Instruction book AUDI A4
 Audi A4   Controls   Instruments and warning/indicator lamps  Warning and indicator lamps
If the indicator lamp flashes, the turn signals are on in towing mode.
If a turn signal bulb on the trailer or Audi A4 fails in towing mode, the indicator lamp does not flash twice as fast to indicate the bulb failure.

All images, logos and text are property of © Audi. This site has no relationship with the company Volkswagen - Audi Spain nor any of its affiliates worldwide. For more information. To contact the author of this website click here.