On the 2.0L TDI common rail Diesel engine/clean Diesel engine, fuel injection pulses could coincide with the natural frequency of injector line #2. This resonance creates additional stress on the fuel line. Small cracks could develop in the #2 injector line, resulting in a Diesel fuel leak. A fuel leak always increases the risk of a fire. Dealers will install an improved #2 fuel injector line and install vibration dampers on all of the injector lines to correct this concern. The Volkswagen/Audi recall number is 23J9/V5.