higher grade hill, I shifted to 3rd (I don't know why) and made it up the hill just fine. Please help me...what do you think? L.