A method of assembling an electronic control unit comprises assembling a printed circuit board (PCB) substrate with a terminal carrier holding a plurality of terminal pins comprising a right angle bend into a housing using a rotational motion. The terminal carrier generally extends perpendicularly from the PCB substrate. A first end of each of the plurality of terminal pins is inserted into the PCB substrate and a second end of each of the plurality of terminal pins extends through the terminal carrier. The second ends of the plurality of terminal pins generally extend into one or more connector openings in one of four sides of the housing and the terminal carrier interlocks with the housing to hold the PCB substrate with the terminal carrier and the plurality of terminal pins in place.