2005 Audi A6 Service and Repair Manual

This 2005 Audi A6 Service and Repair Manual Covers

Engine & Drivetrain

• 2.0L TFSI turbocharged petrol engine service and repair (introduced in selected markets)
• 2.4L V6 petrol engine servicing
• 3.2L FSI V6 petrol engine servicing
• 4.2L V8 petrol engine servicing (selected models)
• 2.0L TDI turbo diesel engine servicing
• 2.7L TDI V6 diesel engine servicing
• 3.0L TDI V6 turbo diesel engine servicing
• Fuel injection and turbocharger diagnostics
• Engine cooling system servicing
• Engine lubrication system repairs
• Exhaust and emissions control system diagnostics
• 6-speed manual transmission servicing
• Multitronic CVT servicing (front-wheel-drive models)
• 6-speed Tiptronic automatic transmission diagnostics and repair
• quattro permanent all-wheel drive system servicing
• Torsen centre differential, propeller shaft, rear differential, and CV joint repairs

Braking Systems

• Hydraulic brake system servicing
• Anti-lock Braking System (ABS) diagnostics
• Electronic Stability Program (ESP) diagnostics
• Electronic Parking Brake (EPB) servicing
• Brake Assist system diagnostics
• Brake pad, brake disc, and caliper replacement procedures
• Brake hydraulic system bleeding

Chassis & Suspension

• Front four-link suspension repairs
• Rear trapezoidal-link suspension servicing
• Standard and Sport suspension servicing
• Adaptive Air Suspension diagnostics (where equipped)
• Wheel alignment specifications
• Wheel bearing replacement procedures
• Steering system diagnostics and repairs
• Suspension component inspection and troubleshooting

Electrical & Wiring

• Complete factory wiring diagrams
• Battery, charging, and starting system diagnostics
• CAN Bus, LIN Bus, and MOST communication diagnostics
• Gateway control module diagnostics
• Body Control Module (BCM) diagnostics
• Audi MMI 2G High diagnostics
• Instrument cluster diagnostics
• Bluetooth® phone preparation diagnostics (where equipped)
• CD changer and multimedia system diagnostics
• Bi-Xenon headlamp diagnostics (where equipped)

Air Conditioning & HVAC

• Dual-zone and four-zone automatic climate control diagnostics (model dependent)
• Air conditioning compressor servicing
• Refrigerant recovery and recharge procedures
• HVAC control module diagnostics
• Air quality sensor testing
• Heating and ventilation system repairs

Body & Interior

• Interior trim removal and installation
• Dashboard servicing procedures
• Sedan and Avant body repair procedures
• Door control module diagnostics
• Power window and central locking repairs
• Exterior lighting system servicing
• Airbag and occupant restraint system diagnostics
• Electrically adjustable, heated, and memory seat repairs (where equipped)
• Sunroof diagnostics and servicing (where equipped)
• Body panel alignment and repair information

Driver Assistance Systems

Available equipment varies by market and trim level.

• Adaptive Cruise Control diagnostics (where equipped)
• Audi Side Assist (Blind Spot Monitoring) diagnostics (where equipped)
• Parking System Plus diagnostics
• Front and rear parking sensor diagnostics
• Rear-view camera diagnostics (where equipped)
• Adaptive headlight system diagnostics (where equipped)
• Steering angle sensor calibration

Diagnostics & Troubleshooting

• VAS factory diagnostic procedures
• Guided fault-finding routines
• Diagnostic Trouble Code (DTC) lookup procedures
• ECU coding and adaptation procedures
• Component protection diagnostics
• Sensor and actuator testing
• Step-by-step troubleshooting workflows

Common Error Codes Covered

This manual includes diagnostic procedures for common Audi fault codes applicable to the 2005 Audi A6.

Engine Codes

• P0087 – Fuel Rail/System Pressure Too Low
• P0171 – System Too Lean (Bank 1)
• P0300 – Random/Multiple Cylinder Misfire Detected
• P0401 – Exhaust Gas Recirculation Flow Insufficient Detected (diesel models)
• P0299 – Turbocharger Underboost Condition (turbocharged engines)

Transmission Codes

• P0726 – Engine Speed Input Circuit Range/Performance
• P0730 – Incorrect Gear Ratio
• P0746 – Pressure Control Solenoid Performance
• P179E – Multitronic Transmission Control Fault (CVT models)

ABS & Chassis Codes

• C0031 – Left Front Wheel Speed Sensor Fault
• C1146 – Steering Angle Sensor Calibration Fault
• C10AC – Electronic Parking Brake Malfunction

Network Communication Codes

• U0100 – Lost Communication with Engine Control Module
• U0155 – Lost Communication with Instrument Cluster

Body Control Codes

• B2000 – Control Module Internal Malfunction
• B1263 – Rain and Light Sensor Fault
• B11CF – Interior Lighting Circuit Fault

The manual also includes hundreds of manufacturer-specific diagnostic trouble codes, factory wiring diagrams, ECU coding procedures, guided diagnostics, component testing specifications, and repair instructions.

Who Is This Manual For?

• Professional automotive workshops
• Audi dealership technicians
• Independent repair garages
• Mobile mechanics
• Automotive engineering students
• DIY enthusiasts

If you are servicing, maintaining, diagnosing, or repairing a 2005 Audi A6, this factory workshop manual provides the detailed repair procedures, wiring diagrams, technical specifications, diagnostic information, and repair procedures required to maintain the vehicle to Audi factory standards.