An engine start using an electric motor during a vehicle travel is performed by increasing an output torque of the electric motor in a slip state where a second frictional engagement element 3 connecting the electric motor 1 and a driving wheel slips. A switch circuit is disposed in each of a plurality of nodes which are cascade connected with each other in a plurality of stages. One variation generally comprises a handle portion with an elongate outer jacket extending from the handle portion. When filtering instances are inserted to or removed from a filter stack, associated protocol stacks may remain capable of transferring data.