Audi A8 (D3 / 4E, 2002 - 2010) fuses and relays

The A8 is a luxury car manufactured by Audi AG in Neckarsulm, Germany, the successor to the V8. In this article, we will take a detailed look at the fuse box diagrams for the Audi A8 (D3 / 4E) of the 2nd generation of  2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009  of release.

Here you will find the locations and photos of distribution boxes. Separately, we note the fuse responsible for the fuel pump and cigarette lighter.

In the engine compartment

It is located in the center of the engine compartment behind the lining.

Diagram
No.	Description	A
1	not used
2	secondary air pump	50/60/80
	Or
	glow plug
3	secondary air pump	50/60/80
	Or
	glow plug
4	not used
5
6
7
R1	Glow plug relay
	Secondary air pump relay
R2	Glow plug relay Main relay Secondary air pump relay
R3	Glow plug relay Secondary air pump relay Main relay
R4	not used

In the passenger compartment

There are two fuse distribution boxes and two relay boards here.

Fuse box #1

Located on the driver's side at the end of the dashboard behind a plastic cover.

General view.

Diagram of the fuse box No. 1 on the driver's side
No.	A	Purpose
1	5	garage door opener (HomeLink)
2	5	parking assistance (acoustic parking system)
3	5
4	10	automatic headlight beam throw adjustment
5	5	instrument cluster
6	10	steering column electronics control unit
7	5	diagnostic plug
8	5
9	5	electronic stability program (ESP)
10	5	instrument cluster
11	-	is absent
12	5	brake light switch
13	10	telephone
14	-	is absent
15	5	driver identification system control unit
16	-	is absent
17	5	distance maintenance (adaptive cruise control)
18	5	heated windshield washer jets
19	-	is absent
20	5	tire pressure monitoring system
21	-	is absent
22	5	brake light switch
23	5	telepassport
24	15	sound signal
25	40	wiper
26	-	is absent
27	25	electronic stability program (ESP)
28	-	is absent
29	10	lighting switches
30	-	is absent
31	30	onboard power supply control unit, front right lighting
32	-	is absent
33	25	additional space heater for hoi rear left
34	-	is absent
35	-	is absent
36	-	is absent
37	-	is absent
38	30	onboard power supply control unit, lighting front left
39	7.5	front left door control unit
40	25	steering column adjustment
41	7.5	rear left door control unit
42	25	start identification/permission control unit
43	-	is absent
44	-	is absent

Fuse box #2

Located on the passenger side behind a plastic cover.

Assigment of fuses in the passenger side
No.	A	Description
1	5	electromechanical parking brake
2	10	air conditioning
3	5	shift gate, PN-lock
4	15	automatic transmission (multitronic)
5	15	engine management
6	15	lambda probes
7	15/10	lambda probes/high pressure valve
8	10	engine management, auxiliary water pump
9	5	air conditioning, instrument panel keys
10	10	air suspension (adaptive air suspension)
11	5	light and rain sensor
12	5	display/control unit front
13	10	electronics in the ceiling
14	5	media player in front (CD player, DVD player, etc.)
15	5	battery-energy management system
16	5	heating crankcase ventilation system
17	5	jura valve electronics
18	-	is absent
19	5	diesel air mass sensor
20	5	air-conditioned seat
21	5/15	engine management (gasoline/diesel)
22	10	fuel cooling
23	5	electromechanical parking brake
24	10	onboard power supply control unit 2
25	15	automatic transmission
26	10	water pump/A/C valves, rear A/C controls
27	20	sliding roof panel
28	5	the engine control unit
29	15	Valve injectors
30	30	ignition coils
31	20/40	fuel pump right/fuel pump electronics (petrol)
32	5/10)	automatic transmission/multitronic
33	25	additional heating gel legroom rear right
34	20	heated/ventilated rear seats
35	20	Heated/ventilated front seats
36	20	Front cigarette lighter audi a8 d4
37	20/30	rear cigarette lighter and sockets
38	20	additional radiator fan
39	7.5	front right door control unit
40	15	brake booster
41	7.5	rear right door control unit
42	20	auxiliary heater/auxiliary heater
43	30	headlight cleaner
44	30	heater fan

Relay box #1

Located behind the trim at the passenger's feet.

Diagram
No.	Purpose	A
R1	Cooling Fan Relay Cooling Fuel Pump Relay Brake servomotor additional coolant pump Coolant circulation relay
R2	Starter relay
R3
R4	Fuel pump relay
	Or
	Power relay
R5	Headlight washer relay
1	Front right window lifter	30
	Or
	empty
2	Seat adjustment	30
3	blower	30
	Or
	Front right window lifter
	Or
	empty
4	Seat adjustment	30
5	not used
6

Relay box #2

Located behind the trim on the driver's side.

Diagram
No.	Purpose	A
1	ABS control unit	60
2	Leveling system	40
3	Power window	30/40
4	Seat adjustment	30
5		30
6	not used
7	not used
8	not used
R1	Adaptive Suspension Compressor Relay
R2	signal relay
R3	Terminal 15 supply voltage relay
R4	Washer heating relay
R5	Security system control unit (taxi)
R6	Terminal 75 supply voltage relay
R7	empty
R8	empty
R9	empty
R10	empty

In the luggage compartment

There are two blocks here.

Fuse box #1

Block number 1 is on the right side behind the skin.

Access example.

General view.

Diagram
No.	A	Description
1	20	fuel pump right (diesel)
2	20	fuel pump on the left (gasoline / diesel)
3	15	trailer socket
4	-	is absent
5	20	intelligent power module at the rear (light on the left)
6	10	intelligent power module at the rear (light on the right)
7	20	intelligent rear power module (trunk closing assist)
8	30	electromechanical parking brake, left motor
9	30	electromechanical parking brake, right motor
10	15	trailer control unit (light left)
11	15	trailer control unit (light on the right)
12	10	trailer control unit
A	40	Rear window heating
B	30/40	Rear seat adjustment
		Or
		Gasoline pump
C	30	Rear seat adjustment
D	15	Communication system
		Or
		Not used
R1	Heated rear window relay
R2	Power relay
R3	Fuel pump relay
1	150	Source of power
2	60	Radio
		Navigation system
		TV tuner
3	110	Rear window heating

Fuse box #2

The second block located on the left side.

General view.

Diagram
No.	A	Purpose
1	-	No
2	-	No
3	-	No
4	-	No
5	30	DSP amplifier
6	5	navigation
7	10	TV tuner
8	-	is absent
9	5	communication block
10	15	phone loudspeaker in hat rack
11	20	socket
12	5	auxiliary heater radio receiver