Mercedes-Benz C-Class Fuse Box Locations and Diagrams (2008-2014)
The third-generation Mercedes-Benz C-Class (W204), produced from 2008 to 2014, brought a refined blend of performance, luxury, and safety. This generation includes models such as the C180, C200, C220, C250, C300, C350, and the high-performance C63 AMG.
In this article, you will find fuse box diagrams for Mercedes-Benz C-Class W204 model years 2008, 2009, 2010, 2011, 2012, 2013, and 2014. This guide also provides detailed fuse layouts, helping you understand the assignment of each fuse and relay across the vehicle’s systems.
Fuse Box Locations – Instructions on where to find each fuse panel inside the car (commonly in the engine bay, footwell, or trunk).
Fuse Assignments – Full listings of what each fuse and relay controls, including:
Lighting
Climate control
Multimedia
Power windows and seats
Engine and transmission electronics
Whether you’re replacing a blown fuse or diagnosing an electrical issue, this reference ensures you have the accurate information needed to maintain or repair the electrical system of your Mercedes-Benz C-Class (W204) efficiently.
The cigar lighter (power outlet) fuses in the Mercedes-Benz C-Class are:
Engine Compartment Fuse Box:
Fuse №9: Glove Compartment Power Outlet
Luggage Compartment Fuse Box:
Fuse №71: Front Cigarette Lighter / Front Interior Power Outlet
Fuse №72: Cargo Area Connector Box – 115V Power Outlet
The fuse box is located in the engine compartment (left-side), under the cover.
Fuse box diagram
Assignment of the fuses and relay in the engine compartment
№
Fused function
Amp
1
Electronic Stability Program control unit
25
2
Left front door control unit
30
3
Valid up to 31.3.10: Right front door control unit Valid as of 1.4.10 with model 204.0/2/9: Right rear door control unit
30
4
up to 31.8.08: Fuel pump control unit Valid for engine 156 up to 31.8.08: Left fuel pump control unit Right fuel pump control unit Valid for engine 642, engine 651: Fuel filter condensation sensor with heating element Valid for engine 651 up to 31.5.10, engine 646: Control unit for fuel filter condensation sensor with heating element
7.5
4
Valid for diesel engine as of 1.9.08: Fuel filter condensation sensor with heating element Valid for engine 276 (USA, South Korea): Activated charcoal canister shutoff valve Valid for model 204.0/2/3 as of 1.3.11, 204.9 as of 1.6.12: Headlamp control unit
20
5
Rear SAM control unit with fuse and relay module Valid as of 1.6.10 Exterior lights switch Valid for engine 156 Black Series as of 1.7.11: Rear axle differential coolant circuit relay
7.5
6
Valid for diesel engine: ME-SFI [ME] control unit Valid for gasoline engine: CDI control unit
10
7
Starter
20
8
Supplemental restraint system control unit
7.5
9
Glove compartment power outlet
15
10
Wiper motor
30
11
Audio/COMAND display Audio/COMAND control panel Holder for navigation module
7.5
12
Automatic air conditioning control and operating unit Upper control panel control unit
7.5
13
Steering column module control unit Multifunction camera
7.5
14
Electronic Stability Program control unit
7.5
14
Headlamp control unit
20
15
Supplemental restraint system control unit
7.5
16
Diagnostic connector (up to 31.5.09) Mobile phone electrical connector Valid for transmission 722: Electronic selector lever module control unit
5
16
ECO start/stop function: Electric transmission oil pump
20
17
Panoramic sliding roof control module Overhead control panel control unit
30
18
Valid up to 30.11.09: Exterior lights switch Valid for model 204.0/2 as of 1.3.11, model 204.3: Upper control panel control unit Valid for model 204.0/2 up to 28.2.11, model 204.9: Instrument panel climate control LIN positive line connector sleeve Vehicle interior and harness for taillamp electrical connector
7.5
19
Electric steering lock control unit Electronic ignition lock control unit
Combustion engine fan motor and air conditioning with integrated control Electrical connector for interior harness and engine wiring harness
15
23
Electrical connector for interior harness and engine wiring harness Valid for diesel engine: Rear SAM control unit with fuse and relay module CDI control unit Terminal 87 connector sleeve Valid for engine 271: Terminal 87 M1e connector sleeve Valid for engine 272: Circuit 87 M1i connector sleeve
20
24
Electrical connector for interior harness and engine wiring harness Interior and engine wiring harness electrical connector Valid for engine 642: Radiator shutters actuator Valid for engine 272: Terminal 87 M1e connector sleeve Valid for diesel engine: Terminal 87 connector sleeve Valid for engine 646: CDI control unit
15
25
Valid for engine 156, 271, 272, 274, 276: ME-SFI [ME] control unit Valid for diesel engine: Oxygen sensor upstream of catalytic converter Valid as of 1.6.10 for model 204.3 with engine 651 Sport Edition: Exhaust system sound generator control unit
15
26
Radio Radio with auto pilot system COMAND controller unit
20
27
Electric steering lock control unit Electronic ignition lock control unit Valid for diesel engine: CDI control unit Valid for gasoline engine: ME-SFI [ME] control unit
7.5
28
Instrument cluster
7.5
29
Right front lamp unit
10
30
Left front lamp unit Valid for engine 642: Electrical connector for interior harness and engine wiring harness
10
31A
Left fanfare horn Right fanfare horn
15
31B
Left fanfare horn Right fanfare horn
15
32
Valid for engine 156, 271, 272, 276: Electric air pump
40
32
Valid for engine 156: Oil cooler fan motor
20
33
Valid for transmission 722.6: Electronic transmission-control control unit Valid for transmission 722.9: Fully integrated transmission control controller unit
10
34
Valid for engine 271, 272 as of 1.9.08: Fuel pump control unit Valid for engine 156 as of 1.9.08: Left fuel pump control unit, Right fuel pump control unit
7.5
35
Valid as of 1.3.11: Electronic Stability Program control unit
5
36
Valid as of 1.3.11: DISTRONIC electric controller unit Valid for model 204.902/982/984: Electrohydraulic power steering
7.5
Relay
J
Circuit 15 relay
K
Terminal 15R relay
L
Backup relay
M
Circuit 50 starter relay
O
Engine circuit 87 relay
O
Fanfare horn relay
P
Valid for engine 156, 272, 276: Secondary air injection relay
It is located in the luggage compartment (on the right-side), behind the cover.
Fuse box diagram
Version 1
Version 2
Assignment of the fuses and relay in the trunk
№
Fused function
Amp
37
as of 2008: Driver seat NECK-PRO head restraint solenoid, Front passenger seat NECK-PRO head restraint solenoid
5
37
up to 2008: Driver seat NECK-PRO head restraint solenoid, Front passenger seat NECK-PRO head restraint solenoid
7.5
38
Tailgate wiper motor
15
39
Valid for model 204.0/2/9 except vehicles for Great Britain up to 31.5.09: Left rear door control unit
30
40
Spare
–
41
Valid for model 204.0/2/9 up to 31.3.10: Right rear door control unit Valid as of 1.4.10 Right front door control unit
30
42
Valid for gasoline engine or engine 642 as of 1.12.09 or engine 651 as of 1.6.09: Fuel pump control unit
25
42
Valid for engine 646 or engine 642 up to 30.11.09 or engine 651 up to 31.5.09: Fuel pump Valid for gasoline engine (up to 2009): Fuel pump control unit
20
43
Valid as of 1.6.09 with automatic air conditioning: Rear blower motor
5
44
Switch group, right front seat setting Front passenger seat partially electric seat adjustment switch
30
45
Left front seat adjustment switch group Driver seat partially electric seat adjustment switch
30
46
Antenna amplifier for rear window FM antenna Alarm siren Interior protection and tow-away protection control unit Rear window antenna amplifier 1 TV 1 antenna amplifier and DAB Band III DAB band III antenna TV 2 antenna amplifier and KEYLESS-GO KEYLESS-GO antenna amplifier
7.5
47
Spare
–
48
Spare
–
49
Rear window heater
40
50
Right front reversible emergency tensioning retractor
50
51
Left front reversible emergency tensioning retractor (A76)
50
52
Spare
–
53
as of 2008: Trailer recognition control unit
15
53
up to 2008: Trailer recognition control unit
30
54
up to 31.5.09: Trailer recognition control unit Valid for model 204.075/077/275/277: Driver seat lumbar support and side bolster adjustment switch group Front passenger seat lumbar support and side bolster adjustment switch group Front passenger seat AMG valve block Driver seat AMG valve block
7.5
54
as of 1.6.09: Trailer recognition control unit
15
55
Valid as of 1.6.09: AdBlue
5
56
Trailer recognition control unit Trailer socket
15
56
Valid for model 204.077/277/377 up to 31.5.09: Driver seat lumbar support and side bolster adjustment switch group Front passenger seat lumbar support and side bolster adjustment switch group Front passenger seat AMG valve block Driver’s seat AMG valve block
5
57
Trailer recognition control unit
20
58
as of 2008: Trailer recognition control unit
20
58
up to 2008: Trailer recognition control unit
30
59
as of 2008: Parking system control unit Left front bumper DISTRONIC (DTR) sensor Right front bumper DISTRONIC (DTR) sensor Intelligent radar sensor for left rear bumper Intelligent radar sensor for right rear bumper
5
59
up to 2008: PARKTRONIC control unit Radar sensors control unit
7.5
60
Multicontour seat pneumatic pump
7.5
61
Liftgate-control control unit
40
62
Driver seat control unit
30
63
Front passenger seat control unit
30
64
DC/AC converter control unit
25
65
Adaptive damping system control unit Steering column tube module control unit
15
66
Spare
–
67
as of 2008: Sound system amplifier control unit
30
67
up to 2008: Sound system amplifier control unit
40
68
Spare
.
69
Rear bass speaker amplifier
20
70
Tire pressure monitor control unit
5
71
Front cigarette lighter with ashtray illumination Front vehicle interior power outlet
15
72
Cargo area connector box 115 V power outlet
15
73
Diagnostic connector (as of 1.6.09) Stationary heater radio remote control receiver Valid for engine 156 as of 1.7.11: Transmission mode control unit
7.5
74
KEYLESS-GO control unit
15
75
Stationary heater unit
20
76
Vehicle interior power outlet
15
77
Weight Sensing System (WSS) control unit
7.5
78
Left front seat ventilation blower regulator Right front seat ventilation blower regulator
7.5
79
Parking system control unit
5
80
Video and radar sensor system control unit Parking system control unit
7.5
81
Media interface control unit
5
82
Cellular telephone system compensator UMTS TV tuner control unit (up to 31.5.09; Japan) Digital TV tuner (up to 31.5.09; Japan)
5
83
Electronic Toll Collection control unit (Japan) Emergency call system control unit Reversing camera Left rear display Right rear display
7.5
84
Satellite digital audio radio (SDAR) control unit SDAR/high definition tuner control unit Digital Audio Broadcasting control unit Backup camera power supply module Backup camera control unit 360° camera control unit
7.5
85
TV tuner control unit (up to 31.5.09; Japan) Digital TV tuner (as of 1.6.09; Japan)
7.5
86
DVD player
7.5
87
Emergency call system control unit
7.5
88
Valid as of 1.6.09 Spare
–
89
Valid as of 1.6.09: Trailer recognition control unit Valid as of 1.6.09 with engine 156: Oil cooler fan motor relay
20
90
Valid as of 1.6.09 AdBlue® fuse block, AdBlue supply relay
40
91
DC/AC converter control unit
25
91
ECO start/stop: Transmission oil auxiliary pump control unit Valid for engine 642: Vent line heater element
