Hyundai: 2001 Elantra Xmission

As I pulled out of the Albertson's parking lot, my 2001 Elantra GT automatic
suddenly decided not to shift gears. At the same time, the "check engine"
light came on steady. After turning the engine off and then restarting, the
light was off and the car shifted fine... until about 5 minutes into my next
drive, when the same thing happened.

Does anyone have a suggestion for this? Because the check-engine light is
involved, I'm inclined to think it's an electronic problem vice a mechanical
one, but perhaps hyundaitech can help....

--P

You'll have to have it scanned to see what the code is, but the most
popular is P0715, input speed sensor.