2020 Audi A3 Sedan Service and Repair Manual

This 2020 Audi A3 Sedan Service and Repair Manual Covers

Engine & Drivetrain

• 1.0L TFSI petrol engine service and repair (market dependent)
• 1.5L TFSI petrol engine servicing
• 2.0L TFSI petrol engine repair procedures
• 1.6L TDI diesel engine servicing (where available)
• 2.0L TDI diesel engine repair procedures
• 1.4L TFSI e-tron plug-in hybrid diagnostics and repair (where equipped)
• 1.5L TGI CNG engine servicing (market dependent)
• Fuel injection and turbocharger diagnostics
• Engine cooling system repairs
• Exhaust and emissions control system servicing
• 6-speed manual transmission servicing
• 7-speed S tronic transmission diagnostics and repair
• quattro all-wheel drive system servicing (where equipped)
• Driveshaft, differential, and CV joint repairs

Braking Systems

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

Chassis & Suspension

• Front MacPherson strut suspension repairs
• Rear multi-link suspension servicing (quattro and higher-spec models)
• Rear torsion beam suspension servicing (selected front-wheel-drive models)
• Dynamic suspension diagnostics (where equipped)
• Progressive steering diagnostics (where equipped)
• Wheel alignment specifications
• Wheel bearing replacement procedures

Electrical & Wiring

• Complete factory wiring diagrams
• Battery management system diagnostics
• CAN Bus and LIN Bus communication diagnostics
• Gateway control module diagnostics
• Body Control Module (BCM) diagnostics
• Audi Virtual Cockpit diagnostics (where equipped)
• Audi MMI Navigation Plus diagnostics
• Instrument cluster diagnostics
• Bluetooth, USB, and smartphone interface diagnostics
• Central locking and lighting system repairs

Air Conditioning & HVAC

• Automatic climate control diagnostics
• Air conditioning compressor servicing
• Refrigerant recovery and recharge procedures
• HVAC control module diagnostics
• Heating and ventilation system repairs
• Cabin air quality sensor diagnostics (where equipped)

Body & Interior

• Interior trim removal and installation
• Dashboard servicing procedures
• Door control module diagnostics
• Power window and central locking repairs
• LED and Matrix LED headlamp diagnostics (where equipped)
• Airbag and occupant restraint system diagnostics
• Seat adjustment system repairs (where equipped)
• Body panel alignment and repair information

Advanced Driver Assistance Systems (ADAS)

• Audi Pre Sense Front diagnostics (where equipped)
• Adaptive Cruise Control diagnostics (where equipped)
• Lane Departure Warning system diagnostics (where equipped)
• Audi Side Assist (Blind Spot Monitoring) diagnostics (where equipped)
• Rear Cross Traffic Assist diagnostics (where equipped)
• Parking System Plus diagnostics
• Front camera calibration procedures
• Radar sensor calibration procedures
• Parking sensor diagnostics

Diagnostics & Troubleshooting

• ODIS factory diagnostic procedures
• Diagnostic Trouble Code (DTC) lookup procedures
• Guided fault-finding routines
• ECU coding and adaptation procedures
• Software updates and module programming
• 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 2020 Audi A3 Sedan.

Engine Codes

• P0299 – Turbocharger Underboost Condition
• P0171 – System Too Lean (Bank 1)
• P0300 – Random/Multiple Cylinder Misfire Detected
• P0420 – Catalyst System Efficiency Below Threshold
• P20EE – SCR NOx Catalyst Efficiency Below Threshold (diesel models)

Transmission Codes

• P0726 – Engine Speed Input Circuit Range/Performance
• P1735 – S tronic Clutch Adaptation Fault
• P17BF – Hydraulic Pump Protection Fault

ABS & Chassis Codes

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

Network Communication Codes

• U0100 – Lost Communication with ECM/PCM
• U1113 – Function Restriction Due to Missing Message
• U1123 – Data Bus Communication Fault

Body Control & ADAS Codes

• B2000 – Control Module Internal Malfunction
• B126A – Front Camera Calibration Required
• C1103 – Radar Sensor Misalignment
• C1116 – Lane Assist Camera Fault

The manual also includes hundreds of manufacturer-specific fault codes, wiring diagrams, guided diagnostic routines, calibration procedures, software configuration information, and repair instructions.

Who Is This Manual For?

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

If you are servicing, maintaining, diagnosing, or repairing a 2020 Audi A3 Sedan, this factory workshop manual provides the detailed repair procedures, wiring diagrams, diagnostic information, and calibration procedures required to maintain the vehicle to Audi factory standards.