A circuit board assembly for a control unit of a motor vehicle has a multi-layer circuit board and a plug connector with a housing faceplate. The circuit board, which includes conductor paths for conducting signals, has a first section, a second section, and a flexible third section with a lower stiffness between the first and second sections. The first section encloses an angle φ with the second section. The plug connector has a multiplicity of connection elements, each with an attachment part and a contact pin. The housing faceplate has first and second side panels each enclosing an angle β with the first panel central plane and an angle γ with the second panel central plane. A first detent element prevents a change in the angle φ in a first direction of rotation. A second detent element prevents a change in the angle φ in a second direction of rotation.