There are many sensors included as a part of the trans components- manual in your Audi 90 Quattro. The primary task of a sensor is to measure an element of the engine function and generate a warning signal if something is malfunctioning. These pieces could evaluate shaft speed, fluid temperature, or transmission speed.
The job of the transmission is to transfer the power of the engine throughout the drive train to the front and rear tires of the Audi 90 Quattro. When operating correctly, the transmission moves between gears and maintains driving stability. Without the assistance of sensors, complete failure could occur. StockWiseAuto.com has the parts you need when sensors go bad.