Manual or automatic. With the little information that I have I would: 1). Check the fluid level. 2) solenoid valves is what shifts the gears so I would check the wiring to the valves, I imagine there is a wiring diagram that would show you the details. 3). It could be the transmission control module so I would check for power and possible wire damage. Sorry that I am not much help on this one and you probably have already checked these items. Good luck and let us know what you discover. Cheers
