Audi A6, S6, RS6 & allroad quattro 1998–2004 Service Manual

This Bentley Publishers service manual covers 1998–2004 Audi A6, A6 Avant, allroad quattro, S6, and RS6 C5-platform models. It combines maintenance and repair procedures with engine-specific reference data and selected Audi wiring diagrams. The file has omissions in several body and interior-lighting sections.

Text Search, Wiring Detail and Page Count

Search and diagram detail: OCR text supports searches across many repair sections, but coverage is incomplete. The 1999 and 2000 maintenance schedules and some wiring-diagram text are not searchable. Seven numbered bookmarks provide coarse navigation. Small wiring labels require zooming, and some legends are faint.

One printable, English-language, 937-page PDF, including 16 blank pages, a repeated exterior-lighting page, and one closing supplementary page.

Engine Timing, Drivetrain Service and Electrical Fault Tracing

These are selected contents, rather than a complete contents list. Further topics include service-reminder resetting and tire-pressure monitoring system setup.

• Engine service: Timing-belt replacement, crankshaft pulley and rear main seal procedures, cylinder head cover replacement, and lubrication-system testing.

• Fuel and emissions: Fuel-pump electrical checks, delivery-volume and residual-pressure tests, oxygen-sensor replacement, and turbocharger cooling and secondary-air injection schematics.

• Clutch and drivetrain: Clutch hydraulic repairs, self-adjusting pressure-plate resetting, manual-transmission removal, gear-selector adjustment, and driveshaft alignment checks.

• Suspension and brakes: Strut and drive-axle service, brake pad replacement, ABS component procedures, hydraulic bleeding, and wheel-alignment specifications.

• Body and cabin: Door and window mechanisms, sunroof adjustment, interior trim removal, seat components, and restraint-system component replacement.

• Climate control: Blower, compressor, and heater-core replacement, supported by component layouts, airflow illustrations, and troubleshooting tables.

• Electrical diagnosis: Battery, starter, and charging-system troubleshooting, engine-specific wiring diagrams, component-location references, and VAG/SAE diagnostic trouble-code tables.

Written for independent service professionals and Audi owners with automotive mechanical skills, the manual also identifies work requiring specialized tools, equipment, or training.

Engine Timing and Motronic Applications

The step-by-step timing-belt procedure applies to the 2.7L and 2.8L V6 engines and identifies locking tools, including VAG 3391. The timing section warns that rotating the camshafts or crankshaft with the belt removed can damage valves.

Cooling-system procedures address draining, filling, bleeding, radiator replacement, and coolant-pump and thermostat service. Lubrication coverage includes oil-pressure and pressure-switch testing.

Bosch Motronic M5.9.2, ME 7.1, and ME 7.1.1 applications are distinguished by engine code. Sensor and actuator layouts identify components and connectors; the turbocharger section provides basic operating and cooling-system information.

Transmission Scope and Converter Installation

Manual-transmission coverage includes removal and installation, but excludes internal teardown and repair. Automatic-transmission coverage addresses external components, fluid-level checks, and adjustments; automatic transmission removal is outside the manual’s scope.

Torque-converter service assumes the transmission has already been removed. Its installation notes explain how incorrect converter seating can destroy the ATF pump shaft when the transmission is connected to the engine.

Suspension, Steering and Brake Variants

Product familiarization explains the allroad quattro four-level air suspension and RS6 Dynamic Ride Control. Service information includes allroad lifting-mode precautions and separate alignment data for FWD, V6 quattro, V8 quattro, and allroad configurations.

Brake coverage distinguishes FN-3, FNR-G60, allroad HP-2, and RS6 Brembo assemblies. Separate bleeding procedures address Bosch ABS/ASR 5.3 and ABS/ESP 5.7. Steering sections provide tie-rod and engine-specific power-steering pump replacement information.

Body, Restraints and Climate-Control Limits

Cabin sections include sunroof zero-position adjustment, window motors, seat-memory components, and climate-control housing layouts. Airbag and pyrotechnic seat-belt component procedures are included, but fault diagnosis and internal repair of those systems are excluded.

The body/front-lock-carrier, hood, door, and interior-lighting sections contain missing pages, including the detailed lock-carrier service-position instructions. Refrigerant evacuation and recharging procedures are also outside the manual’s scope.

Circuit References and Repair Planning

Selected wiring diagrams cover engine-management applications, central locking, xenon headlights, and seat electronics. Ground-location drawings and the VAG 1551/1552 operating overview flowchart complement CAN-bus explanations and voltage-drop testing.

Cross-referenced component locations, specifications, and tool requirements support repair planning before disassembly. They help distinguish the applicable engine or system version before selecting a test or replacement procedure.

Working on automotive systems involves heavy components and high pressures. Always ensure a safe working environment, use properly rated lifting equipment, and verify procedures against applicable factory specifications.

A Sample of Oil, Cooling and Chassis Specifications

Approximate oil capacities, including the filter, are 5.7 liters for AHA/ATQ engines and 8.5 liters for the BAS allroad quattro V8. The oil-change procedure specifies 30 Nm for the drain plug with a replacement gasket.

The cooling-system table lists 12.0 liters for the BCY RS6 biturbo engine, alongside filling and bleeding information.

Chassis maintenance specifies 40 Nm for the tie-rod end lock nut, with accompanying checks for joint play and dust-boot condition.