2011-2018 Mercedes-Benz B-Class (W246, W242) Fuse Box Diagram

12.04.2017 (US:04.12.17), Category: Mercedes / B-Class

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 engine compartment

2011-2018 Mercedes-Benz B-Class (W246, W242) Fuse Box Diagram
  • 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.
Fused function
A
201 Alarm siren 5
202 Stationary heater control unit 20
Electric Drive (W242): Park pawl control unit circuit 87 relay 5
203 LED headlamp: Right front lamp unit 15
Electric Drive (W242): Powertrain control unit 5
204 Electronic Stability Program control unit 25
205 Left fanfare horn
Right fanfare horn
15
206 Valid for engine 651: CDI control unit
Valid for engine 607: Powertrain control unit
Electric Drive (W242):
  
Brake booster vacuum pump relay
   Circuit relay87M
5
207 Valid for diesel engine: Circuit relay87M
Electric Drive (W242):
   High-voltage battery cooling shutoff valve
   Park pawl control unit
5
208 Valid for engine 133, 607: Circuit 87 relay 7.5
Electric Drive (W242): Fan motor 5
209 LED headlamp: Left front lamp unit 15
Electric Drive (W242): Spare -
210 Heated windshield relay 5
as of 03.11.2014 except (Canada version): Starter front-end relay 5
211 Natural Gas Drive (W242): CNG control unit 7.5
Electric Drive (W242): Heater circuit circulation pump 15
212 Valid for engine 133, 270: Connector sleeve, circuit 87M3
Valid for engine 651:
   Vent line heater element
   Coolant thermostat heating element
   Exhaust gas recirculation cooler bypass switchover valve
Valid for engine 607 (Emissions standard EU5):
   Oxygen sensor upstream of catalytic converter
   Boost pressure positioner
Valid for engine 607 (Emissions standard EU6): Oxygen sensor upstream of catalytic converter
Valid for engine 607: CDI control unit
Electric Drive (W242): Electric drive and charger coolant pump
15
213 Valid for engine 133, 270, 651: Connector sleeve, circuit 87 M2e
Valid for engine 607 (Emissions standard EU5):
   Camshaft Hall sensor
   CDI control unit
   Quantity control valve
Valid for engine 607 (Emissions standard EU6):
   Oxygen sensor downstream of catalytic converter
   CDI control unit
Electric Drive (W242): Battery cooling system coolant pump 1
15
214 Valid for engine 133, 270, 651: Connector sleeve, circuit 87 M4e 10
Electric Drive (W242): Battery cooling system coolant pump 2 15
215 Valid for gasoline engine:
   Cylinder 1 ignition coil
   Cylinder 2 ignition coil
   Cylinder 3 ignition coil
   Cylinder 4 ignition coil
Valid for engine 651: Quantity control valve
Valid for engine 607:
   CDI control unit
   Boost pressure positioner
   Quantity control valve
20
Electric Drive (W242):
   Thermal management control unit
   Gateway powertrain control unit
Electric Drive (W242) as of 03.11.2014: High-voltage power distributor
5
216 Valid for gasoline engine: ME-SFI control unit
Valid for engine 607: Powertrain control unit
5
217 Valid with transmission 724: Dual clutch transmission fully integrated transmission control unit 25
218 Electronic Stability Program control unit 5
219 Electric Drive (W242): Park pawl control unit 5
220 Transmission cooling coolant circulation pump 10
221 Electric Drive (W242): Vacuum pump 40
222 Electric Drive (W242): Electrical refrigerant compressor 7.5
223 Spare -
224 DISTRONIC electric controller unit
COLLISION PREVENTION ASSIST controller unit
7.5
225 Electric Drive (W242): Powertrain control unit 5
226 Natural Gas Drive (W242): CNG control unit
Electric Drive (W242):
   Charger control unit
   Power electronics control unit
5
227 Electric Drive (W242): Power electronics control unit 5
228 Electric Drive (W242): Electric vehicle sound generator 5
229 Left front lamp unit 5
230 Electronic Stability Program control unit 5
231 Right front lamp unit 5
232 Headlamp control unit 15
233 Spare -
234 Valid for engine 607: Powertrain control unit 5
Electric Drive (W242): High-voltage power distributor 10
235 Valid for engine 607:
   Fan motor
   Radiator shutters actuator
7.5
Valid for engine 133:
  
Charge air cooler circulation pump
   Charge air cooler circulation pump
7.5
236 SAM control unit 40
237 Electronic Stability Program control unit 40
238 Heated windshield 50
239 Wiper speed 1/2 relay 30
240A Starter circuit 50 relay 25
Electric Drive (W242): Powertrain control unit 7.5
240B Circuit 15 relay (not latched) 25
241 Electric Drive (W242): High-voltage PTC heater 7.5
Relay
J Fanfare horn relay
K Wiper speed 1/2 relay
L Windshield wiper ON/OFF relay
M Starter circuit 50 relay
Electric Drive (W242): Circuit 87C relay  
N Circuit relay87M
O ECO start/stop: Transmission cooling coolant circulation pump relay
Electric Drive (W242): Park pawl control unit circuit 87 relay
P Backup relay (F58kP)
Q Circuit 15 relay (not latched)
Electric Drive (W242): Brake booster vacuum pump supply relay (F58kQ)
R Circuit 15 relay
S Circuit 87 relay
T Heated windshield relay

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.
Fused function
A
21 Valid for diesel engine: PTC heater booster 150
22 Additional battery relay for ECO start/stop function 200
23 Left front door control unit 30
24 Right front door control unit 30
25 SAM control unit 30
26 ECO start/stop additional battery connector sleeve 10
27 Engine compartment fuse and relay module 30
28 Vehicle interior sound generator control unit
Electric Drive (W242): Thermal management control unit
5
29 up to 02.11.2014: Trailer socket
as of 03.11.2014: Trailer recognition control unit
15
30 Trailer recognition control unit 5
31 4MATIC: All-wheel drive control unit 5
32 Steering column tube module control unit 5
33 Audio/COMAND control panel 5
34 ACC control and operating unit 7,5
35 Rear window heater 40
36 Driver seat control unit
Driver seat lumbar support adjustment control unit
7,5
37 Audio/COMAND display 7,5
38 Supplemental Restraint System control unit 7,5
39 Overhead control panel control unit 10
40 Valid for engine 651 (Emissions standard EU6): Powertrain control unit 15
Electric Drive (W242): Powertrain control unit 5
41 Panoramic sliding sunroof control module 30
42 Radio (Audio 5 USB, Audio 20 CD, Audio 20 CD with CD changer)
COMAND controller unit
5
Radio (Radio 20, Audio 20 USB) 25
43 Parking system control unit 5
44 Left front reversible emergency tensioning retractor 40
45 Right front reversible emergency tensioning retractor 40
46 Front passenger seat control unit
Front passenger seat lumbar support adjustment control unit
7,5
47 Navigation module 7,5
Adaptive damping system control unit 25
48 Spare -
49 Control unit for Drive Kit for iPhone® 7,5
COMAND fan motor 5
50 Spare -
51 Spare -
52 Electric Drive (W242): Park pawl actuator motor 30
53 Spare -
54 Spare -
55 Telematics services communications module
KEYLESS-GO control unit
5
56 Steering column tube module control unit 10
57 Lane Keeping Assist: Special-purpose vehicle multifunction control unit 30
Special vehicle: Special-purpose vehicle multifunction control unit 7.5
Electric Drive (W242): Park pawl actuator motor circuit 87 relay (F34kG) 5
58 Emergency vehicle fuse box 30
59 Front passenger seat control uni 30
60 Driver seat control unit 30
61 Sound system amplifier control unit 40
62 Valid for transmission 711: Electric steering lock control unit 20
63 Fuel system control unit 25
Electric Drive (W242): Gateway powertrain control unit 5
64 Electronic Toll Collection control unit
Dedicated Short-Range Communications control unit
1
65 Glove compartment lamp 5
66 Emergency vehicle fuse box 15
Special-purpose vehicle interface 5
67 Spare -
68 Spare -
69 Spare -
70 Rear center console socket 25
71 Luggage compartment socket 25
72 Front cigarette lighter with ashtray illumination
Vehicle interior power outlet 
25
73 Electric parking brake control unit 30
74 Electric parking brake control unit 30
75 Trailer recognition control unit 20
Electric Drive (W242): Battery management system control unit (N82/2) 5
76 Trailer recognition control unit (N28/1) 25
Electric Drive (W242): Park pawl control unit 5
77 Trailer recognition control unit 25
78 Emergency vehicle fuse box 40
79 SAM control unit 40
80 SAM control unit 40
81 Blower regulator 40
82 Overhead control panel control unit 10
83 Electronic ignition lock control unit 7,5
84 Upper control panel control unit 5
85 ATA [EDW]/tow-away protection/interior protection control unit 5
86 FM, AM and CL [ZV] antenna amplifier
as of 01.06.2016: Cellular telephone system antenna amplifier / compensator
5
87 Diagnostic connector 10
88 Instrument cluster 10
89 Exterior lights switch 5
90 Left rear bumper intelligent radar sensor
Intelligent radar sensor for right rear bumper
5
91 Pedal operation monitor switch
Footwell illumination switch
Electric Drive (W242): Battery management system control unit
5
92 Fuel system control unit
Electric Drive (W242): Gateway powertrain control unit
5
93 Electric parking brake control unit 5
94 Supplemental Restraint System control unit 7,5
95 Front passenger seat occupied recognition and ACSR
Weight sensing system (WSS) control unit
7,5
96 Tailgate wiper motor 15
97 Mobile phone electrical connector 5
98 SAM control unit 5
99 Tire pressure monitor control unit 5
100 Valid for engine 133: DIRECT SELECT INTERFACE 5
101 4MATIC: All-wheel drive control unit 10
102 Stationary heater radio remote control receiver
Electric Drive (W242): Powertrain control unit
Valid for AMG vehicles as of 01.09.2015: Transmission mode control unit
as of 01.06.2016: Antenna changeover switch for telephone and stationary heater
5
103 Emergency call system control unit
Telematics services communications module
HERMES control unit
5
104 Media interface control unit
Multimedia connection unit
5
105 Digital Audio Broadcasting control unit
Satellite digital audio radio (SDAR) control unit
5
Tuner unit 7,5
106 Multifunction camera 5
107 Digital TV tuner 5
108 up to 31.05.2016: Reversing camera 5
as of 01.06.2016: Reversing camera 7,5
109 Charging socket electrical connector 20
110 Radio
COMAND controller unit
Engine sound control unit
30
Relay
A Circuit 15 relay
B Rear window wiper relay
C Circuit 15R2 relay
D Heated rear window relay
E Circuit 15R1 relay
F Circuit 30g relay
G Electric Drive (W242): Park pawl actuator motor circuit 87 relay


Front electrical prefuse box

No.
Fused function
A
1 Alternator 300
Electric Drive (W242): DC/DC converter control unit 400
2 Vehicle interior fuse box 200
Valid for diesel engine: Vehicle interior fuse box 250
3 Electrical power steering control unit 100
4 SAM control unit 40
5 Fan motor 80
6 Valid for engine 607: Fuel preheating control unit 70
7 Valid for engine 607 (Emissions standard EU5): DPF regeneration heater booster control unit 125
8 Valid for engine 607, 651: Glow output stage 100
Relay
F32k1 Decoupling relay

Fuse Box Layout Mercedes-Benz B-Class (W246) B160, B180, B200, B220, B250 and B-Class Electric Drive (W242) (2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018)