This manual provides comprehensive service and repair information for the 1990 Audi 100 (C4-4A), encompassing all sedan and Avant variants. Representing sophisticated German engineering, the Audi 100 of this era was positioned as a premium mid-size executive vehicle, known for its refined interior, robust build quality, and the availability of the renowned Quattro all-wheel-drive system. This generation, produced from 1990 to 1994, featured sleeker styling and improved aerodynamics, offering a compelling alternative to established European luxury sedans. The vehicle’s engineering philosophy emphasized driver comfort and performance, with available five-cylinder engines and advanced fuel injection systems of the time.

This Service and Repair Manual is designed to assist professional technicians and experienced DIY enthusiasts in maintaining and repairing the 1990 Audi 100. It covers a vast range of systems, including engine mechanicals, fuel injection, ignition, cooling, lubrication, transmission (manual and automatic), driveline, suspension, steering, braking systems (including ABS), and electrical systems. Detailed procedures for routine maintenance, complex repairs, and systematic troubleshooting are provided, along with essential technical specifications, torque values, and diagnostic charts. With over 1000 pages of dealership-level technical data, this manual is an indispensable resource for ensuring the optimal performance and longevity of your Audi 100.