An implantable control module for an electrical stimulation system includes an electronic subassembly disposed in a sealed conductive housing. A plurality of feedthrough pins extend through the sealed housing and couple connector contact of an external connector to the electronic subassembly. Each of the plurality of conductive pathways electrically couples a different one of the plurality of feedthrough pins to the electronic subassembly. A ground line electrically couples the electronic subassembly to the housing. A capacitive flex circuit is disposed in the housing and couples to each of the feed through pins. For each of the plurality of feedthrough pins the capacitive flex circuit includes a first conductive path electrically coupling the feedthrough pin to a corresponding conductive pathway of the plurality of conductive pathways, and a second conductive path electrically coupling the feedthrough pin to the ground pin.