Rear wheel drive vehicle with 3 speed automatic transmission would not shift into 3rd gear at times.  I took it to a transmission expert which dropped the pan, changed the fluid and found nothing wrong.  Over the next two years the car started to do the same thing more often.  I called around town and talked to several shops.  Not one of them was optimistic that they could come to a quick answer.  I really did not want to drop my car off at a place only to have the fluid changed again and pay them $100/hr to try and trouble shoot the problem.  That’s when I woke up and decided to simply search the problem using the www.  I immediately found a forum with the exact same problem posted.  Great discussion.  Lots of personal stories.  Finally pictures were posted with a solution that worked.  I immediately went out to my car and disconnected the top sensor next to the fuse  box as described in the forum posting.  Problem solved.  Don’t fall into the trap of solving things the “old fashioned” way.  Searching the WWW has to be included in your problem solving.  The old ways of calling around town simply doesn’t work as well.

Here is the forum that I found.

This next link even had pictures.

Simply disconnect the plug on the connection number 1 in the picture below.