The Mercedes-Benz W176 is a compact car manufactured by German automaker Daimler AG. Marketed as the third generation of the A-Class, it is distinguished from its predecessors by a significantly lower, sportier body profile. This manual provides a detailed breakdown of the fuse and relay diagrams for the Mercedes-Benz A-Class W176 (third generation; models A180, A200, A220, and A250) for model years 2013 through 2018.
Below you will find the locations, component descriptions, and layout diagrams for the power distribution boxes. Fuses for the cigarette lighter and fuel pump are highlighted in bold.
Engine Compartment
Two main fuse boxes protect the vehicle's electrical circuits.
Power Fuse Box (1)
Located adjacent to the main engine compartment fuse box.
General view.
| Diagram | ||
|---|---|---|
|
||
| No. | Description | Amperage |
| F32k1 | Decoupling relay (F32k1) | - |
| F1 | Alternator | 300 A |
| F2 | Interior fuse box (gasoline engines) | 200 A |
| Interior fuse box (diesel engines) | 250 A | |
| F3 | Electric Power Steering (EPS) control module | 100 A |
| F4 | SAM control module | 40 A |
| F5 | Radiator fan motor | 80 A |
| F6 | Fuel heater control module (OM607 engine) | 70 A |
| F7 | DPF regeneration auxiliary heater control module (OM607 engine) | 125 A |
| F8 | Glow plug control module (OM607, OM651 engines) | 100 A |
Main Fuse Box (2)
General view.
| Diagram | ||
|---|---|---|
|
||
| No. | Description | Amperage |
| J | Horn relay | - |
| K | Windshield wiper stage 1/2 relay | - |
| L | Windshield wiper ON/OFF relay | - |
| M | Starter terminal 50 relay | - |
| N | Terminal 87M circuit relay | - |
| O | Transmission oil cooling circulation pump relay | - |
| P | Reserve relay | - |
| Q | Terminal 15 relay (unfused) | - |
| R | Terminal 15 relay | - |
| S | Terminal 87 relay | - |
| T | Heated windshield relay | - |
| 201 | Alarm siren | 5 A |
| 202 | Auxiliary heater control module | 20 A |
| 203 | Right headlight assembly | 15 A |
| 204 | Electronic Stability Program (ESP) control module | 25 A |
| 205 | Left and right horns | 15 A |
| 206 | CDI control module (OM651 engine) | 5 A |
| 207 | Terminal 87M circuit relay (diesel engines) | 5 A |
| 208 | Terminal 87 relay (M133, OM607 engines) | 7.5 A |
| 209 | Left headlight assembly | 15 A |
| 210 | Starter pre-relay, heated windshield relay | 5 A |
| 211 | Unassigned | 7.5 A |
| 212 | Crankcase ventilation line heater, cooling system thermostat heater, EGR cooler bypass valve (OM651 engine); Terminal 87M3 connector block (M133, M270 engines); Upstream oxygen (lambda) sensor, boost pressure actuator, CDI control module (OM607 engine) | 15 A |
| 213 | Terminal 87 connector block (M133, M270, OM651 engines) / CDI control module, fuel metering valve, camshaft Hall sensor, downstream oxygen (lambda) sensor (OM607 engine) | 15 A |
| 214 | Terminal 87 connector block (M133, M270, OM651 engines) | 10 A |
| 215 | Ignition coils 1–4 (gasoline engines) / Fuel metering valve (OM651 engine) / CDI control module, boost pressure actuator, fuel metering valve (OM607 engine) | 20 A |
| 216 | ME engine control module (gasoline engines) / Transmission control module (OM607 engine) | 5 A |
| 217 | Fully integrated dual-clutch transmission control module (724.0 transmission) | 25 A |
| 218 | Electronic Stability Program (ESP) control module | 5 A |
| 219 | Unassigned | 5 A |
| 220 | Transmission oil cooling circulation pump (724.0 transmission) | 10 A |
| 221 | Unassigned | 40 A |
| 222 | Unassigned | 7.5 A |
| 223 | Unassigned | - |
| 224 | COLLISION PREVENTION ASSIST control module, DISTRONIC control module | 7.5 A |
| 225 - 228 | Reserve | 5 A |
| 229 | Left headlight assembly | 5 A |
| 230 | Electronic Stability Program (ESP) control module | 5 A |
| 231 | Right headlight assembly | 5 A |
| 232 | Headlight control module | 15 A |
| 233 | Reserve | |
| 234 | Transmission control module (OM607 engine) | 5 A |
| 235 | Radiator fan motor and radiator shutter actuator (OM607 engine) / Intercooler coolant circulation pump (M133 engine) | 7.5 A |
| 236 | SAM control module | 40 A |
| 237 | Electronic Stability Program (ESP) control module | 40 A |
| 238 | Heated windshield | 50 A |
| 239 | Windshield wiper stage 1/2 relay | 30 A |
| 240A | Starter terminal 50 relay | 25 A |
| 240B | Terminal 15 relay (unfused) | 25 A |
| 241 | Reserve | 7.5 A |
Passenger Compartment
The interior fuse box is located in the front passenger footwell behind the floor carpeting.
To access the fuses, pull back the floor matting/trim panel and remove the fuse box cover.
General view.
| Diagram | ||
|---|---|---|
|
||
| No. | Description | Amperage |
| A | Terminal 15 relay | - |
| B | Rear window wiper relay | - |
| C | Terminal 15R2 relay | - |
| D | Heated rear window relay | - |
| E | Terminal 15R1 relay | - |
| F | Terminal 30g relay | - |
| G | Unassigned | - |
| 21 | Auxiliary electric heater (diesel models) | 150 A |
| 22 | ECO Start-Stop auxiliary battery relay | 200 A |
| 23 | Front left door control module | 30 A |
| 24 | Front right door control module | 30 A |
| 25 | SAM control module | 30 A |
| 26 | ECO Start-Stop auxiliary battery connector block | 10 A |
| 27 | Engine compartment fuse and relay module | 30 A |
| 28 | Interior sound generator control module | 5 A |
| 29 | Trailer socket (up to 11/02/2014) or trailer recognition control module (from 11/03/2014) | 15 A |
| 30 | Trailer recognition control module | 5 A |
| 31 | All-wheel drive (4MATIC) control module | 5 A |
| 32 | Steering column module signal feed | 5 A |
| 33 | Audio unit / COMAND control panel | 5 A |
| 34 | Climate control panel | 7.5 A |
| 35 | Heated rear window | 40 A |
| 36 | Driver seat lumbar support control module, driver seat control module | 7.5 A |
| 37 | Audio unit / COMAND display | 7.5 A |
| 38 | Supplemental Restraint System (SRS) control module | 7.5 A |
| 39 | Overhead control panel | 10 A |
| 40 | Transmission control module (OM651 engine) | 15 A |
| 41 | Panoramic sunroof control module | 30 A |
| 42 | Audio unit / COMAND control module (5 A) or Audio unit (25 A) | 5 A / 25 A |
| 43 | PARKTRONIC / Parking Assist control module | 5 A |
| 44 | Left front reversible emergency tensioning retractor (ETR) | 40 A |
| 45 | Right front reversible emergency tensioning retractor (ETR) | 40 A |
| 46 | Front passenger seat lumbar support control module, front passenger seat control module | 7.5 A |
| 47 | Navigation module (7.5 A) / Adaptive Damping System (ADS) control module (25 A) | 7.5 A / 25 A |
| 48 | Reserve | - |
| 49 | Drive Kit Plus for iPhone control module (7.5 A) / COMAND cooling fan motor (5 A) | 7.5 A / 5 A |
| 50 | Backup camera cover actuator control module | 5 A |
| 51 | Reserve | - |
| 52 | Parking lock actuator motor signal | 30 A |
| 53 | Reserve | |
| 54 | Reserve | |
| 55 | KEYLESS-GO control module, telematics services communication module | 5 A |
| 56 | Steering column module signal feed | 10 A |
| 57 | Special-purpose vehicle multifunction control module (30 A); | 30 A / 7.5 A / 5 A |
| Special-purpose vehicle multifunction control module (7.5 A); | ||
| Terminal 87 parking lock actuator motor relay (5 A) | ||
| 58 | Special-purpose vehicle fuse box | 30 A |
| 59 | Front passenger seat control module | 30 A |
| 60 | Driver seat control module | 30 A |
| 61 | Audio amplifier control module | 40 A |
| 62 | Electric steering lock (ESL) control module (711 transmission) | 20 A |
| 63 | Fuel pump control module (Mercedes W176 fuel pump fuse) | 25 A |
| 64 | DSRC electronic toll collection control module | |
| 65 | Glove box light | 5 A |
| 66 | Special-purpose vehicle fuse box (15 A) / Special-purpose vehicle interface (5 A) | 15 A / 5 A |
| 67 | Reserve | - |
| 68 | Reserve | - |
| 69 | Reserve | - |
| 70 | Rear center console power socket / cigarette lighter (Mercedes A-Class W176) | 25 A |
| 71 | Luggage compartment auxiliary power socket | 25 A |
| 72 | Front cigarette lighter with illuminated ashtray, interior power socket | 25 A |
| 73 | Electric Parking Brake (EPB) control module | 30 A |
| 74 | 30 A | |
| 75 | Trailer recognition control module | 20 A |
| 76 | 25 A | |
| 77 | 25 A | |
| 78 | Special-purpose vehicle fuse box; trunk lid / tailgate control module | 40 A |
| 79 | SAM control module | 40 A |
| 80 | SAM control module | 40 A |
| 81 | Blower fan controller | 40 A |
| 82 | Overhead control panel | 10 A |
| 83 | Electronic Ignition Switch (EIS) control module | 7.5 A |
| 84 | Upper control panel (UCP) | 5 A |
| 85 | Anti-theft alarm (EDW) / tow-away protection / interior motion sensor control module | 5 A |
| 86 | Antenna amplifier / mobile phone compensator (from 06/01/2016); AM/FM/central locking antenna amplifier | 5 A |
| 87 | Diagnostic connector (OBD-II) | 10 A |
| 88 | Instrument cluster | 10 A |
| 89 | Exterior light switch | 5 A |
| 90 | Left and right rear bumper radar sensors | 5 A |
| 91 | Footwell light switch, pedal position sensor | 5 A |
| 92 | Fuel pump control module | 5 A |
| 93 | Electric Parking Brake (EPB) control module | 5 A |
| 94 | Supplemental Restraint System (SRS) control module | 7.5 A |
| 95 | Weight Sensing System (WSS) control module, front passenger seat occupancy recognition | 7.5 A |
| 96 | Rear window wiper motor | 15 A |
| 97 | Mobile phone pre-wiring connector | 5 A |
| 98 | SAM control module | 5 A |
| 99 | Tire Pressure Monitoring System (TPMS) control module | 5 A |
| 100 | DIRECT SELECT interface module (M133 engine) | 5 A |
| 101 | All-wheel drive (4MATIC) control module | 10 A |
| 102 | Auxiliary heater RF receiver, AMG DYNAMIC SELECT control module (from 09/01/2015), or telephone/auxiliary heater antenna switch (from 06/01/2016) | 5 A |
| 103 | Emergency call (eCall) system control module, telematics communication module, HERMES control module | 5 A |
| 104 | Media interface connection module / control module | 5 A |
| 105 | Satellite Digital Audio Radio (SDAR) & Digital Radio (DAB) control module (5 A) / Tuner module (7.5 A) | 5 A / 7.5 A |
| 106 | Multifunction camera | 5 A |
| 107 | Digital TV tuner | 5 A |
| 108 | Rearview camera | 5 A |
| 109 | Cargo area auxiliary power outlet | 20 A |
| 110 | Audio unit, COMAND control module, Active Sound control module | 30 A |