Hello and thank you for using Just Answer
the code is for the damper clutch solenoid.
it can be bad wiring a failed solenoid or a bad TCM (transmission control module)
a transmission shop would be best suited to test the solenoid for you but you may try a general repair first
you will need to have the harness and solenoid tested
let me know if you need more help
click here for more information on your code p0743
they solenoid is mounted on the valve body inside the transmission