ECL power control cables
I can't find anything that suggests the ECLS can't control the FMM even in auto mode. if electrical power is lost to the collective auto/manual switches, the solenoid should release and revert to manual mode.
Within the FMM, as long as the engine is in AUTO GOV, the ECL rode end is not in contact with the metering valve control arm, but it's following it closely.
At the switch over to MANUAL GOV, either automatically (EEC failure) or selected by the pilot, the engine power setting does not change, but internally to the FMM the ECL rode end is now in contact with the teetering valve control arm. The pilots can then adjusted the ECL, and then the engine power, thanks to the engine beep switches as long as the Essential busses are powered, if no Essential busses, then the crew can physically move the ECL manually.