I have 2003 jeep grand Cherokee Laredo. Today the transmission started doing some things. It won't shift out of first till 3500 rpms, the rest of the gears are fine. If I turn the jeep off and start it back up, I don't have first gear at all, I start off in second. These two symptoms change back and forth every time I turn it off and start it again. Please let me know what's possibly going on. Is it a computer problem, or do I need a new transmission?