P1127 Lexus code-I have new TB and ECU installed but no current to circuit.

Question

1999 lexus GS300 in limp home with vcs and vcs off lights on. Just had Lexus dealership install new throttle body and ECU. Still get code P1127- Actuator Power Source Circuit Malfunction. Dealer said was a bad wire. Want $625 to find and repair. Is it really that hard to do? I can't find any info on this except that P1127 circuit description and wiring diagram and I don't know how to read that thing. Anyone out there that has fixed this circuit? They said the connections where good, it was in the wire somewhere. Help would be greatly appreciated.

thanks,

Dan