Transmission dropping to 3rd gear

Lately my 2001 Elantra has been dropping out of overdrive and back to
3rd gear at highway speeds. This happens occasionally, not all the
time. The condition is accompanied with the "Check Engine Light" going
on.

On most occasions if I stop the car, turn off the engine and restart -
it clears the condition (until the next time it pops back the 3rd
gear).

Is there an electronic module failing here or something like that?

Any help appreciated. Thanks.

 

take it to the dealer!!!

 

Find a dealer or a transmission shop with a computer with the capability
of reading the complete stored transmission codes.

It could be as simple as a sensor giving bad output, to a mechanical
failure in the transmission. Transmission problems have a tendency to
cause themselves to get worse (ie - $27 sensor failure causes the death
to a $350 planetary gear resulting in a $500 labor charge alone)

Hopefully its something simple and cheap (or covered under warranty)

JS

 

If the computer sees a fault, it may put the transmission in failsafe (3rd
gear only). Turning the vehicle off and then on again should reset the
failsafe.

A check of the ECM (engine control module) and TCM (trans control module)
trouble codes should provide a hint as to the cause. The most common
culprits are the input and output speed sensors.