I have an electrical problem with power to my ecu plug for my mk3 mondeo?

I went to a garage so they could scan my car because of an engine management light. There was no power to the plug. I checked the fuses and there is a 3amp fuse for the pcm(engine management control unit - F33) instead of a 7.5 amp fuse also there was another fuse missing for the engine management F41. Is it possible the pcm has been fried because of someone installing the wrong fuse. Strangely the car runs fine accept a bit of rev hunting when idling sometimes.