Ive got 1.4 16v FXJA fiesta with intermittent Eac fault, when fault occurs it triggers p0642, Eac warning comes on , dash flashes and car struggles to rev and cuts out . Restart and fault goes. I've checked 5v reference voltage at app, ecu and throttle body and ok when fault occurs. Sent throttle body to Actronics and they can't fault. Ive retested reference voltages and ok.
Ids fault code description for P0642 voltage supply to vcc1 short to ground.

Checked earths under battery and ok.
Spoke to Ford technical and they said check wiring, but could not tell me what the acronym vcc1 related to, I presume its the throttle body as if I disconnect app vcc2 fault registers.
Any advice would be appreciated.
Thanks
Joe