I have a 1999 Elantra with an automatic transaxle. The problem is it seems to be stuck in third gear. The unit will not downshift at a stop & I have to rev the engine like crazy to get going again, it also will not shift into overdrive & at 50 or above the revs start to get really high. I can get the unit into second by shifting it manually but it will not drop into low no matter what I do & it will not shift at all on it's own. If this was one of my older American vehicles, I would start by replacing the modulator valve but my Haynes manual doesn't even reference this part. It may not exist at all in newer models as far as I know. Any advice in rectifying this situation would be greatly appreciated as I absolutely rely on this vehicle & I am desperate for a fix. Thanks in advance.

 

on these veichles there is a fail safe mode or get home mode which when a fault is detected in the transmission the trans ecu locks the gears into 3rd to prevent further damage. get down to your local dealer and get them to plug the diag in . usual faults are dodgy input/output speed sensors.