Audi A4 (B7) | 2004-2008 | Fuse Box Diagrams and Locations

The third-generation (Mk3) Audi A4 and S4 (chassis codes B7/8E/8H), Audi’s luxury sedan and high-performance variant, was produced from 2004 to 2008. Known for its sleek design, enhanced technology, and dynamic driving experience, this generation of the A4 and S4 further established Audi as a leader in the luxury sedan market.

In this article, you will find detailed fuse box diagrams for Audi A4 and S4 models produced in 2004, 2005, 2006, 2007 and 2008. These diagrams provide valuable insights into the vehicle’s electrical systems, helping owners and technicians understand the assignment of each fuse (fuse layout). This information is vital for diagnosing electrical issues, performing maintenance, or completing necessary repairs.

This guide serves as a comprehensive resource for understanding the electrical system of the third-generation Audi A4 and S4, ensuring that owners have the knowledge and tools needed to maintain the reliability, functionality, and performance of these premium sedans.

What’s Included

Component Location

Main fuse
Connector station – Right A-pillar
Connector station – RF seat wiring
Relay panel (9-position) at Vehicle Electrical System Control Module
Relay panel (4-position) with threaded connection
Connector station – LF seat wiring
Fuse panel
Connector station – Left A-pillar
Connector station with threaded connection
Relay panel (4-position)

Instrument Panel Fuse Box

Fuse Box Location

The fuses are behind a cover on the driver’s side. Carefully pry the face cover off the instrument panel using the ignition key or a screwdriver.

Location of the fuses in the passenger compartment: Audi A4 (B7; 2004-2008)

Fuse Box Diagram

Assignment of the fuses in the instrument panel

№	Amps	Function/Component
1	10A	Climatronic Control Module
2	5A	Left Footwell Light Right Footwell Light
3	5A	Left Washer Nozzle Heater Right Washer Nozzle Heater Left Rear Footwell Light Right Rear Footwell Light
4	5A	Coolant Fan Control (FC) Control Module Coolant Fan Control (FC) Control Module 2
5	10A	Rear Window Shade Switch Function Selector Switch II Tiptronic Switch Oil Level Thermal Sensor Rear Window Shade Control Module Navigation System with CD Drive Control Module Parking Aid Control Module
6	5A	High Pressure Sensor Sensor for air quality
7	10A	Anti-Slip Control Switch Clutch Pedal Switch Brake Pedal Switch ABS Control Module
8	5A	Telephone Transceiver Telephone Amplifier
9	15A	Brake Booster Relay
10	5A	Headlamp Adjuster Headlamp Range Control Module Headlamp Range/Comering Lamp Control Module Left Headlamp Beam Adjusting Motor Right Headlamp Beam Adjusting Motor Right Dynamic Cornering Light Motor
11	5A	Airbag Control Module Warning Lamp for airbag off, passenger side
12	10A	16 pin connector, black, diagnostic connector
13	10A	Steering Column Electronic Systems Control Module
14	10A	Brake Light Switch
15	10A	Instrument Cluster Control Module Navigation System with CD Drive Control Module
16	5A	Garage Door Opener Control Head Garage Door Opener Control Module
17	10A	Rain/Light Recognition Sensor Parking Aid Control Module Tire Pressure Monitoring Control Module
18	5A	Left Dynamic Cornering Light Motor
19	10A	Left Lront Fog Lamp Right Front Fog Lamp
20	–	Not used
21	–	Not used
22	15A	Drivers Door Control Module Front Passenger’s Door Control Module
23	15A	Left Rear Door Control Module Right Rear Door Control Module
24	20A	Comfort System Central Control Module
25	30A	Fresh Air Blower Control Module
26	30A	Rear Window Defogger Relay
27	30A	Towing Recognition Control Module
28	20A	Transfer Fuel Pump (FP) Fuel Pump (FP) Control Module
29	–	Not used
30	20A	Power Sunroof Control Module
31	15A	Back-Up Light Switch Mass Air Flow (MAF) Sensor Light Recognition Sensor Starting Interlock Relay Transmission Control Module (ICM)
32	15A	Trailer Socket
33	15A/20A	Cigarette lighter
34	20A/30A	12V Socket
35	20A/30A	Socket
36	30A	Vehicle Electrical System Control Module Rear Window Wiper Motor
37	30A	Vehicle Electrical System Control Module Headlamp Washer Pump
38	15A	Radar Interior Monitoring Control Module 1 Alarm Horn Comfort System Central Control Module 8 pin Connector, black, radio connector III
39	20A	Radio Amplifier
40	25A	High Tone Horn Low Tone Horn Horn Relay
41	30A	Auxiliary Heater Control Module Auxiliary Heater Radio Receiver
42	25A	ABS Control Module
43	15A	Engine Timing Mass Air Flow (MAF) Sensor EGR Potentiometer SIMOS Control Module Power Supply Relay Engine Control Module (ECM) Engine Component Power Supply Relay EGR Vacuum Regulator Solenoid Valve
44	30A	Climatronic Control Module

Connector station – Right A-pillar

№	Amps	Circuit Protected
E	30A	Power Seat (with manual seats with power lumbar)
E	10A	Power Seat (with power seats)

Relay Panels

The relay panels are located behind instrument panel, driver’s side.

Relay panel (4-position) with threaded connection

Relay panel (4-position): Audi A4 (B7; 2004, 2005, 2006, 2007, 2008)

№	Amp Rating	Circuit Protected
F	10A/40A/60A	Fuse (Driver Fan training vehicle) (Not for Engine code BBK, BHF) Coolant Fan Fuse (Engine code BBK, BHF, BNS, BKN)
G	30A/40A/60A	Radiator After run Fuse (Engine code BBK, BHF, BNS, BKN) Coolant Fan Fuse (Not for Engine code BKN, BBK, BHF)
H	40A	ABS Control Module Fuse 1
3		NG Engine Throttle Relay 1 (not applicable to USA/CDN models)
4		NG Engine Throttle Relay 2 (not applicable to USA/CDN models)
4		Alarm – On/Hands-free Control Module (not applicable to USA/CDN models)

Relay panel (9-position)

№	Amps	Circuit Protected
A	10A	Rear Shade Circuit Breaker (Right)
B	10A	Rear Shade Circuit Breaker (Left)
D	30A	Power Windows Fuse 2
E	10A	Driver’s Power Seat Adjustment Circuit Breaker 2
E	10A	Driver’s Power Seat Adjustment Circuit Breaker 2 (Lumbar Support Adjustment)
F	30A	Power Windows Fuse
G	30A	Trailer Circuit Breaker
1		Fuel Pump (FP) Relay
2		Servotronic Control Module
3		Starter Relay 2 (For engine code AUK, BKH, BNS)
4		Starter Relay 2 (For engine code AUK, BKH, BNS) Brake Booster Relay (Not applicable for engine code AUK, BKH)
5		Rear Window Defogger Relay
6		Load Reduction Relay
8		Horn Relay
4		Brake Booster Relay (Not applicable for engine code AUK, BKH)

Main Fuse

The main fuse is located on the battery positive post, the fuse is numbered “S88” and has an amperage rating of 150 amps. The battery is located in the plenum chamber on right side of engine compartment.