Audi A4 B9 was produced in 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023 and 2024 with the designations B9 and 8W . During this time, the model has undergone restyling. In this article you can find a description of the fuses and relays of the Audi A4 B9 with diagrams, their locations and photo examples of execution. Let’s highlight the fuse responsible for the cigarette lighter.
Blocks in the cabin
Fuse and relay block
In the car interior, the fuse and relay box is located on the left side, under the dashboard.
Left-hand drive machines
Right-hand drive vehicles
| № | Description |
|---|---|
| Panel A (brown) | |
| 1 | Catalytic converter heating |
| 2 | Engine components |
| 3 | Exhaust doors, fuel injectors, air intake, engine heater |
| 4 | Vacuum pump, hot water pump, NOx sensor, particulate sensor, biodiesel sensor, exhaust door |
| 5 | Brake light sensor |
| 6 | Engine valves, camshaft adjustment |
| 7 | Heated oxygen sensors, mass air flow sensor, water pump |
| 8 | Water pump, high pressure pump, high pressure regulator valve, temperature valve, engine mount |
| 9 | Hot water pump, engine relay, 48V starter generator, 48V water pump |
| 10 | Oil pressure sensor, oil temperature sensor |
| 11 | Clutch position sensor, 48V starter generator, water pump, 12V starter generator |
| 12 | Engine valves, engine mount |
| 13 | Engine cooling |
| 14 | Fuel injectors, drive system control module |
| 15 | Ignition coils, heated oxygen sensors |
| 16 | Fuel pump |
| № | Description |
|---|---|
| Panel B (red) | |
| 1 | Anti-theft system |
| 2 | Drive system control module |
| 3 | Front left seat electronics, lumbar support, massage seat |
| 4 | Automatic transmission selector lever |
| 5 | Warning |
| 6 | Parking brake |
| 7 | Diagnostic interface (gateway control module) |
| 8 | Roof electronics control module |
| 9 | Emergency call and communication control module |
| 10 | Airbag control module |
| 11 | Electronic Stability Control (ESC), Anti-lock Braking System (ABS) |
| 12 | Diagnostic connector, light/rain sensor |
| 13 | Climate control system |
| 14 | Right front door control unit |
| 15 | Climate control compressor |
| 16 | Brake system receiver |
| № | Description |
|---|---|
| Panel C (black) | |
| 1 | Heated front seats |
| 2 | Janitors |
| 3 | Left headlight electronics |
| 4 | Panoramic glass roof/sliding/tilting sunroof |
| 5 | Left front door control unit |
| 6 | 12 volt socket, cigarette lighter |
| 7 | Right rear door control unit, right rear window regulator |
| 8 | All-wheel drive (AWD) control module |
| 9 | Right headlight electronics |
| 10 | Windshield washer/headlight washer system control module |
| 11 | Left rear door control module, left rear power window |
| 12 | Autonomous heater |
Fuse No. 6 is responsible for the operation of the cigarette lighter.
| № | Description |
|---|---|
| Panel D (black) | |
| 1 | Front seat electronics, seat ventilation, rear-view mirror, rear climate control panel, heated windshield, diagnostic connector |
| 2 | Diagnostic interface, on-board network control module |
| 3 | Sound generator |
| 4 | Clutch position sensor |
| 5 | Engine start, emergency shutdown |
| 6 | Diagnostic connector, traffic information antenna (TMC) |
| 7 | USB connection |
| 8 | Garage door opener |
| 9 | Audi adaptive cruise control, adaptive distance control |
| 11 | Front camera |
| 12 | Right headlight |
| 13 | Left headlight |
| 14 | Transmission fluid cooling / Rear window wiper |
| 15 | Alarm and speakerphone system |
| № | Description |
|---|---|
| Panel E (red) | |
| 1 | Ignition coils |
| 2 | Climate control compressor |
| 5 | Left headlight |
| 6 | Automatic transmission |
| 7 | Dashboard |
| 8 | Climate control fan |
| 9 | Right headlight |
| 10 | Dynamic steering wheel |
| 11 | Starting the engine |
Fuse block
Another fuse block is installed on the left side of the instrument panel.
| № | Marking |
|---|---|
| 1 | Convenient access and launch authorization control module (NFC) |
| 2 | Audi phone, USB connector |
| 3 | – |
| 4 | Projection display |
| 5 | Audi music interface, USB connection |
| 6 | Front climate control panel |
| 7 | Steering column lock |
| 8 | Central display |
| 9 | Instrument panel |
| 10 | Volume control |
| 11 | Light switch, switch module |
| 12 | Steering column electronics |
| 13 | Particulate sensor for climate control system |
| 14 | Infotainment system |
| 15 | – |
| 16 | Steering column electronics. |
Block in the trunk
This fuse box is located in the luggage compartment on the left side, behind the trim.
| № | Appointment |
|---|---|
| Panel A (black) | |
| 2 | Windshield heater |
| 3 | Windshield heater |
| 5 | Suspension control |
| 6 | Automatic transmission |
| 7 | Heated rear window |
| 8 | Rear seat heating |
| 9 | Left tail lights |
| 10 | Airbag, driver’s seat belt tensioner control module |
| 11 | Trunk lid lock, fuel filler flap lock, comfort system control unit |
| 12 | Luggage compartment lid |
| Panel B (red) | |
| 6 | Battery power interruption / Electric compressor |
| Panel C (brown) | |
| 1 | External antenna |
| 2 | Audi phone booth |
| 3 | Right front seat electronics, lumbar support, massage seat |
| 4 | Side assistance |
| 6 | Tire pressure monitoring system |
| 7 | Convenient access and launch authorization control module (NFC) |
| 8 | Additional heating, tank module |
| 10 | TV tuner, data exchange module and telematics control |
| 11 | Auxiliary battery control module |
| 12 | Garage door opener |
| 13 | Rear view camera, peripheral cameras |
| 14 | Right rear lights |
| 16 | Airbag, front passenger seat belt tensioner control module |
| Panel E (red) | |
| 3 | Exhaust treatment (Adblue) |
| 5 | Right trailer light |
| 7 | Trailer coupling |
| 8 | Left trailer light |
| 9 | Trailer socket |
| 10 | All-wheel drive control module, sports differential |
| 11 | Exhaust treatment (Adblue) |