transmission takes off in 2nd and won't shift into overdrive 2.5 engine
Have you checked your transmission fluid level?
could it be shift solenoid bad
Sensor issue then. Randell is correct to suspect a bad sensor.
Looking for a Used Sonata in your area?
CarGurus has 50,904 nationwide Sonata listings starting at $1,995.
Search Hyundai Sonata Questions
Hyundai Sonata Experts