The supplement VAS 6209/2 is required on the Audi RS4 to perform the pressure test on the DRC system. A pressure test is necessary to determine whether the DRC system requires filling. The application is described in the relevant workshop manual. Recommended accessories Filling device for DRC system, Audi RS6 VAS 6209, ASE 425 003 00 000 Filler for DRC system, Audi RS4 VAS 6209/1; ASE 425 010 00 000