general problems of the 2009 Nissan Pathfinder

The vehicle just stop. Had tow to the mechanic diagnosed with coolent in that damaged the transmission.

When driving uphill on long mountain roads and shifting the automatic transmission down to 2, 3 or 4, the car won't stay in gear. After a few minutes of driving it will shift by itself into 5 without allowing you to shift down again. You can only go into d or stop and shut down the engine. The transmission shop already replaced the shifting assembly, inspected the entire transmission & wires from the computer. No problem could be identified but the issue remains. The car will stay in lower gears when driving downhill. It's a mystery and very expensive to diagnose further. Do you have any ideas? the local Nissan dealer is unable to help. They worked on the computer and main circuit boards about 5 yrs ago � could the have possibly caused this problem? any help would be appreciated.

Was on my way home and truck lights came on transmission started jumping and all lights came on . . . Parked car would not crank the next day ,,, called and had towed. Was told by Nissan that transmission and radiator was not any good and it would cost me $4800 to fix . . . No one offered to help . . I was told that I could contact Nissan so I did , was told by Nissan that it was to bad that I was past the extention of the warenty of the truck. And they could not help at all. . . . And hung up. It cost me $3800 to repair my car. . I feel ripped off, and will most likley never buy another Nissan again even though I have owned 3.