In late 2002, the original Audi A8 was replaced by a modernized model – the D3/4E. It was produced in 2003, 2004, 2005, 2006, 2007, 2008, 2009, and 2010. Two changes were made during this time: the front grille and taillights were significantly redesigned. Our article describes the relay blocks and fuse circuits for the Audi A8 D3.

Assignment of relays and fuses in the Audi A8 D3

- Fuse box on left instrument panel;
- Relay and fuse box in engine compartment;
- Relay and fuse box behind the dashboard;
- Fuse box on right dashboard;
- Fuses on the shelf on the right;
- Fuse box at passenger’s feet;
- 8. 9. 10. – Blocks with relays and fuses in the trunk on the left and right sides.
Fuse box in the interior of the Audi A8 D3 left
It is located on the left side of the dashboard, behind a plastic cover.


Program description
| NO. | consumer | amplifier |
| 1 | Garage door opener (HomeLink) | 5 |
| 2 | Parking assistance system (acoustic parking system) | 5 |
| 3 | Parking assistance system (acoustic parking system) | 5 |
| 4 | automatic headlight range adjustment | 10 |
| 5 | instrument cluster | 5 |
| 6 | Steering column electronics control unit | 10 |
| 7 | Diagnostic system connector | 5 |
| 8 | Diagnostic system connector | 5 |
| 9 | Electronic Stability Program (ESP) | 5 |
| 10 | instrument cluster | 5 |
| 11 | absent | |
| 12 | brake light switch | 5 |
| 13 | phone | 10 |
| 14 | absent | |
| 15 | Driver identification system control unit | 5 |
| 16 | absent | |
| 17 | Keep your distance (Adaptive Cruise Control) | 5 |
| 18 | heated windshield washer nozzles | 5 |
| 19 | absent | |
| 20 | Tire pressure monitoring system | 5 |
| 21 | absent | |
| 22 | brake light switch | 5 |
| 23 | Telepass | 5 |
| 24 | sound signal | 15 |
| 25 | mat | 40 |
| 26 | absent | |
| 27 | Electronic Stability Program (ESP) | 25 |
| 28 | absent | |
| 29 | Light switch | 1 |
| 30 | absent | |
| 31 | On-board power control unit, right front lighting | 30 |
| 32 | absent | |
| 33 | Additional heating of the rear left trunk lid | 25 |
| 34 | absent | |
| 35 | absent | |
| 36 | absent | |
| 37 | absent | |
| 38 | On-board power control unit, front left lighting | 30 |
| 39 | Front left door control unit | 7.5 |
| 40 | Steering column adjustment | 25 |
| 41 | Rear left door control unit | 7.5 |
| 42 | Identification/Start Authorization Control Unit | 25 |
| 43 | absent | |
| 44 | absent |
Fuse box on the right side in the interior of the Audi A8 D3

Table with the purpose of the elements
| NO. | Intention | amplifier |
| 1 | electromechanical parking brake | 5 |
| 2 | air conditioning | 10 |
| 3 | Gear shift linkage, PN locking | 5 |
| 4 | Automatic gearbox (Multitronic) | 15 |
| 5 | Engine control | 15 |
| 6 | Lambda probes | 15 |
| 7 | Lambda probes/high pressure valve | 15/10 |
| 8 | Engine control, additional water pump | 10 |
| 9 | Air conditioning, buttons on the dashboard | 5 |
| 10 | Air suspension (adaptive air suspension) | 10 |
| 11 | Light and rain sensor | 5 |
| 12 | Front display/control unit | 5 |
| 13 | Electronics in the ceiling | 10 |
| 14 | Front media player (CD player, DVD player, etc.) | 5 |
| 15 | Battery power management system | 5 |
| 16 | heated crankcase ventilation system | 5 |
| 17 | Jura valve electronics | 5 |
| 18 | absent | |
| 19 | Mass air flow sensor for diesel engines | 5 |
| 20 | air-conditioned seat | 5 |
| 21 | Engine management (petrol/diesel) | 5/15 |
| 22 | Fuel cooling | 10 |
| 23 | electromechanical parking brake | 5 |
| 24 | On-board power control unit 2 | 10 |
| 25 | automatic transfer | 15 |
| 26 | Water pump/A/C valves, rear A/C control | 10 |
| 27 | Sliding and tilting roof panel | 20 |
| 28 | engine control unit | 5 |
| 29 | Valve injectors | 15 |
| 30 | ignition coils | 30 |
| 31 | Right fuel pump/fuel pump electronics (petrol) | 20/40 |
| 32 | Automatic gearbox/Multitronic | 5/10) |
| 33 | additional heating gel for the right rear footwell | 25 |
| 34 | heated/ventilated rear seats | 20 |
| 35 | Heated/ventilated front seats | 20 |
| 36 | Lighter on the front | 20 |
| 37 | Rear lighter | 20/30 |
| 38 | additional cooling fan | 20 |
| 39 | Door control unit front right | 7.5 |
| 40 | brake servo | 15 |
| 41 | Rear right door control unit | 7.5 |
| 42 | Additional heating/additional heating | 20 |
| 43 | Headlight cleaning device | 30 |
| 44 | heater fan |
Fuse No. 36A with a current rating of 20A is responsible for the front cigarette lighter.
Trunk fuse box
On the left side

Deciphering
| NO. | consumer | amplifier |
| 1 | absent | |
| 2 | absent | |
| 3 | absent | |
| 4 | absent | |
| 5 | DSP amplifier | 30 |
| 6 | navigation | 5 |
| 7 | TV tuner | 10 |
| 8 | absent | |
| 9 | Communication block | 5 |
| 10 | Telephone speaker in the luggage rack | 15 |
| 11 | Departure | 20 |
| 12 | Autonomous radio heating | 5 |
on the right side

Designation
| NO. | Deciphering | Denomination, A |
| 1 | Right fuel pump (diesel) | 20 |
| 2 | Left fuel pump (petrol/diesel) | 20 |
| 3 | trailer socket | 15 |
| 4 | absent | |
| 5 | Intelligent Rear Power Module (left light) | 20 |
| 6 | Intelligent Rear Power Module (Right Light) | 10 |
| 7 | Intelligent Rear Power Module (Trunk Closing Assist) | 20 |
| 8 | electromechanical parking brake, left engine | 30 |
| 9 | electromechanical parking brake, right engine | 30 |
| 10 | Trailer control unit (left light) | 15 |
| 11 | Trailer control unit (right light) | 15 |
| 12 | Trailer control unit | 10 |
Diagrams and descriptions are for informational purposes only. For actual fuse locations, refer to your vehicle’s owner’s manual.