Audi A4: Sound System

 Finding Leaks via Vacuum Test using A/C Service Station or Nitrogen Pressure Testing

Vehicles with a High Voltage System (Hybrid Vehicles) Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system. Refer to → Chapter "Warnings when Working on Vehicles with High Voltage System" and → Electrical Equipment; 

 Vehicles with Restrictor, Reservoir and A/C Compressor Regulator Valve -N280- (Externally Regulated A/C Compressor), Checking Pressures

Specified Values for the Refrigerant Circuit Pressures   Note Connect the Air Conditioning (A/C) service station. Refer to → Chapter "A/C Service Station, Connecting". Observe the test requirements. Refer to → Chapter "Pressures, Checking". - With the ignition switched