On a Dodge Neon 2000 what is engine warning light code P0743?

P0743 is for a open or shorted circuit. It means either a it is not grounded or that a wire has broken or something has come unplugged. It is most likely underneath the car. Check the wires around the transmission make sure they are all connected. I hope that this helps you.

true code definition: P0743 Torque Converter Clutch/Solenoid Trans An open or shorted condition detected in the torque