I recently bought a 2006 Nissan Murano with 130K from a friend for cheap. The alternator went on the car 6 months ago and he didn't want to deal with it. The car has been sitting in his driveway since. I had the car towed to my house and fixed the alternator and the car runs great. The problem now is that I'm showing codes P0840 and P0845 "transmission pressure sensor A and B circuit". When I drive the car I notice it struggles to get up to highway speeds and the tranny almost sounds like its whining and runs at about 4-5K RPM at 60 mph. Other then this problem the car runs great and is spotless inside. Id hate to have to junk it. I don't believe my friend was hiding a problem from me but its very strange that the car would run fine, sit outside for 6 months and then all of sudden have a bad tranny. And stranger yet when I first started the car it had no check engine light on. It only came on after I drove it a little. Is it possible I have an electrical issue? Maybe a critter made a home in there and chewed a wire? I could really use some advice other then replace the tranny.