I have a 2003 range rover and just had the trans fail safe program warning come on while driving on the freeway. Shifted into maybe 4th gear? wont down shift from there. Shifts smooth and have not had a problem with it until now. All gears still work and no lag between shifts while driving. Any suggestions as to what it could be? I am at a complete loss... Im guessing electrical problem since mechanically shifts fine into all gears? HELP!