Audi A4 (B7, 2004 - 2007) fuses and relays

A4 B7 - the third generation of the mid-size car of the German company Audi, model range from 2004 to 2007. It is an updated model B6. In this material, we will analyze in detail the fuse diagrams of the 3rd generation Audi A4 (B7)  2004, 2005, 2006, 2007, 2008, 2009  with gasoline and diesel engines 1.6 8V, 1.8 20V turbo, 1.9 TDI, 2.0 FSI, 2.4 V6 , 2.5TDI V6, 3.0 V6, 4.2 V8.

Here you will find the locations and photos of the mounting blocks. Separately, we note the fuses responsible for the cigarette lighter and fuel pump.

General arrangement

Location of electronic components.

No.	Component
1	Air conditioning control unit - in the heater control panel - functions: Rear window defroster, front seat heaters Steering wheel heater
2	A/C/Heater Fan Control Unit - Fan Unit
3	Aerial Select Control Unit (Sedan with 'Concert II/Symphony II' Audio System) - Rear Dome Panel, Center
4	Antenna Booster (Sedan with 'ChorusII' Audio System) - Rear Dome Panel, Center
7	Collision sensor, driver's side - engine compartment
8	Crash sensor, passenger side - engine compartment
9	Vehicle tilt sensor (anti-theft system) - in the multifunction control unit2
10	Anti-Theft Alarm - Luggage Compartment, Behind Right Trim Panel
11	Volume change sensor (anti-theft system) - front interior lamp
12	Audio output amplifier - luggage compartment, behind right trim panel
13	Additional heater control unit - behind the arch of the left front wheel
14	Accumulator battery
15	Clock synchronization unit (with digital multifunction display) - behind the rear bumper
16	Diagnostic connector (DLC) - under the dashboard, on the driver's side
17	Diagnostic unit - on the dashboard
18	Door Function Control Module, Front Left (Central Locking/Door Mirror/Power Window) - Door
19	Door Function Control Module, Front Right (Central Locking/Door Mirror/Power Window) - Door
20	Door function control unit, rear left (central lock/power window) - door
21	Door function control unit, rear right (central lock/power window) - door
22	Cooling fan motor control unit - on the radiator
23	Fuse/Relay Boxes Behind Dashboard
24
25
26
27	Fuse/Relay Box 5, Dashboard - Taxi
28	Fuse/Relay Box, 6-Taxi Dashboard
29	Fuse/Relay Box, Engine Compartment - Under ECM/TCM
30	Main fuse (150A) - battery
31	Headlight control unit, left (models with xenon headlights)

In the underhood space

The block is located on the right side of the engine compartment under the ECM / TCM.

General view (removed for clarity).

Diagram
Diesel engines
No.	Description	A
F1	Engine Management System, Stop Lamp Switch (Brake Pedal Position Sensor)	15
F2	glow plugs	60/80
F3	Automatic transmission control system (6-speed automatic transmission / Multitronic)	15
F4	glow plugs	60
1	Fuel pump relay
2	Transmission control relay (Multitronic)
3	Glow plug relay
4	Engine management relay
5	Start Inhibit Switch Relay/Reversing Lamp Relay (Multitronic)
Petrol engines
No.	Decryption	A
F1	Engine Management System, Stop Lamp Switch (Brake Pedal Position Sensor)	15
F2	Exhaust air pump motor (if equipped)	40
F3	Automatic transmission control system (6-speed automatic transmission / Multitronic)	15
1	Coolant heater relay (V6) (if equipped)
2	Transmission control relay (Multitronic)
3	Exhaust air pump relay
4	Coolant pump motor control unit (AMM/BDV) (if equipped)
5	Start inhibit switch relay (if equipped)

In the passenger compartment

There are four fuse blocks in the cabin space. The main cabin unit is located at the end of the dashboard on the driver's side.

Fuse box

General form

Diagram
No.	A	Purpose
1	10	air conditioning
2	5	footwell lights
3	5	Heated windshield washer jets
4	5	cooling fan
5	10	telephone, engine oil level sensor, multifunction switches, heated rear seats, rear window shade, automatic transmission (shift gate)
6	5	air conditioning (air quality assessment sensor), pressure sensor
7	10	Electronic Stability Program (ESP), Brake Switch, Clutch Pedal Sensor, Steering Angle Sensor
8	5	telephone
9	15	brake booster (vacuum pump)
10	5	automatic headlight range adjustment. Adaptive light (turning light) right
11	-	empty
12	10	diagnostic socket
13	10	steering column module
14	10	brake lights
15	10	instrument cluster, navigation system
16	5	garage door opener
17	10	parking assistance, ride height control, tire pressure monitoring, rain/light sensor
18	5	Adaptive light (turning light) on the left
19	15	fog light
20	empty
21		is absent
22	15	driver/front passenger door
23	15	rear doors
24	20	comfortable electrical equipment with central control
25	30	heater fan
26	30	rear window heating
27	30	trailer socket (control unit)
28	20	fuel module (fuel pump fuse), auxiliary diesel pump
29	-	is absent
30	20	sliding roof panel
31	15	automatic transmission, diagnostic socket, automatically shielded interior mirror
32	20	trailer socket
33	15	audi b7 cigarette lighter fuse
34	-	is absent
35	20	socket in trunk
36	30	wiper
37	30	windshield washer pump and headlight cleaners
38	15	Comfort electrical system with central control, trunk release
39	20	radio system
40	25	sound signal
41	30	heater
42	25	electronic stability program (ESP)
43	15	engine management
44	35	seat heating

Additional relay blocks

Located behind the front trim on the driver's side. To access, you need to remove the lining of the steering column space.

Relay box #1
No.	Purpose	A
F1	empty	-
F2	Thermal fuse for electric rear window blind	10
F3	empty	-
F4	Thermal fuse for the electric drive of the rear windows	30
F5	Power seats (adjustable lumbar support)	10
F6	Thermal fuse for electric front windows	30
F7	Trailer electrical connector	30
1	Fuel pump relay - gasoline (fuel module, fuel pump relay)
2	Power steering (Servotronic) control unit (if equipped)
3	Horn relay (dual tone)
4	Brake Booster Vacuum Pump Relay (If Equipped)
5	empty
6	Ignition Auxiliary Relay
7	empty
8	empty
9	empty

Relay box #2
No.	Decryption	A
A	empty	-
B	Optional equipment
C	empty	-
D	empty	-
E	Anti-lock braking system ABS (ABS)	50
F	Control unit 1 cooling fan motor	40/60
G	Service vehicles	10
H	Cooling Fan Motor Control Module 2 - If Equipped
1	empty
2	empty
3	empty
4	Control unit 3 for the taxi-hands-free alarm system

Relay box #3
General form.
Diagram.
No.	Purpose	A
A	Additional heater - 2003	30
C	Coolant heater	40
B		60
1	empty
2	Coolant Heater Relay 2 - High Power
3	Coolant Heater Relay 1 - Low Power