Saturn won't shift into 3rd
 

Hey guys I'm new here but am hoping someone can help me with my problem. I have a 2006 Saturn Ion that used to belong to my mom before we lost her to cancer. Anyway when it was given to me I found that it won't shift up from 2nd gear. My brother said he had taken it to the dealer and was told it needed a "shift soloniod" . He said they would replace it for $500.00. Well I have a friend who works as a mechanic who was willing to do it for a little less. And being the cheap B*#! that I am... well I paid my friend and we replaced all three soloniods in the transmission as well as the filter and fluid. Needless to say it still has the same problem. Here's the tricky part.... when driving the car I won't go above 4ooo rpms as to not stress it too much and it's just in town driving. But when driving the car will "all of a sudden" Oh yea the odometer says "Prw Str" all the time. Anyway when driving the car with no set pattern the door locks will simultaneously lock, the odometer will go to the correct mileage, and the transmission will shift up. And if I keep my foot on the gas pedal and "not" let it off it will stay shifted and I can drive it like its normal. But if I'm slowing down when this occores it will shift back down and go back into the "won't shift mode while the odometer goes back to Prw Str display". I'm at a loss right now. ($400.00) dollar loss. I'm thinking maybe theres an grounding problem, but I really don't know where to begin next. Any help would be great because this is the only car I have my truck is down and going in the shop. When it rains it pours.