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Vacuum Diagrams: Introduction

This article contains underhood views or schematics of vacuum hose routing. Use these vacuum diagrams during visual inspection in BASIC DIAGNOSTIC PROCEDURES article. This will assist in identifying improperly routed vacuum hoses which cause driveability and/or computer indicated malfunctions.

NOTE: Vacuum diagram information for A8, RS6 and S8 equipped with 4.2L engine is not available.

Fig 1: Vacuum Diagram (A4 - 1.8L Turbo)

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Courtesy of AUDI OF AMERICA, INC.

Fig 2: Evaporative Emissions System Vacuum Diagram (A4 - 1.8L Turbo)

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Courtesy of AUDI OF AMERICA, INC.

Fig 3: Secondary Air Injection System Vacuum Diagram (A4 - 1.8L Turbo)

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Courtesy of AUDI OF AMERICA, INC.

Fig 4: Vacuum Diagram (A4 & A6 - 3.0L)

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Courtesy of AUDI OF AMERICA, INC.

Fig 5: Boost Pressure Control Vacuum Diagram (A6, Allroad & S4 - 2.7L Turbo)

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Courtesy of AUDI OF AMERICA, INC.

Fig 6: Recirculating Air Control Vacuum Diagram (A6, Allroad & S4 - 2.7L Turbo)

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Courtesy of AUDI OF AMERICA, INC.

Fig 7: Crankcase Ventilation Vacuum Diagram (A6, Allroad & S4 - 2.7L Turbo)

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Courtesy of AUDI OF AMERICA, INC.

Fig 8: Evaporative Emissions System Vacuum Diagram (A6, Allroad& S4 - 2.7L Turbo - 1 Of 2)

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Courtesy of AUDI OF AMERICA, INC.

Fig 9: Evaporative Emissions System Vacuum Diagram (A6, Allroad & S4 - 2.7L Turbo - 2 Of 2)

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Courtesy of AUDI OF AMERICA, INC.

Fig 10: Suction Jet Pump Vacuum Diagram (A6, Allroad & S4 - 2.7L Turbo - A/T)

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Courtesy of AUDI OF AMERICA, INC.

Fig 11: Evaporative Emissions System Vacuum Diagram (A6 - 4.2L)

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Courtesy of AUDI OF AMERICA, INC.

Fig 12: Vacuum Diagram (TT - Engine Code AMU)

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Courtesy of AUDI OF AMERICA, INC.

Fig 13: Vacuum Diagram (TT - Engine Code ATC)

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Courtesy of AUDI OF AMERICA, INC.

Fig 14: Vacuum Diagram (TT - Engine Code AWP)

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Courtesy of AUDI OF AMERICA, INC.

Fig 15: Evaporative Emissions System Vacuum Diagram (TT)

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Courtesy of AUDI OF AMERICA, INC.