Mercedes-Benz A-Class Fuse Box Locations and Diagrams (2012-2018)

The third-generation Mercedes-Benz A-Class (W176), produced from 2012 to 2018, marked a major shift in design and philosophy for the A-Class lineup. Departing from the tall compact MPV form of its predecessors, the W176 embraced a sleek, sporty hatchback silhouette aimed at younger, performance-oriented drivers. With turbocharged engine options, advanced safety features, and premium interior appointments, the W176 firmly positioned itself as a dynamic contender in the luxury compact segment.

In this article, you will find fuse box diagrams for the Mercedes-Benz A-Class, covering models A160, A180, A200, A220, and A250 for the years 2012, 2013, 2014, 2015, 2016, 2017, and 2018. These diagrams provide vital details about the fuse layout, helping owners, DIYers, and mechanics identify the correct fuse or relay to inspect or replace.

What’s Included:

Fuse Box Diagrams – Accurate illustrations showing the layout and function of each fuse, relay, and circuit breaker.
Fuse Panel Locations – Detailed instructions on where to find the fuse panels inside the vehicle, including the passenger compartment and engine bay.
Fuse Assignments – A complete reference of what each fuse and relay controls to support electrical troubleshooting and system maintenance.

Whether you’re addressing an electrical malfunction, replacing a blown fuse, or simply getting familiar with your A-Class’s internal systems, this guide is an essential tool.

Ensure your Mercedes-Benz A-Class (2012–2018) stays road-ready with this comprehensive fuse box, relay diagram, and fuse panel location resource.

The cigar lighter (power outlet) fuses in the Mercedes-Benz A-Class are located in the Passenger Compartment Fuse Box:
- Fuse №70: Rear Center Console Socket
- Fuse №71: Luggage Compartment Socket
- Fuse №72: Front Cigarette Lighter / Interior Power Outlet

What’s Included

Passenger Compartment Fuse Box

Fuse box location

The fuse box is located under the floor near the passenger seat (remove the floormats and covering).

The location of the fuses in the passenger compartment: Mercedes-Benz A-Class (2013-2018)

Fuse box diagram

Assignment of the fuses and relay in the passenger compartment

№	Fused function	Amp
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	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
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
42	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 iPhone® cradle control unit	7,5
47	Adaptive damping system control unit	25
48	Not used	–
49	Control unit for Drive Kit for iPhone®	7,5
49	COMAND fan motor	5
50	Camera cover control unit	5
51	Not used	–
52	Not used	–
53	Not used	–
54	Not used	–
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
57	Special vehicle: Special-purpose vehicle multifunction control unit	7,5
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
64	Electronic Toll Collection control unit Dedicated Short-Range Communications control unit	1
65	Glove compartment lamp	5
66	Emergency vehicle fuse box	15
67	Not used	–
68	Not used	–
69	Not used	–
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
76	Trailer recognition control unit	25
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	5
92	Fuel system 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 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
105	Tuner unit	7,5
106	Multifunction camera	5
107	Digital TV tuner	5
108	up to 31.05.2016: Reversing camera	5
108	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	Not used

Front Electrical Prefuse Box

Front Electrical Pre-fuse Box

№	Fused function	Amp
1	Alternator	300
2	Vehicle interior fuse box	200(petrol) 250(diesel)
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
F32kl	Decoupling relay

Engine Compartment Fuse Box

Fuse box location

The location of the fuses in the engine compartment: Mercedes-Benz A-Class (2013-2018)

Fuse box diagram

Assignment of the fuses and relay in the engine compartment

№	Fused function	Amp
201	Alarm siren	5
202	Stationary heater control unit	20
203	LED headlamp: Right front lamp unit	15
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	5
207	Valid for diesel engine: Circuit relay 87M	5
208	Valid for engine 133, 607: Circuit 87 relay	7.5
209	LED headlamp: Left front lamp unit	15
210	Heated windshield relay as of 01.09.2015: Starter front-end relay	5
211	Not used	–
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	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	15
214	Valid for engine 133, 270, 651: Connector sleeve, circuit 87 M4e	10
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
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	Not used	–
220	Transmission cooling coolant circulation pump	10
221	Not used	–
222	Not used	–
223	Not used	–
224	DISTRONIC electric controller unit COLLISION PREVENTION ASSIST controller unit	7.5
225	Not used	–
226	Not used	–
227	Not used	–
228	Not used	–
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	Not used	–
234	Valid for engine 607: Powertrain control unit	5
235	Valid for engine 607: Fan motor Radiator shutters actuator	7.5
235	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
240B	Circuit 15 relay (not latched)	25
241	Not used	7.5

Relay
J	Fanfare horn relay
K	Wiper speed 1/2 relay
L	Windshield wiper ON/OFF relay
M	Starter circuit 50 relay
N	Circuit relay 87M
O	ECO start/stop: Transmission cooling coolant circulation pump relay
P	Backup relay (F58kP)
Q	Circuit 15 relay (not latched)
R	Circuit 15 relay
S	Circuit 87 relay
T	Heated windshield relay