Smart Forfour (W454; 2004 – 2006) – fuse box diagram
Year of production: 2004, 2005, 2006
Fuse box
| No. | Fused function | A |
| 1 | Interior illumination Upper control panel control unit Left SAM control unit Rain sensor/light sensor Instrument cluster Combination switch Central gateway control unit |
10 |
| 2 | Left SAM control unit | 10 |
| 3 | Left standing lamp and taillamp | 7,5 |
| 4 | Right parking light and taillamp | 7,5 |
| 5 | Front wiper | 20 |
| 6 | Vacant | — |
| 7 | Heated outside mirror | 7,5 |
| 8 | Right high beam | 10 |
| 9 | Left high beam | 10 |
| 10 | Horn | 10 |
| 11 | Fuel pump | 15 |
| 12 | ENGINE 122.9, 134.9, 135.9: Motor electronics control unit Motor relay Throttle valve relay |
20 |
| 13 | Trailer hitch socket (13-pin) circuit 30 | 15 |
| 14 | Glass sliding roof | 20 |
| 15 | Rear window wiper motor | 15 |
| 16 | Cigarette lighter | 15 |
| 17 | Rear fog lamp | 7,5 |
| 18 | Outside mirror adjustment | 7,5 |
| 19 | ENGINE 639.9: EDG control unit |
15 |
| 20 | ENGINE 639.9: EDG control unit Fuel pump relay 2 Motor relay |
7,5 |
| 21 | Right low beam | 10 |
| 22 | Left low beam, headlamp range adjustment | 10 |
| 23 | Front fog lamp (up to model year 04) | 15 |
| Front fog lamp (as of model year 05) | 10 | |
| 24 | Diagnostic socket, central locking (up to model year 04) | 15 |
| 25 | Trailer hitch socket (13-pin) circuit 15 | 15 |
| 26 | Turn signal lights | 15 |
| 27 | Radio | 15 |
| 28 | Anti-theft alarm system | 10 |
| 29 | Manual transmission | 20 |
| 30 | Diagnostic socket, central locking (as of model year 05) | 15 |
| 31 | Brake lights Stop lamp switch (4-pin) |
15 |
| 32 | AAC [KLA] control and operating unit | 7,5 |
| 33 | ESP control unit Steering assist control unit Restraint systems control unit |
7,5 |
| 34 | ENGINE 122.9, 134.9, 135.9: Ignition coils |
10 |
| 35 | EDG control unit Fuel pump relay 1 |
7,5 |
| 36 | Reversing lights | 7,5 |
| 37 | Rear window heater | 30 |
| 38 | Heated seats | 30 |
| 39 | ENGINE 639.9: EDG control unit |
30 |
| 40 | Heater blower | 40 |
| 41 | Ignition/starter switch | 40 |
| 42 | Power windows Headlamp cleaning system pump |
40 |
| 43 | Engine coolant fan motor | 40 |
| 44 | Electronic selector lever module control unit (with transmission 717.474, 717.475) | 40 |
| Relay | ||
| A | Power window relay | |
| B | Horn relay | |
| C | Fuel pump 2 relay | |
| D | Rear fog lamps relay | |
| E | Starter relay | |
| F | Gasoline/diesel engine relay | |
| G | Preexcitation alternator | |
| H | Fan stage 1 relay | |
| I | Fog lamp relay | |
| J | Heater relay | |
| K | Fuel pump 1 relay | |
| L | Transmission relay | |
| M | Trailer hitch bridge | |
| N | Free (backup relay) | |
| O | Fan stage 2 relay | |
| P | Headlamp cleaning system relay | |
| Q | Rear window defroster relay | |
| R | Heated seats bridge | |
| S | Low beam relay | |
| T | High beam relay | |
| U | Throttle valve relay (only with engine 134.910, 135.930/950) | |
WARNING: Terminal and harness assignments for individual connectors will vary depending on vehicle equipment level, model, and market.