This workshop service manual covers Volvo Penta 280-DP, 285-DP, and 290-DP sterndrive marine engines, part of the DP Series. These inboard marine engines, with displacements ranging from 2.6L to 2.7L, are engineered for reliable performance in demanding marine environments. The manual encompasses a wide array of applicable engine models, including AQ280, AQ285, AQ290, and their various sub-models, ensuring comprehensive support for these robust sterndrive units. This document provides essential information for the repair, service, and maintenance of your Volvo Penta sterndrive. It features step-by-step instructions, detailed illustrations, diagrams, and pictures to guide you through complex procedures. The manual includes technical data, specifications for special tools, tightening torques, information on trim systems, wiring diagrams, sterndrive extensions, pressure and vacuum testing, welding and painting systems, and relevant service bulletins. This resource is designed to assist owners, mechanics, and technicians in maintaining the optimal performance and longevity of their marine propulsion systems.