2011-2018 Mercedes-Benz B-Class (W246, W242) Fuse Box Diagram
Fuse box in the engine compartment
- Open the hood.
- Use a dry cloth to remove any moisture from the fuse box.
- To open: unclip hood release cable (4) from bracket (3).
- Open retaining clamps (2).
- Fold cover (1) up in the direction of the arrow and remove it.
- To close: check whether the seal is seated correctly in cover (1).
- Insert cover (1) at the back into openings (5) on the fuse box.
- Slide hood release cable (4) to the side and hold if necessary.
- Fold down cover (1).
- Clip hood release cable (4) into bracket (3).
| No. | A | Description |
|---|---|---|
| 201 | 5 | Alarm siren |
| 202 | 20 | Stationary heater control unit |
| 5 | Electric Drive (W242): Park pawl control unit circuit 87 relay | |
| 203 | 15 | LED headlamp: Right front lamp unit |
| 5 | Electric Drive (W242): Powertrain control unit | |
| 204 | 25 | Electronic Stability Program control unit |
| 205 | 15 | Left fanfare horn
Right fanfare horn |
| 206 | 5 | OM651: CDI control unit
OM607: Powertrain control unit Electric Drive (W242): Brake booster vacuum pump relay Circuit relay87M |
| 207 | 5 | Diesel: Circuit relay87M
Electric Drive (W242): High-voltage battery cooling shutoff valve Park pawl control unit |
| 208 | 7.5 | M133, OM607: Circuit 87 relay |
| 5 | Electric Drive (W242): Fan motor | |
| 209 | 15 | LED headlamp: Left front lamp unit |
| - | Electric Drive (W242): Spare | |
| 210 | 5 | Heated windshield relay |
| 5 | 03.11.2014→ (except Canada): Starter front-end relay | |
| 211 | 7.5 | Natural Gas Drive (W242): CNG control unit |
| 15 | Electric Drive (W242): Heater circuit circulation pump | |
| 212 | 15 | M133, M270: Connector sleeve, circuit 87M3
OM651: Vent line heater element Coolant thermostat heating element Exhaust gas recirculation cooler bypass switchover valve OM607 (Emissions standard EU5): Oxygen sensor upstream of catalytic converter Boost pressure positioner OM607 (Emissions standard EU6): Oxygen sensor upstream of catalytic converter OM607: CDI control unit Electric Drive (W242): Electric drive and charger coolant pump |
| 213 | 15 | M133, M270, OM651: Connector sleeve, circuit 87 M2e
OM607 (Emissions standard EU5): Camshaft Hall sensor CDI control unit Quantity control valve OM607 (Emissions standard EU6): Oxygen sensor downstream of catalytic converter CDI control unit Electric Drive (W242): Battery cooling system coolant pump 1 |
| 214 | 10 | M133, M270, OM651: Connector sleeve, circuit 87 M4e |
| 15 | Electric Drive (W242): Battery cooling system coolant pump 2 | |
| 215 | 20 | Gasoline:
Cylinder 1 ignition coil Cylinder 2 ignition coil Cylinder 3 ignition coil Cylinder 4 ignition coil OM651: Quantity control valve OM607: CDI control unit Boost pressure positioner Quantity control valve |
| 5 | Electric Drive (W242):
Thermal management control unit Gateway powertrain control unit Electric Drive (W242) 03.11.2014→: High-voltage power distributor |
|
| 216 | 5 | Gasoline: ME-SFI control unit
OM607: Powertrain control unit |
| 217 | 25 | Valid with transmission 724: Dual clutch transmission fully integrated transmission control unit |
| 218 | 5 | Electronic Stability Program control unit |
| 219 | 5 | Electric Drive (W242): Park pawl control unit |
| 220 | 10 | Transmission cooling coolant circulation pump |
| 221 | 40 | Electric Drive (W242): Vacuum pump |
| 222 | 7.5 | Electric Drive (W242): Electrical refrigerant compressor |
| 223 | - | Spare |
| 224 | 7.5 | DISTRONIC electric controller unit
COLLISION PREVENTION ASSIST controller unit |
| 225 | 5 | Electric Drive (W242): Powertrain control unit |
| 226 | 5 | Natural Gas Drive (W242): CNG control unit
Electric Drive (W242): Charger control unit Power electronics control unit |
| 227 | 5 | Electric Drive (W242): Power electronics control unit |
| 228 | 5 | Electric Drive (W242): Electric vehicle sound generator |
| 229 | 5 | Left front lamp unit |
| 230 | 5 | Electronic Stability Program control unit |
| 231 | 5 | Right front lamp unit |
| 232 | 15 | Headlamp control unit |
| 233 | - | Spare |
| 234 | 5 | OM607: Powertrain control unit |
| 10 | Electric Drive (W242): High-voltage power distributor | |
| 235 | 7.5 | OM607:
Fan motor Radiator shutters actuator |
| 7.5 | M133:
Charge air cooler circulation pump Charge air cooler circulation pump |
|
| 236 | 40 | SAM control unit |
| 237 | 40 | Electronic Stability Program control unit |
| 238 | 50 | Heated windshield |
| 239 | 30 | Wiper speed 1/2 relay |
| 240A | 25 | Starter circuit 50 relay |
| 7.5 | Electric Drive (W242): Powertrain control unit | |
| 240B | 25 | Circuit 15 relay (not latched) |
| 241 | 7.5 | Electric Drive (W242): High-voltage PTC heater |
| Relay | ||
| J | Fanfare horn | |
| K | Wiper speed 1/2 | |
| L | Windshield wiper ON/OFF | |
| M | Starter circuit 50 | |
| Electric Drive (W242): Circuit 87C | ||
| N | Circuit 87M | |
| O | ECO start/stop: Transmission cooling coolant circulation pump | |
| Electric Drive (W242): Park pawl control unit circuit 87 | ||
| P | Backup (F58kP) | |
| Q | Circuit 15 (not latched)
Electric Drive (W242): Brake booster vacuum pump supply |
|
| R | Circuit 15 | |
| S | Circuit 87 | |
| T | Heated windshield | |
Gasoline:
- M270 - 1.6L (B160, B 180 BlueEFFICIENCY, B180, B200)
- M270 - 2.0L (B200 Natural Gas Drive, B220 4MATIC, B250, B250 4MATIC)
Diesel:
- OM607 - 1.5L (B160 CDI, B180 CDI & B180 CDI BlueEFFICIENCY)
- OM651 - 1.8L (B180 CDI, B200 CDI)
- OM651 - 2.2L (B200 CDI, B200 CDI 4MATIC)
- OM651 - 2.2L (B220 CDI & B220 CDI 4MATIC)
B250e - Electric Drive (W242)
| If you manipulate or bridge a faulty fuse or if you replace it with a fuse with a higher amperage, the electric cables could be overloaded. This could result in a fire. There is a risk of an accident and injury.
Always replace faulty fuses with the specified new fuses having the correct amperage. |
Fuse box in the front-passenger foot-well
- To open: open the front-passenger door.
- Remove the floormat.
- Fold out perforated floor covering (1) in the direction of the arrow.
- To release cover (3), press retaining clamp (2).
- Fold out cover (3) in the direction of the arrow to the catch.
- Remove cover (3) forwards.
Fuse allocation chart (4) is located on the lower right-hand side of cover (3). - To close: insert cover (3) on the left-hand side of the fuse box into the retainer. Cover (3) engages in the retainers.
- Fold down cover (3) until clamps (2) lock audibly.
- Fold back perforated floor covering (1).
- Install the floormats.
| No. | A | Description |
|---|---|---|
| 21 | 150 | Diesel: PTC heater booster |
| 22 | 200 | Additional battery relay for ECO start/stop function |
| 23 | 30 | Left front door control unit |
| 24 | 30 | Right front door control unit |
| 25 | 30 | SAM control unit |
| 26 | 10 | ECO start/stop additional battery connector sleeve |
| 27 | 30 | Engine compartment fuse and relay module |
| 28 | 5 | Vehicle interior sound generator control unit
Electric Drive (W242): Thermal management control unit |
| 29 | 15 | →02.11.2014: Trailer socket |
| 15 | 03.11.2014→: Trailer recognition control unit | |
| 30 | 5 | Trailer recognition control unit |
| 31 | 5 | 4MATIC: All-wheel drive control unit |
| 32 | 5 | Steering column tube module control unit |
| 33 | 5 | Audio/COMAND control panel |
| 34 | 7,5 | ACC control and operating unit |
| 35 | 40 | Rear window heater |
| 36 | 7,5 | Driver seat control unit
Driver seat lumbar support adjustment control unit |
| 37 | 7,5 | Audio/COMAND display |
| 38 | 7,5 | Supplemental Restraint System control unit |
| 39 | 10 | Overhead control panel control unit |
| 40 | 15 | OM651 (Emissions standard EU6): Powertrain control unit |
| 5 | Electric Drive (W242): Powertrain control unit | |
| 41 | 30 | Panoramic sliding sunroof control module |
| 42 | 5 | Radio (Audio 5 USB, Audio 20 CD, Audio 20 CD with CD changer)
COMAND controller unit |
| 25 | Radio (Radio 20, Audio 20 USB) | |
| 43 | 5 | Parking system control unit |
| 44 | 40 | Left front reversible emergency tensioning retractor |
| 45 | 40 | Right front reversible emergency tensioning retractor |
| 46 | 7,5 | Front passenger seat control unit
Front passenger seat lumbar support adjustment control unit |
| 47 | 7,5 | Navigation module |
| 25 | Adaptive damping system control unit | |
| 48 | - | Spare |
| 49 | 7,5 | Control unit for Drive Kit for iPhone® |
| 5 | COMAND fan motor | |
| 50 | - | Spare |
| 51 | - | Spare |
| 52 | 30 | Electric Drive (W242): Park pawl actuator motor |
| 53 | - | Spare |
| 54 | - | Spare |
| 55 | 5 | Telematics services communications module
KEYLESS-GO control unit |
| 56 | 10 | Steering column tube module control unit |
| 57 | 30 | Lane Keeping Assist: Special-purpose vehicle multifunction control unit |
| 7.5 | Special vehicle: Special-purpose vehicle multifunction control unit | |
| 5 | Electric Drive (W242): Park pawl actuator motor circuit 87 relay (F34kG) | |
| 58 | 30 | Emergency vehicle fuse box |
| 59 | 30 | Front passenger seat control uni |
| 60 | 30 | Driver seat control unit |
| 61 | 40 | Sound system amplifier control unit |
| 62 | 20 | Valid for transmission 711: Electric steering lock control unit |
| 63 | 25 | Fuel system control unit |
| 5 | Electric Drive (W242): Gateway powertrain control unit | |
| 64 | 1 | Electronic Toll Collection control unit
Dedicated Short-Range Communications control unit |
| 65 | 5 | Glove compartment lamp |
| 66 | 15 | Emergency vehicle fuse box |
| 5 | Special-purpose vehicle interface | |
| 67 | - | Spare |
| 68 | - | Spare |
| 69 | - | Spare |
| 70 | 25 | Rear center console socket |
| 71 | 25 | Luggage compartment socket |
| 72 | 25 | Front cigarette lighter with ashtray illumination
Vehicle interior power outlet |
| 73 | 30 | Electric parking brake control unit |
| 74 | 30 | Electric parking brake control unit |
| 75 | 20 | Trailer recognition control unit |
| 5 | Electric Drive (W242): Battery management system control unit | |
| 76 | 25 | Trailer recognition control unit |
| 5 | Electric Drive (W242): Park pawl control unit | |
| 77 | 25 | Trailer recognition control unit |
| 78 | 40 | Emergency vehicle fuse box |
| 79 | 40 | SAM control unit |
| 80 | 40 | SAM control unit |
| 81 | 40 | Blower regulator |
| 82 | 10 | Overhead control panel control unit |
| 83 | 7,5 | Electronic ignition lock control unit |
| 84 | 5 | Upper control panel control unit |
| 85 | 5 | ATA [EDW]/tow-away protection/interior protection control unit |
| 86 | 5 | FM, AM and CL [ZV] antenna amplifier
01.06.2016→: Cellular telephone system antenna amplifier / compensator |
| 87 | 10 | Diagnostic connector |
| 88 | 10 | Instrument cluster |
| 89 | 5 | Exterior lights switch |
| 90 | 5 | Left rear bumper intelligent radar sensor
Intelligent radar sensor for right rear bumper |
| 91 | 5 | Pedal operation monitor switch
Footwell illumination switch Electric Drive (W242): Battery management system control unit |
| 92 | 5 | Fuel system control unit
Electric Drive (W242): Gateway powertrain control unit |
| 93 | 5 | Electric parking brake control unit |
| 94 | 7,5 | Supplemental Restraint System control unit |
| 95 | 7,5 | Front passenger seat occupied recognition and ACSR
Weight sensing system (WSS) control unit |
| 96 | 15 | Tailgate wiper motor |
| 97 | 5 | Mobile phone electrical connector |
| 98 | 5 | SAM control unit |
| 99 | 5 | Tire pressure monitor control unit |
| 100 | 5 | M133: DIRECT SELECT INTERFACE |
| 101 | 10 | 4MATIC: All-wheel drive control unit |
| 102 | 5 | Stationary heater radio remote control receiver
Electric Drive (W242): Powertrain control unit AMG (01.09.2015→): Transmission mode control unit 01.06.2016→: Antenna changeover switch for telephone and stationary heater |
| 103 | 5 | Emergency call system control unit
Telematics services communications module HERMES control unit |
| 104 | 5 | Media interface control unit
Multimedia connection unit |
| 105 | 5 | Digital Audio Broadcasting control unit
Satellite digital audio radio (SDAR) control unit |
| 7,5 | Tuner unit | |
| 106 | 5 | Multifunction camera |
| 107 | 5 | Digital TV tuner |
| 108 | 5 | →31.05.2016: Reversing camera |
| 7,5 | 01.06.2016→: Reversing camera | |
| 109 | 20 | Charging socket electrical connector |
| 110 | 30 | Radio
COMAND controller unit Engine sound control unit |
| Relay | ||
| A | Circuit 15 | |
| B | Rear window wiper | |
| C | Circuit 15R2 | |
| D | Heated rear window | |
| E | Circuit 15R1 | |
| F | Circuit 30g | |
| G | Electric Drive (W242): Park pawl actuator motor circuit 87 | |
Front electrical prefuse box
| No. | A | Description |
|---|---|---|
| 1 | 300 | Alternator |
| 400 | Electric Drive (W242): DC/DC converter control unit | |
| 2 | 200 | Vehicle interior fuse box |
| 250 | Diesel: Vehicle interior fuse box | |
| 3 | 100 | Electrical power steering control unit |
| 4 | 40 | SAM control unit |
| 5 | 80 | Fan motor |
| 6 | 70 | OM607: Fuel preheating control unit |
| 7 | 125 | OM607 (Emissions standard EU5): DPF regeneration heater booster control unit |
| 8 | 100 | OM607, OM651: Glow output stage |
| Relay | ||
| k1 | Decoupling | |