Hello!,good morning. In this posting you will see a description of fuses and relays Audi A4 and S4 B9 / 8W (2017-2019) – fuse box
Include with pics of block diagrams along with their locations. Highlighted the cigarette lighter fuse (as the most common thing people look for).
Get tips on Assistance fuses, upgrading a fuse, and more.
Cigarette lighter / socket fuse on Audi A4 and S4 is fuse number 6 (black fuse panel C) in the fuse box in the driver’s / passenger’s footwell.
Location of the fuse box
Driver / front passenger footwell
Left-hand drive vehicles: It is located under the footrest.
Right-hand drive vehicles: behind the cover under the glove compartment.
Driver’s side cockpit
Trunk
It is located on the left side of the trunk behind the trim panel.
Fuse box diagrams
2017
Driver / front passenger footwell (LHD)
Front passenger footwell (RHD)
Fuse assignment in passenger compartment (legs) (2017)
| Number | Description |
|---|---|
| Brown panel A | |
| 1 | – |
| 2 | Mass air flow sensor;
Camshaft adjustment. |
| 3 | Exhaust doors;
Fuel injectors; Radiator inlet. |
| 4 | Vacuum pump;
Hot water pump; Particulate sensor; Biodiesel sensor. |
| 5 | Brake light sensor |
| 6 | Engine valves |
| 7 | Heated oxygen sensor;
Mass air flow sensor. |
| 8 | The water pump;
High pressure pump; High pressure regulating valve. |
| 9 | Hot water pump |
| 10 | Oil pressure sensor;
Oil temperature sensor. |
| 11 | Clutch pedal position sensor |
| 12 | Engine valves |
| 13 | Radiator fan |
| 14 | Fuel injectors |
| 15 | Ignition coils |
| 16 | Fuel pump |
| Red panel B. | |
| 1 | Anti-theft alarm system |
| 2 | Engine control module |
| 3 | Lumbar support |
| 4 | Automatic transmission selection mechanism |
| 5 | Horn |
| 6 | Electromechanical parking brake |
| 7 | Gate control module |
| 8 | Internal interior headlamps |
| 9 | – |
| 10 | Airbag control module |
| 11 | Electronic Stability Control (ESC) |
| 12 | Diagnostic connector;
Light and rain sensor |
| 13 | Climate control system |
| 14 | Right front door control module |
| 15 | Air conditioning compressor |
| Black panel C. | |
| 1 | Front seat heating |
| 2 | Wipers |
| 3 | Left head lighting electronics |
| 4 | Panoramic glass sunroof / sliding / tilting sunroof |
| 5 | Left front door control module |
| 6 | Sockets |
| 7 | Right rear door control module |
| 8 | – |
| 9 | Right headlight electronics |
| 10 | Windscreen washers;
Headlight washers. |
| 11 | Left Rear Door Control Module |
| Black panel D | |
| 1 | Seat ventilation;
Rearview mirror; Rear air conditioning system control. |
| 2 | Gate;
Climate control system. |
| 3 | Adjustment of actuator sound, exhaust sound |
| 4 | Clutch pedal position sensor |
| 5 | Engine start |
| 6 | – |
| 7 | – |
| 8 | Homelink |
| 9 | Adaptive cruise control |
| 10 | – |
| 11 | Video camera |
| 12 | Matrix LED headlight and right-hand LED headlight |
| 13 | Matrix LED headlight and left LED headlight |
| 14 | Rear window wiper |
| Red panel E. | |
| 1 | Ignition coils |
| 2 | Valves for natural gas tanks |
| 3 | – |
| 4 | – |
| 5 | Engine mount |
| 6 | Automatic gearbox |
| 7 | Instrument panel |
| 8 | Air conditioning system (blower) |
| 9 | – |
| 10 | Dynamic steering |
| 11 | Engine start |
Driver’s side cockpit
Driver’s side cockpit fuse assignment (2017)
| Number | Description |
|---|---|
| 1 | – |
| 2 | Telephone |
| 3 | – |
| 4 | Head-up display |
| 5 | Audi music interface |
| 6 | Front air conditioning controls |
| 7 | Steering column lock |
| 8 | Infotainment system display |
| 9 | Instrument cluster |
| 10 | Infotainment unit |
| 11 | Light switch |
| 12 | Steering column electronics |
| 13 | – |
| 14 | Infotainment system |
| 15 | – |
| 16 | Steering wheel heating |
Left side of the trunk
Fuse allocation in the left luggage compartment (2017)
| Number | Description |
|---|---|
| Black panel A | |
| 1 | – |
| 2 | Windshield defroster |
| 3 | Windshield defroster |
| 4 | – |
| 5 | Suspension control |
| 6 | Automatic gearbox |
| 7 | Rear window defogger |
| 8 | Rear seat heating |
| 9 | Rear lights |
| 10 | Left seat belt pretensioner |
| 11 | Central lock |
| 12 | Electric trunk lid |
| Red panel B. | |
| – | Not assigned |
| Brown panel C. | |
| 1 | – |
| 2 | Telephone |
| 3 | Lumbar support |
| 4 | Audi side assistant |
| 5 | – |
| 6 | – |
| 7 | – |
| 8 | – |
| 9 | – |
| 10 | – |
| 11 | – |
| 12 | Homelink |
| 13 | Rear view camera;
Peripheral cameras. |
| 14 | Right rear lights |
| 15 | – |
| 16 | Right seat belt pretensioner |
| Red panel E. | |
| 1 | – |
| 2 | Sound amplifier |
| 3 | AdBlue |
| 4 | – |
| 5 | Trailer hitch (right light) |
| 6 | – |
| 7 | Towbar |
| 8 | Trailer hitch (left light) |
| 9 | Trailer hitch (socket) |
| 10 | Sports differential |
| 11 | Ad Blue |
2018
Driver / front passenger footwell (LHD)
Front passenger footwell (RHD)
Assignment of fuses in the passenger compartment (footwell) (2018)
| Number | Description |
|---|---|
| Brown panel A | |
| 1 | – |
| 2 | Mass air flow sensor;
Camshaft adjustment; Charge air cooler pump. |
| 3 | Exhaust doors;
Fuel injectors; Radiator inlet. |
| 4 | Vacuum pump;
Hot water pump; Particulate sensor; Biodiesel sensor. |
| 5 | Brake light sensor |
| 6 | Engine valves;
Camshaft adjustment. |
| 7 | Heated oxygen sensor;
Mass air flow sensor. |
| 8 | The water pump
High pressure pump; High pressure regulating valve. |
| 9 | Hot water pump |
| 10 | Oil pressure sensor;
Oil temperature sensor. |
| 11 | Clutch pedal position sensor |
| 12 | Engine valves |
| 13 | Radiator fan |
| 14 | Fuel injectors |
| 15 | Ignition coils |
| 16 | Fuel pump |
| Red panel B. | |
| 1 | Anti-theft alarm system |
| 2 | Engine control module |
| 3 | Lumbar support |
| 4 | Automatic transmission selection mechanism |
| 5 | Horn |
| 6 | Electromechanical parking brake |
| 7 | Gate control module |
| 8 | Internal interior headlamps |
| 9 | – |
| 10 | Airbag control module |
| 11 | Electronic Stability Control (ESC) |
| 12 | Diagnostic connector;
Light and rain sensor |
| 13 | Climate control system |
| 14 | Right front door control module |
| 15 | Air conditioning compressor |
| Black panel C. | |
| 1 | Front seat heating |
| 2 | Wipers |
| 3 | Left head lighting electronics |
| 4 | Panoramic glass sunroof / sliding / tilting sunroof |
| 5 | Left front door control module |
| 6 | Sockets |
| 7 | Right rear door control module |
| 8 | All-wheel drive |
| 9 | Right headlight electronics |
| 10 | Windscreen washers;
Headlight washers. |
| 11 | Left Rear Door Control Module |
| Black panel D | |
| 1 | Seat ventilation;
Rearview mirror; Rear air conditioning system control. |
| 2 | Gate;
Air conditioning control system. |
| 3 | Adjustment of actuator sound, exhaust sound |
| 4 | Clutch pedal position sensor |
| 5 | Engine start |
| 6 | – |
| 7 | Rear USB charging port |
| 8 | Homelink |
| 9 | Adaptive cruise control |
| 10 | – |
| 11 | Video camera |
| 12 | Matrix LED headlight and right-hand LED headlight |
| 13 | Matrix LED headlight and left LED headlight |
| 14 | Rear window wiper |
| Red panel E. | |
| 1 | Ignition coils |
| 2 | Valves for natural gas tanks |
| 3 | – |
| 4 | – |
| 5 | Engine mount |
| 6 | Automatic gearbox |
| 7 | Instrument panel |
| 8 | Air conditioning system (blower) |
| 9 | – |
| 10 | Dynamic steering |
| 11 | Engine start |
Driver’s side cockpit
Driver’s side cockpit fuse assignment (2018)
| Number | Description |
|---|---|
| 1 | – |
| 2 | Telephone |
| 3 | – |
| 4 | Head-up display |
| 5 | Audi music interface;
USB charging port. |
| 6 | Front air conditioning controls |
| 7 | Steering column lock |
| 8 | Infotainment system display |
| 9 | Instrument cluster |
| 10 | Infotainment unit |
| 11 | Light switch |
| 12 | Steering column electronics |
| 13 | – |
| 14 | Infotainment system |
| 15 | – |
| 16 | Steering wheel heating |
Left side of the trunk
Fuse allocation in the left luggage compartment (2018)
| Number | Description |
|---|---|
| Black panel A | |
| 1 | – |
| 2 | Windshield defroster |
| 3 | Windshield defroster |
| 4 | – |
| 5 | Suspension control |
| 6 | Automatic gearbox |
| 7 | Rear window defogger |
| 8 | Rear seat heating |
| 9 | Rear lights |
| 10 | Left seat belt pretensioner |
| 11 | Central lock |
| 12 | Electric trunk lid |
| Red panel B. | |
| – | Not assigned |
| Brown panel C. | |
| 1 | – |
| 2 | Telephone |
| 3 | Lumbar support |
| 4 | Audi side assistant |
| 5 | – |
| 6 | – |
| 7 | – |
| 8 | Intelligent module (tank) |
| 9 | – |
| 10 | – |
| 11 | 12 V battery. |
| 12 | Homelink |
| 13 | Rear view camera; Peripheral cameras. |
| 14 | Right rear lights |
| 15 | – |
| 16 | Right seat belt pretensioner |
| Red panel E. | |
| 1 | – |
| 2 | Sound amplifier |
| 3 | AdBlue heating |
| 4 | – |
| 5 | Trailer hitch (right light) |
| 6 | – |
| 7 | Towbar |
| 8 | Trailer hitch (left light) |
| 9 | Trailer hitch (socket) |
| 10 | Sports differential |
| 11 | Ad Blue |
