This workshop service repair manual covers the Mitsubishi FB16KT, FB18KT, and FB20KT Controller Forklift Trucks, part of the EFB4A and EFB5A model series. These electric counterbalance forklift trucks are engineered for reliability and efficiency in material handling operations, featuring robust electric drive systems and advanced controller technology. The manual provides in-depth information to ensure these machines operate at peak performance, focusing on their sophisticated control systems, electric motors, and associated circuitry. The purpose of this comprehensive manual is to provide detailed guidance for the service, repair, and maintenance of the specified Mitsubishi forklift models. It covers essential areas including controller systems, motor control, electrical schematics, and systematic troubleshooting procedures. With step-by-step repair instructions, component testing methods, and clear circuit diagrams, this resource is invaluable for forklift technicians, service departments, and do-it-yourselfers aiming to maintain and optimize their equipment, ultimately leading to cost savings and extended operational life.