Mercedes W176 represents the third generation of the Mercedes-Benz A-class model range, which was produced in 2013, 2014, 2015, 2016, 2017, 2018 and was designated as A180, A200, A250, A180, A200, A220. During this time, the model underwent restyling. In this publication, we will show a description of the fuses and relays of the Mercedes W176 with block diagrams, photo examples of their execution and location. We will highlight the fuse responsible for the cigarette lighter.
Block in the cabin
In the passenger compartment, the main block with fuses and relays is located under the panel, on the passenger side under a protective cover.
Description
| 21 | 150A Additional electric heater (vehicles with diesel engine) |
| 22 | 200A Additional battery relay for ECO Start-Stop function |
| 23 | 30A Front Left Door Control Unit |
| 24 | 30A Front Right Door Control Unit |
| 25 | 30A SAM Control Unit |
| 26 | 10A Termination cable joint for additional battery for “ECO Start-Stop” function |
| 27 | 30A Engine Compartment Fuse and Relay Module |
| 28 | 5A Interior Sound Generator Control Unit |
| 29 | 15A Trailer Socket (until 02.11.2014) |
| Trailer presence recognition control unit (since 03.11.2014) | |
| 30 | 5A Trailer presence recognition control unit |
| 31 | 5A All-wheel drive control unit |
| 32 | 5A Signals from the electronic steering column module control unit |
| 33 | 5A Control panel for audio module/COMAND system |
| 34 | 7.5A Climate control system control panel |
| 35 | 40A Rear window heating |
| 36 | 7.5A Driver Seat Control Unit |
| Driver’s seat lumbar support adjustment control unit | |
| 37 | 7.5A Display audio module/COMAND system |
| 38 | 7.5A Supplemental Restraint System Control Unit |
| 39 | 10A Ceiling Control Panel |
| 40 | 15A Transmission Control Unit (Engine 651) |
| 41 | 30A Panoramic Sliding Sunroof Control Module |
| 42 | 5A Audio Module |
| COMAND control module | |
| 25A Audio Module | |
| 43 | 5A Parking assistance control unit |
| 44 | 40A Front Left Reversible Seat Belt Tensioner |
| 45 | 40A Front Right Reversible Seat Belt Tensioner |
| 46 | 7.5A Front Passenger Seat Control Unit |
| Lumbar support adjustment control unit for front passenger seat | |
| 47 | 7.5A Navigation module |
| 25A Adaptive Damping Control Unit | |
| 48 | Reserve |
| 49 | 7.5A Drive Kit Control Unit for iPhone |
| 5A COMAND Fan Motor | |
| 50 | 5A Chamber Lid Control Unit |
| 51 | Reserve |
| 52 | 30A Parking Lock Actuator Signal |
| 53 | Reserve |
| 54 | Reserve |
| 55 | 5A Telecommunication Services Communication Module |
| KEYLESS-GO control unit | |
| 56 | 10A Signals from the electronic steering column module control unit |
| 57 | 30A Multifunctional Control Unit for Special Vehicle |
| 7.5A Multifunctional Control Unit for Special Vehicle | |
| 5A Terminal 87 Relay Parking Lock Actuator | |
| 58 | 30A Special Purpose Vehicle Fuse Box |
| 59 | 30A Front Passenger Seat Control Module |
| 60 | 30A Driver Seat Control Unit |
| 61 | 40A Speaker Amplifier Control Unit |
| 62 | 20A Electric steering lock control unit (gearbox 711) |
| 63 | 25A Fuel Pump Control Unit |
| 64 | Control unit “Electronic Toll Collection” |
| DSRC Toll Data Transfer Control Unit | |
| 65 | 5A Glove box light |
| 66 | 15A Special Purpose Vehicle Fuse Box |
| 5A Special Vehicle Interface | |
| 67 | Reserve |
| 68 | Reserve |
| 69 | Reserve |
| 70 | 25A Rear Center Console Socket |
| 71 | 25A Socket in the Trunk |
| 72 | 25A Cigarette Lighter with Front Ashtray Light |
| Socket in the cabin | |
| 73 | 30A Electric Parking Brake Control Unit |
| 74 | 30A Electric Parking Brake Control Unit |
| 75 | 20A Trailer Recognition Control Unit |
| 76 | 25A Trailer Recognition Control Unit |
| 77 | 25A Trailer Recognition Control Unit |
| 78 | 40A Boot lid control unit/tailgate drive control unit |
| Special Purpose Vehicle Fuse Box | |
| 79 | 40A SAM Control Unit |
| 80 | 40A SAM Control Unit |
| 81 | 40A Fan Controller |
| 82 | 10A Ceiling Control Panel |
| 83 | 7.5A Electronic ignition switch control unit |
| 84 | 5A Upper Control Panel |
| 85 | 5A EDW/tow away protection/interior monitoring control unit |
| 86 | 5A FM, AM and ZV Antenna Amplifier |
| Antenna amplifier/compensator for mobile communications (since 01.06.2016) | |
| 87 | 10A Diagnostic socket |
| 88 | 10A Instrument cluster |
| 89 | 5A Outdoor Lighting Switch |
| 90 | 5A Intelligent radar sensor in rear bumper left |
| Intelligent radar sensor in the rear bumper on the right | |
| 91 | 5A Pedal Pressure Control Sensor |
| Footwell Light Switch | |
| 92 | 5A Fuel Pump Control Unit |
| 93 | 5A Electric Parking Brake Control Unit |
| 94 | 7.5A Supplemental Restraint System Control Unit |
| 95 | 7.5A Front Passenger Seat Occupancy Recognition and AKSE |
| Weight Sensing System Control Unit | |
| 96 | 15A Tailgate Windscreen Wiper Motor |
| 97 | 5A Mobile Phone Electrical Plug Connector |
| 98 | 5A SAM Control Unit |
| 99 | 5A Tire pressure monitoring system control unit |
| 100 | 5A DIRECT SELECT Interface (engine 133) |
| 101 | 10A All-wheel drive control unit |
| 102 | 5A Receiver for remote control of independent heater |
| Drive mode control unit (AMG, from 01.09.2015) | |
| Antenna switch for telephone and independent heater (from 01.06.2016) | |
| 103 | 5A Emergency Call Control Unit |
| Communication module of telecommunication services | |
| HERMES control unit | |
| 104 | 5A Multimedia Interface Control Unit |
| Multimedia Device Connection Module | |
| 105 | 5A Digital Audio Broadcasting Control Unit |
| Satellite Digital Audio Radio (SDAR) Control Unit | |
| 7.5A Tuner Module | |
| 106 | 5A Multifunctional Camera |
| 107 | 5A Digital TV Tuner |
| 108 | 5A Rear view camera |
| 109 | 20A Electrical Plug Socket Connection for Cargo |
| 110 | 30A Audio module |
| COMAND control module | |
| Motorsound control unit | |
| Relay | |
| A | Relay terminal 15 |
| B | Rear Window Wiper Relay |
| C | Relay terminals 15R2 |
| D | Rear window heating relay |
| AND | Relay terminals 15R1 |
| F | Relay terminals 30g |
| G | Not used |
Fuses 70, 71 and 72 are responsible for the cigarette lighters.
Blocks under the hood
Under the hood, on the left side of the engine compartment, there may be 2 fuse boxes.
Fuse and relay box
To access the unit, you need to remove the protective cover.
Designation
| 201 | 5A Alarm Siren |
| 202 | 20A Autonomous Heater Control Unit |
| 203 | 15A Front right headlight |
| 204 | 25A Electronic stability control unit |
| 205 | 15A Left horn |
| Sound signal right | |
| 206 | 5A CDI Control Unit (Engine 651) |
| 207 | 5A Electrical Circuit Relay Terminal 87M (Diesel) |
| 208 | 7.5A Relay Terminal 87 (Motors: 133, 607) |
| 209 | 15A Front left headlight |
| 210 | 5A Heated Front Window Relay |
| Pre-starter relay | |
| 211 | 7.5A Reserve |
| 212 | 15A Cable Lug Electrical Circuit Terminal 87M3 (133, 270 Motors) |
| 15A Heating element of ventilation pipe (engine 651) | |
| Heating element of the cooling system thermostat (engine 651) | |
| EGR Cooler Bypass Valve (Engine 651) | |
| 15A Lambda probe before catalytic converter (engine 607) | |
| Boost Pressure Regulating Servo (607 Engine) | |
| CDI control unit (engine 607) | |
| 213 | 15A Terminal 87 Cable End Sleeve (133, 270, 651 Motors) |
| 15A Camshaft Hall Sensor (Engine 607) | |
| CDI control unit (engine 607) | |
| Metering valve (engine 607) | |
| Lambda probe after catalytic converter (engine 607) | |
| 214 | 10A Terminal 87 Cable End Sleeve (133, 270, 651 Motors) |
| 215 | 20A Ignition coil cylinder 1 (petrol engines) |
| Ignition coil cylinder 2 (petrol engines) | |
| Ignition coil cylinder 3 (petrol engines) | |
| Ignition coil cylinder 4 (petrol engines) | |
| 20A Metering Valve (Motor 651) | |
| 20A CDI Control Unit (Engine 607) | |
| Boost Pressure Regulating Servo (607 Engine) | |
| Metering valve (engine 607) | |
| 216 | 5A ME control unit (petrol engines) |
| Transmission Control Unit (Engine 607) | |
| 217 | 25A Control unit for fully integrated dual clutch transmission control system (724 transmission) |
| 218 | 5A Electronic stability control unit |
| 219 | 5A Reserve |
| 220 | 10A Circulation pump for gearbox oil cooling system (gearbox 724) |
| 221 | 40A Reserve |
| 222 | 7.5A Reserve |
| 223 | Reserve |
| 224 | 7.5A Electrical control module DISTRONIC |
| COLLISION PREVENTION ASSIST control module | |
| 225 | 5A Reserve |
| 226 | 5A Reserve |
| 227 | 5A Reserve |
| 228 | 5A Reserve |
| 229 | 5A Front left headlight |
| 230 | 5A Electronic stability control unit |
| 231 | 5A Front right headlight |
| 232 | 15A Headlight Control Unit |
| 233 | Reserve |
| 234 | 5A Transmission Control Module (Engine 607) |
| 235 | 7.5A Fan Motor (Motor 607) |
| Radiator shutter actuator (engine 607) | |
| Charge air cooler circulation pump (engine 133) | |
| 236 | 40A SAM Control Unit |
| 237 | 40A Electronic stability control unit |
| 238 | 50A Heated Windshield |
| 239 | 30A Windscreen Wiper Mode Relay 1/2 |
| 240A | 25A Starter Terminal 50 Relay |
| 240B | 25A Terminal 15 Relay (No Support) |
| 241 | 7.5A Reserve |
| Relay | |
| J | Sound signal relay |
| K | Windscreen wiper speed relay 1/2 |
| L | Windscreen wiper relay on/off |
| M | Starter terminal 50 relay |
| N | Relay electric circuit terminals 87M |
| THE | Relay of the coolant circulation pump of the gearbox oil cooling system |
| P | Reserve relay |
| Q | Terminal 15 relay (unprotected) |
| R | Relay terminal 15 |
| S | Relay terminal 87 |
| T | Heated Windshield Relay |
Fuse box
The high power fuse box is located next to the fuse and relay box.
Scheme
Purpose
| F1 | 300A Generator |
| F2 | 200A Passenger Compartment Fuse Box (Petrol Engines) |
| 250A Passenger Compartment Fuse Box (Diesel Engines) | |
| F3 | 100A Electric Power Steering Control Unit |
| F4 | 40A SAM Control Unit |
| F5 | 80A Fan Motor |
| F6 | 70A Fuel Heating Control Unit (Engine 607) |
| F7 | 125A DPF Regeneration Auxiliary Heater Control Unit (Engine 607) |
| F8 | 100A Glow Plug Output Module (Engines: 651, 607) |
| Relay | |
| F32k1 | Isolation relay (F32k1) |