The 1993 Audi 90, built on the Type 89 platform, represents Audi's commitment to German engineering and refined driving dynamics. As a compact executive sedan, it offered a blend of understated luxury and performance, notably featuring advanced aerodynamic styling and the sophisticated quattro all-wheel-drive system. Available with smooth 5-cylinder (2.6L ABC/ABD) or V6 (2.8L AAH) engines, and either a 5-speed manual or 4-speed automatic transmission, the Audi 90 provided a compelling option in its segment, competing with established European rivals. Its design emphasized quality and a comfortable yet engaging driving experience, embodying Audi's 'Vorsprung durch Technik' philosophy.

This comprehensive service manual provides detailed factory-level diagnostic and repair procedures for the 1993 Audi 90. It covers essential maintenance, intermediate repairs, and advanced diagnostics across all major vehicle systems, including engine mechanicals, fuel, ignition, transmissions (manual and automatic), drivetrain (including quattro), suspension, steering, brakes, and electrical systems. The manual also includes troubleshooting guides, wiring diagrams, torque specifications, and information on special tools. Its purpose is to assist owners, mechanics, and technicians in maintaining, troubleshooting, and repairing the vehicle to factory standards, ensuring its longevity and optimal performance.