ASR and limp mode cause
It quite possibly is a bad wiring harness on th eelectronic throttle actuator or a bad main wiring harness. The insulation disintegtates on the individual wires inside the plastic bundle cover. So long as nothing shifts OK. Any movemetn and wires begin to touch and short --usually intermittenly at first.
Have them call in regional tech support. They seem to be swapping out good parts in a very expensive manner. Faulty wiring harnesses will give flakey component test results--often indicating 'bad', when the real problem is the wiring harness. When replacing the component does not cure the problem demand the old part be reinstalled since it obviously was not the cause in the first place.