Audi A6 (C5) | 1997-2004 | Fuse Box Diagrams and Locations

The second-generation (Mk2) Audi A6, S6, and RS6 (chassis codes C5/4B), Audi’s luxurious and performance-oriented mid-size sedans and wagons, were produced from 1997 to 2004. This generation offered a combination of refined design, advanced technology, and high-performance variants, establishing itself as a cornerstone in Audi’s lineup.

In this article, you will find detailed fuse box diagrams for Audi A6, S6, and RS6 models produced between 1997 and 2004. These diagrams provide essential insights into the vehicle’s electrical systems, including the assignment of each fuse (fuse layout) and relay. This information is crucial for troubleshooting electrical issues, performing maintenance, or carrying out necessary repairs.

This guide is a practical resource for understanding the electrical system of the second-generation Audi A6, S6, and RS6, ensuring that owners have the knowledge needed to maintain the functionality, reliability, and performance of these premium and high-performance vehicles.

What’s Included

Instrument Panel Fuse Box

Fuse Box Location

The fuses are behind a cover on the driver’s side.

Location of the fuses in the passenger compartment: Audi A6 (1997-2004)

Fuse Box Diagram

Assignment of the fuses in the instrument panel

№	Amps	Function/component
1	5A	Heater element, left washer jet Heater element, right washer jet
2	10A	Hazard warning light switch
3	5A	Glove box light
4	5A	Number plate light
5		1997-1999: Dash panel insert, air conditioner, auxiliary heater, exterior mirrors, heated seats, rear window blind, navigation system, parking aid
5		2000-2002: Seat heating, bulb monitoring device, mirror switch, mirror adjustment motors, air conditioner, auxiliary heater, rear roller blind, control unit for: parking aid, navigation system, telephone/telematics, self-levelling suspension, electrical tyre pressure monitoring (alknad models), automatic gearbox (Tiptronic switch)
5	10A	2003-2004: Oil level/oil temperature sender Compressor regulating valve, air conditioning system High pressure sender Tiptronic switch Tyre pressure monitor control unit Bulb monitoring device Mobile phone operating electronics control unit Control and display unit for air conditioner/Climatronic Air quality sensor Navigation system with CD drive control unit Self-levelling suspension control unit Operating unit to control suspension height Telephone/telematics control unit Control unit for voice control Parking aid control unit Rear roller blind switch
6	5A	Central locking control unit
7	10A	ABS control unit Steering angle sender TCS/ESP button Cruise control system brake pedal switch (diesel direct injection system) Clutch pedal switch
8	5A	Telephone/telematics control unit Control unit for voice control
9	10A	Heated exterior mirror, driver’s side Heated exterior mirror, front passenger’s side
10	5A	Headlight range control, control unit
11		1997-1999: Cruise control system (CCS)
11	5A	2000-2004: Automatic anti-dazzle interior mirror
12	10A	Diagnosis connection
13	10A	Brake light switch Brake light bulbs
14		1997-2002: Interior lighting control unit, reading lamps, central locking control unit, vanity mirrors, seat adjustment memory
14	10A	2003-2004: Central locking control unit Memory operating unit, driver’s seat Memory operating unit, front passenger’s seat Luggage compartment release switch Interior monitor switch
15	10A	Control unit with display in dash panel insert Solar cell isolation relay Navigation system with CD drive control unit Mirror memory control unit Auxiliary heating radio controlled receiver
16	5A	Steering angle sender
17	10A	Tyre pressure monitor control unit Self-levelling suspension control unit Two-way radio switch Parking aid control unit
18	10A	Main beam bulb, right Main beam warning lamp
19	10A	Main beam bulb, left
20	15A	Dipped beam bulb, right Headlight range control motor, right
21	15A	Dipped beam bulb, left Headlight range control motor, left
22	5A	Side light bulb, right Tail light bulb, right
23	5A	Side light bulb, left Tail light bulb, left
24	25A	Automatic intermittent wash/wipe relay Intermittent wiper control
25	30 A	Control and display unit for air conditioner/Climatronic Solar cell isolation relay Fresh air blower Magnetic coupling relay Auxiliary heater relay
26	30A	Control and display unit for air conditioner/Climatronic Heated rear window switch
27	15A	Heated steering wheel Rear window wiper motor
28	20A	Fuel pump (pre-supply pump) Fuel pump control unit Fuel pump relay
29	20A/30A	Ignition coil with output stage (engine code BAS) Motronic control unit (engine code BAS) Output stage Ignition coil with output stage Motronic control unit Camshaft timing adjustment valves
30	20A	Sliding sunroof adjustment control unit
31		1997-1999: Automatic gearbox, reversing lights, cruise control system, automatic anti-dazzle interior mirror
31		2000-2002: Automatic gearbox, reversing lights, diagnostic socket, navigation system, rpm boost, exhaust gas recirculation frequency valve, hazard warning light switch illumination
31	15A	2003-2004: Starter inhibitor and reversing light relay Hazard warning light switch Reversing light switch Diagnosis connection Multi-function switch Ignition cut-off delay relay Automatic gearbox control unit
32	20 A	Injectors Cruise control system switch
33	15A	Cigarette lighter Cigarette lighter, rear
34	15A	Secondary air pump relay Solenoid valves Secondary air inlet valve Turbocharger divert air valve Air mass meter Heater for lambda probes Intake manifold change-over valve Injectors Cruise control system
35	30A	Trailer socket
36	15A	Front and rear fog light switch
37	20A	Radio Amplifier with bass loudspeaker Aerial selection control unit Operating electronics control unit, navigation Navigation/TV tuner Navigation interface Chip card reader unit
38		1997-1999: Luggage compartment light, central locking system
38	20A	2000-2004: Central locking control unit
39	15A	Hazard warning light switch
40	25A	Dual tone horn relay
41	25A	Relay for ABS solenoid valves (allroad models)
42	25A	ABS control unit
43	5A	Radio Operating electronics control unit, navigation
44	30A	Auxiliary heater relay Solar cells isolation relay 2 Heated driver’s seat regulator Heated front passenger’s seat regulator Heated rear left seat switch with regulator Heated rear right seat switch with regulator

Relay Panels

13-point relay carrier

It is behind driver’s storage compartment.

№	Description
1	Dual tone horn relay (telematics – USA)
2	Alternator cut-in relay Alarm system control unit (taxi) Siren relay (police vehicles) Alarm system relay, light change-over (special vehicles)
3	Solar cell isolation relay Alarm system control unit (taxi) Siren relay (police vehicles) Alarm system relay 2, intermittent main beam (special vehicles)
4	Starter inhibitor relay Starter inhibitor and reversing light relay
5	Magnetic coupling relay Auxiliary heater relay
6	Fog light relay Fuel pump relay (TDI engines)
7	Multi-function steering wheel control unit
8	Multi-function steering wheel control unit
9	Bulb monitoring device
10	Bulb monitoring device
11	Exterior mirror fold system control unit
12	Exterior mirror fold system control unit
13	Servotronic control unit
14	Taximeter fuse Fuse E (police vehicles) Hydraulic pump relay fuse (allroad models)
15	–
16	Alarm system fuse (taxi) Fuse B (police vehicles)
17	Taximeter and alarm system fuse (taxi) Fuse C (police vehicles) Intercom system fuse (special vehicles) Fog light fuse (daytime driving lights – Canada)

Micro-central electrics

It is behind driver’s storage compartment.

№	Description
1	Dual tone horn relay
2	X contact relief relay
3	Low range gearing hydraulic pump relay (allroad models)
4	Fuel pump relay (petrol engines) Relay for glow plugs (diesel engines)
5	Automatic intermittent wash/wipe relay
6	Automatic intermittent wash/wipe relay
A	1997-1999: Self-levelling suspension fuse 2000-2004: Steering column adjustment fuse
B	Rear roller blind fuse
C	For special vehicles

8-point relay carrier

It is behind driver’s storage compartment, behind micro-central electrics

Left-hand drive vehicles

8-point relay carrier (LHD): Audi A6 (1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004)

№	Description
1	Relay for solenoid valves – ABS with ESP
2	Radiator fan 2nd speed relay
3	Radiator fan relay Continued coolant circulation relay
4	Radiator fan run-on relay
5	–
6	Self-levelling suspension compressor relay (allroad models)
7	Return flow pump relay – ABS with ESP
8	2000-2002: Auxiliary heater control unit (small cooling circuit)
8	2003-2004: Coolant shut-off valve relay
14	Seat adjustment thermo-fuse, driver’s side (allroad models)
15	Fuse for 12V socket
16	Front electric window thermo-fuse
17	Rear electric window thermo-fuse
18	ABS control unit fuse
19	Radiator fan fuse
20	Radiator fan control unit fuse
21	Seat adjustment thermo-fuse, driver’s side Radiator fan fuse (allroad models)
22	Self-levelling suspension fuse
23	Self-levelling suspension fuse
24	Seat adjustment thermo-fuse, front passenger’s side

Right-hand drive vehicles

№	Description
2	Self-levelling suspension compressor relay (allroad models)
3	Radiator fan run-on relay
4	Relay for solenoid valves – ABS with ESP
5	Radiator fan relay
6	Return flow pump relay – ABS with ESP
7	Radiator fan 2nd speed relay
8	–
9	–
10	–
11	Self-levelling suspension fuse Seat adjustment thermo-fuse, front passenger’s side (RS6 models)
12	Seat adjustment thermo-fuse, front passenger’s side Radiator fan fuse (RS6 models)
13	Front electric window thermo-fuse
14	Rear electric window thermo-fuse
15	Seat adjustment thermo-fuse, driver’s side
16	Radiator fan fuse
17	Radiator fan control unit fuse Fuse for 12V socket (RS6 models)
18	ABS control unit fuse
19	Fuse for 12V socket

Relay carrier

It is on the driver’s side, behind dash panel at central carrier.

№	Description
1	Low heat output relay Brake servo relay
2	Auxiliary heater relay Solar cells isolation relay 2 (LHD)
3	High heat output relay
A	–
B	1997-1999: Fuse for fuel cooling
C	Additional heater fuse 2 Hydraulic pump relay fuse (brake servo) Fuel pump fuse (RS6 models LHD)
D	Additional heater fuse Fuel pump fuse (RS6 models RHD)

3-point relay carrier

In the engine compartment (electronics box).

Version 1

3-point relay carrier (ver.1): Audi A6 (1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004)

№	Decription
1	Additional heater 1 relay (TDI)
2	Secondary air pump relay
3	Diesel direct injection system relay
5	Engine control unit fuse
7	Fuse for glow plugs (V6 TDI), secondary air pump fuse
8	Additional heater 2 fuse (TDI), fuse stage 2 (V6 TDI)
9	Fuse 2 for glow plugs (V6 TDI), fuse for glow plugs (4-cylinder)

Version 2

3-point relay carrier (ver.2): Audi A6 (1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004)

№	Description
1	Secondary air pump relay (RS6 models) Auxiliary water pump relay (2000)
1a	Radiator fan relay (allroad models)
1b	Continued coolant circulation relay (allroad models) Additional coolant pump relay (2003)
2	Secondary air pump relay
3	Motronic current supply relay (petrol engines) Diesel direct injection system relay (diesel engines) Ignition cut-off delay relay (automatic gearbox 01J)
4	Fuel cooling pump relay Continued coolant circulation relay (RS6 models)
4a	–
5	Engine control unit fuse Engine electronics fuse (allroad models)
6	Not used (left-hand drive vehicles) Fuse 2 for glow plugs (V6 TDI, V8 TDI) Fuse for glow plugs (4-cylinder Radiator fan fuse (allroad models)
7	Fuse for glow plugs (V6 TDI, V8 TDI) Secondary air pump fuse (petrol engines) Auxiliary heater fuse (right-hand drive vehicles) up to model year 2000 Not used (right-hand drive vehicles)
8	Auxiliary heater fuse (left-hand drive vehicles) up to model year 2000 Not used (left-hand drive vehicles)
9	Fuse 2 for glow plugs (V6 TDI, V8 TDI) Fuse for glow plugs (4-cylinder) Radiator fan fuse (allroad models) Coolant pump fuse (RS6 models) Not used (right-hand drive vehicles)
10	Fuse for fuel cooling Fuse -1- (15) (automatic gearbox 01J) Radiator fan control unit fuse (allroad models) Not used (right-hand drive vehicles)

Fuses not in relay carrier

Fuse for auxiliary heater
Fuse for fuel cooling
Fuse -1- (15) (automatic gearbox 01J)
Radiator fan control unit fuse (allroad models)

Additional fuses in plenum chamber

RS6:

The fuses are located below coolant expansion tank.

Additional fuses in plenum chamber (RS6): Audi A6 (1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004)

№	Description
1	Fuse -2- (30)
2	Fuse -1- (30)
3	Auxiliary heater fuse Battery screw connection (RS6)