Audi A4 and S4 B9 / 8W (2020-2021) – fuse box
Audi A4 and S4 B9 / 8W – fuse box diagram
Year of production:2020, 2021.
The fuse for the cigarette lighter / power socket on the Audi A4 and S4 is fuse number 6 (black fuse panel C) in the fuse box in the driver / passenger footwell.
| Color | Amperes [A] |
|---|---|
| Black | 1 |
| Purple | 3 |
| Light brown | 5 |
| Brown | 7.5 |
| Red | 10 |
| Blue | 15 |
| Yellow | 20 |
| White or transparent | 25 |
| Green | 30 |
| Orange | 40 |
Location of the fuse box
Driver or front passenger footwell.
Left-hand drive vehicles: Located under the footrest.
Right-hand drive vehicles: behind a cover under the glove box.
Driver’s side fuse box
Trunk
It is located on the left side of the trunk behind the trim panel.
Fuse box diagrams
2020
Driver’s footwell (right-hand steering wheel)
Front passenger footwell (right-hand drive)
Assignment of fuses in the passenger compartment
| Number | Description |
|---|---|
| Brown panel A | |
| 1 | – |
| 2 | Engine components |
| 3 | Exhaust doors;
Fuel injectors; Radiator inlet; Connecting rod cover heating. |
| 4 | Vacuum pump;
Hot water pump; NOx sensor; Particulate sensor; Biodiesel sensor; Exhaust doors. |
| 5 | Brake light sensor |
| 6 | Engine valves;
Adjusting shaft each timing |
| 7 | Heated oxygen sensor;
Mass air flow sensor; Water pump. |
| 8 | The water pump;
High pressure pump; High pressure regulating valve; Temperature valve; Engine mount. |
| 9 | Hot water pump;
Engine relay. |
| 10 | Oil pressure sensor;
Oil temperature sensor. |
| 11 | Clutch pedal position sensor;
Engine start; The water pump. |
| 12 | Engine valves;
Mounting the engine. |
| 13 | Radiator fan |
| 14 | Fuel injectors;
Engine control module. |
| 15 | Ignition coils;
Heated oxygen sensor. |
| 16 | Fuel pump |
| Red panel B. | |
| 1 | Anti-theft alarm system |
| 2 | Engine control module |
| 3 | Lumbar support;
Front left seat electronics; Armchair massage. |
| 4 | Automatic transmission selection mechanism |
| 5 | Horn |
| 6 | Electromechanical parking brake |
| 7 | Gate control module |
| 8 | Electronic control module under the ceiling |
| 9 | Emergency call system |
| 10 | Airbag control module |
| 11 | Electronic Stability Control (ESC) |
| 12 | Diagnostic connector;
Light and rain sensor. |
| 13 | Air conditioning, heating and ventilation control system |
| 14 | Right front door control module |
| 15 | Air conditioning compressor |
| Black panel C. | |
| 1 | Front seat heating |
| 2 | Windshield wipers |
| 3 | Left headlight electronics |
| 4 | Panoramic glass sunroof / sliding / tilting sunroof |
| 5 | Left front door control module |
| 6 | Sockets |
| 7 | Right rear door control module |
| 8 | AWD control module |
| 9 | Right headlight electronics |
| 10 | Windscreen washers;
Headlight washers. |
| 11 | Left Rear Door Control Module |
| 12 | Auxiliary heating |
| Black panel D | |
| 1 | Front seat electronics;
Seat ventilation; Rearview mirror; Rear air conditioning, heating and ventilation control system; Windshield defogger; CAN diagnostics. |
| 2 | CAN gateway;
Air conditioning, heating and ventilation control system. |
| 3 | Exhaust sound tuning;
Sound actuator. |
| 4 | Clutch pedal position sensor |
| 5 | Engine start;
Emergency shutdown. |
| 6 | CAN gateway |
| 7 | USB charging port |
| 8 | Homelink (garage door opener) |
| 9 | Adaptive cruise control;
Distance adjustment. |
| 10 | – |
| 11 | Video camera |
| 12 | Matrix LED headlight and right-hand LED headlight |
| 13 | Matrix LED headlight and left LED headlight |
| 14 | Transmission fluid cooling valve |
| 15 | Alarm;Loudspeeker sysetm. |
| Red panel E. | |
| 1 | Ignition coils |
| 2 | Compressor clutch, CNG system |
| 3 | – |
| 4 | – |
| 5 | Left headlight |
| 6 | Automatic Transmission |
| 7 | Instrument panel |
| 8 | Air conditioning system (fresh air blower) |
| 9 | Right headlight |
| 10 | Dynamic steering |
| 11 | Engine start |
Driver’s side cockpit
Assignment of fuses in the cockpit on the driver’s side
| Number | Description |
|---|---|
| 1 | Opening and Starting the Vehicle (NFC) |
| 2 | Audi Phonebox;
USB port. |
| 3 | – |
| 4 | Head-up display |
| 5 | Audi music interface;
USB charging port. |
| 6 | Front air conditioning controls |
| 7 | Steering column lock |
| 8 | Central display |
| 9 | Instrument cluster |
| 10 | Volume control |
| 11 | Light switch |
| 12 | Steering column electronics |
| 13 | Particulate sensor for the air conditioning system |
| 14 | Infotainment system |
| 15 | – |
| 16 | Steering wheel heating;
Steering column electronics. |
Left side of the trunk
Assignment of fuses in the trunk
| Number | Description |
|---|---|
| Black panel A | |
| 1 | – |
| 2 | Windshield defroster |
| 3 | Windshield defroster |
| 4 | – |
| 5 | Suspension control |
| 6 | Automatic Transmission |
| 7 | Rear window defogger |
| 8 | Rear seat heating |
| 9 | Rear lights on the left |
| 10 | Airbag module |
| 11 | Electric trunk lid;
Fuel filler flap; Comfort system control module. |
| 12 | Electric boot lid lock;
Fuel filler flap. |
| 13 | Electric trunk lid. |
| Red panel B. | |
| 6 | Electric compressor |
| Brown panel C. | |
| 1 | External antenna |
| 2 | Audi Phonebox |
| 3 | Lumbar support;
Front right seat electronics; Armchair massage. |
| 4 | Audi side assistant |
| 5 | – |
| 6 | Tire pressure monitor |
| 7 | Opening and starting the vehicle (NFC) |
| 8 | Parking heater radio receiver;
Intelligent module (fuel tank). |
| 9 | – |
| 10 | TV tuner;
CAN gateway. |
| 11 | Additional battery module |
| 12 | Homelink (garage door opener) |
| 13 | Rear view camera;
Peripheral cameras. |
| 14 | Right rear lights |
| 15 | – |
| 16 | Airbag module;
Right seat belt pretensioner. |
| Red panel E. | |
| 1 | – |
| 2 | – |
| 3 | AdBlue |
| 4 | – |
| 5 | Trailer hitch (right light) |
| 6 | – |
| 7 | Towbar |
| 8 | Trailer hitch (left light) |
| 9 | Trailer hitch (socket) |
| 10 | Sports differential |
| 11 | Exhaust gas treatment, AdBlue |
2021
Driver’s footwell (right-hand steering wheel)
Front passenger footwell (right-hand drive)
Assignment of fuses in the passenger compartment
| Number | Description |
|---|---|
| Brown panel A | |
| 1 | Catalyst heating |
| 2 | Engine components |
| 3 | Exhaust doors;
Fuel injectors; Radiator inlet; Connecting rod cover heating. |
| 4 | Vacuum pump;
Hot water pump; NOx sensor; Particulate sensor; Biodiesel sensor; Exhaust doors. |
| 5 | Brake light sensor |
| 6 | Engine valves;
Camshaft adjustment |
| 7 | Heated oxygen sensor;
Mass air flow sensor; Water pump. |
| 8 | The water pump;
High pressure pump; High pressure regulating valve; Temperature valve; Engine mount. |
| 9 | Hot water pump;
Engine relay. 48V drive system generator; 48V water pump. |
| 10 | Oil pressure sensor;
Oil temperature sensor. |
| 11 | Clutch pedal position sensor;
Engine start; The water pump; 48V drive system generator; 12 V drive system generator. |
| 12 | Engine valves;
Mounting the engine. |
| 13 | engine cooling |
| 14 | Fuel injectors;
Engine control module. |
| 15 | Ignition coils;
Heated oxygen sensor. |
| 16 | Fuel pump |
| Red panel B. | |
| 1 | Anti-theft alarm system |
| 2 | Engine control module |
| 3 | Lumbar support;
Front left seat electronics; Armchair massage. |
| 4 | Automatic transmission selection mechanism |
| 5 | Horn |
| 6 | Electromechanical parking brake |
| 7 | CAN gate control module |
| 8 | Electronic control module under the ceiling |
| 9 | Emergency call system |
| 10 | Airbag control module |
| 11 | Electronic Stability Control (ESC);
ABS. |
| 12 | Diagnostic connector;
Light and rain sensor. |
| 13 | Air conditioning, heating and ventilation control system |
| 14 | Right front door control module |
| 15 | Air conditioning compressor |
| 16 | Brake pressure reservoir |
| Black panel C. | |
| 1 | Front seat heating |
| 2 | Windshield wipers |
| 3 | Left headlight electronics |
| 4 | Panoramic glass sunroof / sliding / tilting sunroof |
| 5 | Left front door control module |
| 6 | Sockets |
| 7 | Right Rear Door Control Module;
Right rear window actuator. |
| 8 | AWD Control Module (4WD) |
| 9 | Right headlight electronics |
| 10 | Windscreen washers;
Headlight washers. |
| 11 | Left Rear Door Control Module |
| 12 | Auxiliary heating |
| Black panel D | |
| 1 | Front seat electronics;
Seat ventilation; Rearview mirror; Rear air conditioning, heating and ventilation control system; Windshield defogger; CAN diagnostics. |
| 2 | CAN gateway;
Air conditioning, heating and ventilation control system. |
| 3 | Sound generator |
| 4 | Clutch pedal position sensor |
| 5 | Engine start;
Emergency shutdown. |
| 6 | CAN gateway;
Traffic Information System (TMC). |
| 7 | USB charging port |
| 8 | Homelink (garage door opener) |
| 9 | Adaptive cruise control;
Distance adjustment. |
| 10 | – |
| 11 | Video camera |
| 12 | Matrix LED headlight and right-hand LED headlight |
| 13 | Matrix LED headlight and left LED headlight |
| 14 | Transmission fluid cooling valve |
| 15 | Alarm;
Loudspeeker sysetm. |
| Red panel E. | |
| 1 | Ignition coils |
| 2 | Air conditioning compressor |
| 3 | – |
| 4 | – |
| 5 | Left headlight |
| 6 | Automatic Transmission |
| 7 | Instrument panel |
| 8 | Air conditioning system (fresh air blower) |
| 9 | Right headlight |
| 10 | Dynamic steering |
| 11 | Engine start |
Driver’s side cockpit
Assignment of fuses in the cockpit on the driver’s side
| Number | Description |
|---|---|
| 1 | Opening and Starting the Vehicle (NFC) |
| 2 | Telephone;
Charger for mobile devices. |
| 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 | Particulate sensor for the air conditioning system |
| 14 | Infotainment system |
| 15 | – |
| 16 | Steering wheel heating |
Left side of the trunk
Assignment of fuses in the trunk
| Number | Description |
|---|---|
| Black panel A | |
| 1 | – |
| 2 | Windshield defroster |
| 3 | Windshield defroster |
| 4 | – |
| 5 | Suspension control |
| 6 | Automatic Transmission |
| 7 | Rear window defogger |
| 8 | Rear seat heating |
| 9 | Rear lights on the left |
| 10 | Airbag module |
| 11 | Central lock |
| 12 | Electric trunk lid;
Fuel filler flap. |
| Red panel B. | |
| 6 | Electric compressor;
Battery power cut. |
| Brown panel C. | |
| 1 | – |
| 2 | Telephone;
The function of charging mobile devices – USB. |
| 3 | Lumbar support;
Front right seat electronics; Armchair massage. |
| 4 | Audi side assistant |
| 5 | – |
| 6 | Tire pressure monitor |
| 7 | Opening and starting the vehicle (NFC) |
| 8 | Parking heater radio receiver;
Intelligent module (fuel tank). |
| 9 | – |
| 10 | TV tuner;
CAN gateway. |
| 11 | Additional battery module |
| 12 | Homelink (garage door opener) |
| 13 | Rear view camera;
Peripheral cameras. |
| 14 | Right rear lights |
| 15 | – |
| 16 | Airbag system |
| Red panel E. | |
| 1 | – |
| 2 | – |
| 3 | AdBlue |
| 4 | – |
| 5 | Trailer hitch (right light) |
| 6 | – |
| 7 | Towbar |
| 8 | Trailer hitch (left light) |
| 9 | Trailer hitch (socket) |
| 10 | Sports differential;
4-wheel drive. |
| 11 | Exhaust gas treatment, AdBlue |