If you checked for ground by using the tone for continuity check on a multimeter, I'm thinking your "ground G101" may be the load side of the relay finding a path to ground either through one of the sub relays or through the injectors/coils. There should be a measurable resistance if that is the case, but it will still show continuity to ground.
See if you have Continuity to one of the fuses shown on that circuit from terminal labeled G101.