Audi A4 (B8) – fuse and relay

Audi A4 (B8) is the fourth generation of the Audi A4. Released in 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 and 2015. This publication provides a description of the fuses and relays of the audi a4 b8 with diagrams and photographs of the boxes, as well as their locations. Let’s highlight the fuse responsible for the cigarette lighter.

Audi A4 B8

Location

Location of fuses a4 b8

Passenger compartment

Left dashboard fuse box

To access the fuses, open the door and remove the cover. It will look something like this. An example of access is in our video at the end of the article.

real photo 2

Diagram

diagram Audi A4 B8

Designation for cars audi a4 b8 before 2010

1(5A) Power steering control module
2(5A) Clutch pedal position sensor
3(5A) Garage door remote control control module
4(10A) Lane guidance control module
5(5A) Heater air purity sensor
6(5A) RH headlamp
7(5A) LH headlamp
8(5A) Onboard supply control unit
9(5A) Interior rearview mirror with dimming
10(5A) Gear shift control module
11(5A) Heated windscreen washer nozzles
12(5A) Air conditioning system
13(5A) Coolant pump motor
14(5A) Clutch pedal position sensor
15(20A / 25A) Fuel pump control unit
16(5A) Coolant pump motor
17(30A) Onboard supply control unit
18(10A) ABS control module
19(25A) Horn
20(30A) Door function control units
21(30A) Windshield wiper motor
22(25A) ABS control module
23(15A) Door function control units
24(5A) Rain and light sensor
25
26
27(10A) Power seats
28(35A) Power steering control module
29(5A) Antenna amplifier
30(35A) Onboard supply control unit
31(20A) Onboard supply control unit
32(30A) Onboard supply control unit
33(20A) Sunroof control module
34(30A) Onboard supply control unit
35(20A) Sun shade
36(5A) Anti-theft system

Designation for cars audi a4 b8 from 2010

F1(5A) Power steering control module
F2
F3(5A) Garage door remote control control module
F4(10A) Lane guidance control module
F5(5A) Heater air purity sensor
F6(5A) RH headlamp
F7(5A) LH headlamp
F8(5A) onboard supply control unit
F9(5A) Cruise control module
F10(5A) Clutch pedal position sensor, clutch sensor control module,
F11(5A) Heated windscreen washer nozzles
F12(5A) Air conditioning system
F13(5A) Telephone connector
F14(5A) Hazard warning light button, airbag control module, seat occupied recognition,
F15(25A) ABS control module
F16(40A) Starter
F17(5A) Interior rearview mirror with dimming
F18(5A) Clutch pedal position sensor
F19(20A / 25A) Fuel pump control unit
F20(10A) Coolant pump motor
F21(15A/30A)
F22(10A) ABS control module
F23(25A) Horn
F24(30A) Door function control units
F25(30A) Windshield wiper motor
F26(25A) ABS control module
F27(15A) Door function control units
F28(5A) Rain and light sensor.
F29
F30
F31(10A) Power seats
F32(35A) Power steering control module
F33
F34(35A)
F35(20A)
F36(30A)
F37(20A) Sunroof control module
F38(30A)
F39(20A) Sun shade
F40(5A) Anti-theft system

Right dashboard fuse board

fuse on the right

Assignment

1 ST1
2
3
4
5(5A) Steering column control module
6(5A) ESP switch
7(5A) Diagnostic connector (DLC)
8(5A) CAN data bus, gateway control unit
9(5A) Coolant heater
10
11
12
1(5A) Audio system – ST2
2(5A) Multifunction switch
3(5A / 20A)
4(5A) Instrument cluster control module
5(5A) CAN data bus, gateway control unit
6(5A) Keyless entry and start system
7(5A) Headlamp switch
8(40A) A / C / heater blower motor control module
9(5A) Steering column lock control module
10(10A) A / C control module
11(10A) Diagnostic connector (DLC)
12(5A) Steering column control module

Additional box

6-pin rack-mount connection box

Located in the driver’s footwell, behind the side trim.

F. Thermal fuse 1 per. seat lane. passage. -S46-, 15 A
G. Thermal fuse 1 per. seat drives. -S44-

Relay and fuse box with used on-board network

Installation location of the relay / fuse box with a used on-board network under the panel on the driver’s side.

block a4Description

A. Fuse 1 used ABS -S123-, 40 A
1. Not used
2. Relay of the circulation pump -L 60-
2. Horn relay -J413-
2. Relay for vacuum pump -J318-
2. Relay, inside rearview mirror. view with automatic dimming function -J910-
3. Power relay cl. 15. J329-
4. Used remote control. anti-theft alarm for taxi -J601-

Engine compartment

Box in the center of the plenum chamber

block a4 b8

Designation

  1. 40A, 60A – Fan control system 400 W. Fan control system 600 W
  2. 40A – Fan control 400 W

Switchgear fuse board

Diagram

fuses near the motor

Protected components

  • A. Used automatic glow plug system (until 2011)
  • A. Power Relay for Engine Components
  • B. Starter relay (up to 2011)
  • B. Starter relay 2
  • C. Relay pump sec, air
  • D. Power relay cl. 30 (until 2011)
  • D. Motronic Power Relay
  • E. Fuel relay pump
  • E. Relay add. fuel pump
  • E. Coolant recirculation relay after engine shutdown
  • E. Relay add. pump system. cooling
  • E. Gearbox cooling circuit relay
  • E. Power relay for motor components 2
  • F. not used

fuses for cars up to October 2011 release

115 AAutomatic transmission control unit. Mechatronic unit for dual clutch gearbox
25 AEngine oil level and temperature sensor
35 AEngine control unit. Air mass meter
45aEngine control unit
510A, 15A, 20AAir mass meter. Automatic glow plug control unit. Secondary air pump relay. Low power heating relay. High power heating relay. Solenoid valve for boost pressure limitation. Crankcase ventilation heating resistor. Solenoid valve 1 of the adsorber. Secondary air control valve. solenoid valve for the left electro-hydraulic engine support. solenoid valve for the right electro-hydraulic engine support. The valve of the system of changing the geometry of the intake manifold. Air filter bypass flap valve -. Fuel pressure control. Fuel metering valve. Secondary air control valve 2-. Exhaust gas recirculation cooler changeover valve. Oil pressure relief valve. Fuel system diagnostic pump
615 AEngine control unit
710A, 15Aactuator 1 of the variable valve timing system. actuator 9 of the variable valve timing system. Solenoid valve for boost pressure limitation. Solenoid valve 1 of the adsorber – the solenoid valve of the left electro-hydraulic engine support. solenoid valve for the right electro-hydraulic engine support. Valve 1 of the variable valve timing system. Valve 2 of the variable valve timing system. Charge air recirculation valve. Fuel pressure control-. Fuel metering valve. Intake manifold flap valve -N316-. Valve 1 of the exhaust camshaft adjuster -. Valve 2 of the exhaust camshaft adjuster. Climatronic coolant shut-off valve. Oil pressure relief valve. Fuel system diagnostic pump. Inflatable air cooling pump
810A, 5A, 20AExhaust gas recirculation cooler pump -V400-. Ignition coil 1 with output stage. Ignition coil 2 with output stage. Ignition coil 3 with output stage. Ignition coil 4 with output stage. Ignition coil 5 with output stage. Ignition coil 6 with output stage
95A, 15A, 20ARelay for additional fuel pump. Heating element for lambda probe 1 after catalytic converter. Heating element for lambda probe 2 after catalytic converter
1010A, 15ALambda probe heating element. Heating element for lambda probe 2. Heating element for lambda probe 1 after catalytic converter
115 ARadiator fan control unit. Radiator fan control unit 2
125 AAir mass meter. Automatic gearbox control unit mechatronic for dual-clutch gearbox

from October 2011

115 AAutomatic gearbox control unit – mechatronic for dual clutch gearbox
25 AEngine oil level and temperature sensor
35 AEngine control unit
45 AEngine control unit
510A, 5AAir mass meter. Fuel pressure control. Fuel metering valve
615 AEngine control unit – Injector 2 cylinders 1, 2, 3, 4
7actuator 1, 2, 3, 4, 5, 6, 7, 8 of the variable valve timing system. Solenoid valve for boost pressure limitation. Solenoid valve 1 of the adsorber solenoid valve of the left electro-hydraulic engine support. solenoid valve for the right electro-hydraulic engine support. Valve 1 of the variable valve timing system. Valve 2 of the variable valve timing system. Charge air recirculation valve. Fuel pressure control.
810A, 15A, 5ANOx sensor 2. NOx sensor control unit 2
95 AVoltage regulator. Engine control unit
1010A, 15ALambda probe heating element
115 ARadiator fan control unit
125 AAutomatic transmission control unit
13not used
145A, 20AEngine Component Power Relay 2. Ignition Coil 1 with Output Stage.
155 APower steering control unit
1615 AThermostat for the parametric engine cooling system. Automatic glow plug control unit
1715 ALambda probe heater after catalytic converter

Luggage compartment fuse box

The box is located behind the right side trim. Item descriptions may differ from those shown.

Diagram

fuses in the trunk of audi

For cars up to 2010

ASedan: Not used
B
CSedan: Heated rear window relay
D
EAccessory Power Connector Relay
1(30A) Trunk lid control module
2
3(30A) Trunk lid control module
4(5A) Plug connector
5
6
7
8
9
10
11
12
13(5A) Tire pressure monitor control module
14(15A) Trailer control module
15(20A) Trailer control module
16(20A) Trailer control module
17(5A) Electric parking brake control module
18(15A) Suspension control module
19(30A) Electric parking brake control module
20(30A) comfort system
21(35A) 4WD electronic control module
22(30A) comfort system
23(20A) comfort system
24 (5A) vehicle location management system
25(15A / 30A) Accessory power connector
26(15A) Heated seat control module
27(7.5A) navigation system / radio
28(30A) Audio system
29(5A) Multifunction display control unit
30(30A) Auxiliary heater control module
31(30A) Electric parking brake control module
32(30A) Heated seats
33(30A) Door function control units
34(5A) Auxiliary heater remote control receiver
35(15A) Door function control units
36(5A) Rear view camera control module
37(15A) Accessory power connector
38(15A) Accessory power connector
39(15A) Accessory power connector
40(15A) Cigar lighter
41(5A) Self-parking control module
42
43(5A) Distance control module (cruise control)
44(15A) Rear window wiper motor
45(5A) Electric parking brake control module
46(5A) Lane change assist control unit
47(5A) Heated seats
48(5A) Hazard warning lights, airbag control module
49
50
51(10A/15A/25A)
52(10AL5A) Special vehicle equipment
53(5A / 15A) Automotive special equipment
54(10A) Special vehicle equipment
55(5A / 20A) Special vehicle equipment
56(10A) Special vehicle equipment
57(10A) Accessory power connector
58(10A) Special vehicle equipment
59(10A) Special vehicle equipment
60
61(40A) Heated rear window

from 2010

1not used
2not used
315A. 25AAlarm system control unit
415 AAlarm system control unit
55A, 15ASpecial signal control panel, Alarm system control unit
6Control panel for special signals. Alarm system control unit, Tachograph control unit. Male connector, 3-pin. Alarm memory
720 AControl unit for special vehicles
810 AAlarm memory
910 A12V socket
1010 AWalkie talkie dividing relay, walkie talkie relay
1110 AWalkie talkie dividing relay, walkie talkie relay
12not used
1330 ARear lid control unit 2 –
1415 ATrailer detection control unit
1520 ATrailer detection control unit
1620 ATrailer detection control unit
175 AAUTO HOLD button
1815 AControl unit for electronic shock absorber adjustment
1930 AElectromechanical parking brake control unit
2030 AConvenience system central control unit
2135 AAll-wheel drive control unit
2230 AConvenience system central control unit
2320 AConvenience system central control unit
245 AVehicle location system interface control unit
2530 ARear lid control unit
2615 ARight front seat ventilation control unit
2740 ARadio tape recorder. Phone transceiver – TV tuner. Mobile phone amplifier. Phone holder-. Male connector, 18-pin
2840 AVoltage regulator
2930 AInverter with socket, 12V
3030 AAdditional heater control unit
3130 AElectromechanical parking brake control unit
3230 ASwitch with adjustable rear left heated seat. Heated Rear Right Seat Switch with Adjustment
3330 ARight doors
345 AAuxiliary heater receiver
3515 ARight doors
3630 AAdditive dosing system control unit
3715 A12V socket
3815 A12V socket -. Inverter with socket, 12V – 230V
3915 A12V socket
4015 ACigarette lighter
41not used
425 APlug connector, 2-pin, in the backrest of the driver’s seat. Plug connector, 2-pin, in the backrest of the driver’s seat
437.5 APark assist control unit
4415 ARear window wiper motor
455 AElectromechanical parking brake button
465 ALane change assist control unit 2
475 ASwitch with adjustable rear left heated seat
485 ATrailer detection control unit. All-wheel drive control unit. Voltage regulator. Electromechanical parking brake control unit
49not used
50not used
5120A, 30ADigital audio system control unit. Radio cassette
527.5AElectronic information system control unit
535A, 7.5AControl unit for navigation system with CD drive. Radio tape recorder. Telephone transceiver -. TV tuner – Mobile phone amplifier. Phone holder-. Male connector, 18-pin
545 ARear view camera control unit
555 AMobile Phone Amplifier
56not used
57not used
58not used
59not used
60not used
6140 AHeated rear window relay – Heated rear window

The fuse number 40 at 15A is responsible for the cigarette lighter.

Additional Information

In this video you can see the locations of the main presented relay and fuse boxes.

Comments 1

  • 2010 Audi a4 b8, Fog lights stay on when car is off. I tried to turn the fog lights off by starting the engine and turning the light switch, but the fog lights stayed on. I went for a drive, 5 minutes into the drive, the horn turned on without me pressing it, and stayed on until the fuse burned out. I also lost power steering right after the horn started. I have disconnected the battery for now. what could have gone wrong in the car? would anyone be able to assist me?

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