What part does The TAC(Tac Module Throttle Actuator)play in truck performance? on 2003 GMC Sierra 2500 HD

Truck recently cut off when making a turn got 2 boost offs and barely made it home, carmd says throttle actuator motor CKT 1 is open shorted to ground b and throttle actuator motor Ckt2 is open ,shorted to ground b throttle actuator motor is damaged or has failed. throttle actuator motor control motor has failed.What would be the solution? Diagnois P1516 and condition for setting code is DTC 1518 not set,keyin crak or run mode, ETC saver Mode, the the ETC/TAC module detected the position were not within a calibrated range of each other could not determine the throttle position

Asked by for the 2003 GMC Sierra 2500 HD
Did carMD offer a solution? Sounds like a mass air flow sensor/, OR a throttle position sensor problem which is part of the throttle body assembly. Or the circuit. See a carMEchanic and let him check it out, may check for tsb.
Thanks for the help will do
2 answers 1 comment
Throttle is fly by wire with 2sensors one on firewall one on the throttle body. If they're not in sync truck will usually say reduced engine power.