This service manual covers Mercruiser D 2.8L D-Tronic and D 4.2L D-Tronic marine engines, designed for marine propulsion. These in-line diesel engines, available in Sterndrive (MCM) and Inboard (MIE) configurations, have been manufactured since 1997. They are engineered for reliability and performance in demanding marine environments, offering robust power and efficient operation for a wide range of vessels. This comprehensive service manual provides detailed information essential for the maintenance, repair, and troubleshooting of your Mercruiser marine engine. It includes extensive coverage of general information, maintenance procedures, fuel system, cooling system, intake/exhaust system, drive system, power steering system, starting system, charging system, glow plug system, and instrumentation. With step-by-step instructions and diagnostic capabilities, including EDI Diagnosis, this manual is an indispensable resource for owners, mechanics, and technicians to ensure the optimal performance and longevity of their marine propulsion system.