Fuses and relays Mercedes GLA (X156, 2013 - 2020)

This material discusses in detail the fuse diagrams of a Mercedes GLA car (first generation / factory index X156):  2013, 2014, 2015, 2016, 2017, 2018, 2019 and 2020  with the designations GLA 180, GLA 200, GLA 220, GLA 250, GLA 45 AMG.

Fuses numbered 70, 71 and 72 in the cabin block are responsible for protecting the electrical circuits of the cigarette lighters.

In the underhood compartment

The mounting block is located on the left side of the engine compartment. 

It consists of two sections.

Diagram
No.	Description	Amps
Section 1
F1	Generator 300A type 242.890: 400A DC voltage converter control unit	300 / 400
F2	Fuse box in passenger compartment (gasoline)	200
	Interior Fuse Block (Diesel)	250
F3	Power steering control unit	100
F4	SAM control unit	40
F5	Fan motor	80
F6	engine 607: fuel heating control unit	70
F7	engine 607: DPF regeneration auxiliary heater control unit	125
F8	engines: 651, 607: Glow plug output stage module	100
F32k1	Decoupling relay	-
Section 2
J	Horn relay
K	Wiper speed relay 1/2
L	Wiper relay on/off
M	Relay terminal 87C (type 242.890) Starter terminal 50 relay
N	Relay terminal 87M
O	Relay terminal 87 parking lock control unit (type 242.890) Transmission oil coolant circulation pump relay
P	spare relay
Q	Power supply relay for brake booster vacuum pump (type 242.890) Terminal 15 relay (unprotected)
R	Relay terminal 15
S	Relay terminal 87
T	Heated windshield relay
201	alarm siren	5
202	Auxiliary heater control unit	20
	type 242.890: Relay terminal 87 parking lock control unit	5
203	Front right headlight	15
	Transmission control unit (type 242.890)	5
204	Control unit for electronic motion stabilization system	25
205	Horn (left and right)	15
206	engine 651: CDI control unit Type 242.890: Transmission control unit, El. circuit terminal 87M, brake booster vacuum pump relay	5
207	Type 242.890: HV battery cooling shut-off valve, Parking lock control unit diesel: Relay el. circuit terminals 87M	5
208	Terminal 87 relay (motors: 133, 607)	7.5
	Fan motor (type 242.890)	5
209	Front left headlight	15
	Reserve (type 242.890)	-
210	Heated front window relay	5
	type 176 from 09/01/2015, type 246 from 11/03/2014: Starter pre-relay	-
211	CNG control unit (type 242.848)	7.5
	Heating circuit circulation pump (type 242.890)	15
212	motors 133, 270: cable lug electr. circuit terminals 87M3 ( )	15
	Engine 651: EGR cooler bypass changeover valve, Ventilation pipe heater, Coolant thermostat heater
	607 engine: CDI control unit, Boost pressure control servo, Lambda probe before catalytic converter
	Type 242.890: Electric drive and charger coolant pump
213	type 242.890: Coolant pump 1 for battery cooling, motors 133, 270, 651: Terminal 87 cable termination engine 607: Camshaft Hall sensor, Lambda probe after catalytic converter, CDI control unit, Metering valve	15
214	motors 133, 270, 651: Terminal 87 cable termination	10
	Type 242.890: Coolant pump 2 for battery cooling	15
215	petrol engines: Ignition coils of cylinders 1/2/3/4; engine 607: CDI control unit, Metering valve, Boost pressure control servo; engine 651: Dosing valve	20
	Type 242.890: Transmission Gateway Control Unit, Thermal Management Unit	5
	type 242.890 as of 11/03/2014: High-voltage power distributor	5
216	engine 607: Transmission control unit / petrol engines: ME control unit	5
217	724 gearbox: Control unit for fully integrated dual clutch gearbox control system	25
218	Control unit for electronic motion stabilization system	5
219	type 242.890: Parking lock control unit	5
220	724 gearbox: Circulation pump of the gearbox oil cooling system	10
221	type 242.890: Vacuum pump	40
222	type 242.890: Electric air conditioner compressor	7.5
223	Spare
224	COLLISION PREVENTION ASSIST control module, DISTRONIC electrical control module	7.5
225	Type 242.890: Transmission control unit	5
226	type 242.848: CNG control unit Type 242.890: Power Electronics Control Unit and Charger Control Unit	5
227	Type 242.890: Power electronics control module	5
228	Type 242.890: Electric vehicle sound generator	5
229	Front left headlight	5
230	Control unit for electronic motion stabilization system	5
231	Front right headlight	5
232	headlight control module	15
233	Spare	-
234	607 engine: Transmission control module	5
	type 242.890: High voltage power distributor	10
235	Engine 607: Fan Motor, Radiator Shutter Actuator engine 133: charge air cooler circulation pump	7.5
236	SAM management module	40
237	Electronic motion stabilization control module	40
238	Heated windshield	50
239	Wiper Mode Relay 1/2	30
240A	Starter terminal 50 relay	25
	Type 242.890: Transmission control unit	7.5
240B	without support: Relay terminal 15	25
241	type 242.890: High voltage electric heater system	7.5

In the cabin

The fuse box is located behind the floor trim at the foot of the front passenger.

Access example.

Diagram
No.	Relay
A	terminal 15
B	rear window wiper
C	terminal 15R2
D	rear window heating
E	terminal 15R1
F	terminal 30g
G	terminal 87 parking lock control motor (type 242.890)
No.	Fuses	Amps
21	Additional electric heater (models with a diesel engine)	150
22	Additional battery relay for ECO Start-Stop function	200
23	front left door control	30
24	front right door control	30
25	SAM control unit	30
26	Additional battery cable termination for “ECO Start-Stop” function	10
27	fuses and relays in the engine compartment	30
28	Thermal management unit (type 242.890) Cabin sound generator control unit (type 176 with engine 651)	5
29	Trailer detection control unit (from 03.11.2014) / Trailer socket (up to 02.11.2014)	15
30	Trailer detection control module	5
31	AWD control module	5
32	Signals from the steering control unit	5
33	Audio / COMAND system control panel	5
34	Climate Control Panel	7.5
35	type 117, 176, 242, 246: Heated rear window	40
	type 156: Heated rear window	30
36	Lumbar support adjustment control unit for driver's seat, Driver's seat control unit	7.5
37	Audio module / COMAND system display	7.5
38	Control unit for passenger restraint system (Supplemental Restraint System)	7.5
39	Ceiling Control Panel	10
40	engine 651: Transmission control module	15
	Type 242.890: Transmission control module	5
41	Panoramic sliding sunroof control module	30
42	Audio module, COMAND control module	5
	Audio module	25
43	Parking assistance control unit	5
44	Reversible front left seat belt pretensioner	40
45	Reversible front right seat belt pretensioner	40
46	Lumbar support adjustment control unit for front passenger seat, Front passenger seat control unit	7.5
47	Holder Control Unit for iPhone, Navigation Module	7.5
	Control unit for adaptive damping system	25
48	Not used	-
49	Drive Kit Control Unit for iPhone	7.5
	COMAND fan motor	5
50	Camera Cover Control Unit	5
51	Not used	-
52	Parking lock actuator signal	30
53	Not used	-
54	Not used	-
55	KEYLESS-GO System, Telecommunication Services Communication Module	5
56	Signals from the steering column electronic module control unit	10
57	Multifunction control unit for special vehicle	30
		7.5
	Terminal 87 relay Park lock actuator	5
58	Special Vehicle Fuse Box	30
59	Front passenger seat control unit	30
60	Driver's seat control unit	30
61	Audio system amplifier	40
62	Electric steering lock control unit (gearbox 711)	20
63	Fuel pump control unit	25
	Transmission interface control unit (type 242.890)	5
64	Control unit “Electronic Toll Collection”	-
	DSRC Toll Communication Control Unit	-
65	Glove box light	5
66	Special Vehicle Fuse Box	15
	Special vehicle interface	5
67	Not used	-
68	Not used	-
69	Not used	-
70	Cigarette lighter socket in the center console in the rear	25
71	Cigarette lighter socket in trunk	25
72	Front cigarette lighter socket with ashtray illumination	25
73	Electric parking brake control unit	30
74		30
75	Trailer detection control unit	20
	Battery management system control unit (type 242.890)	5
76	Trailer recognition control module	25
	Parking lock control unit (type 242.890)	5
77	Trailer recognition control module	25
78	Trunk Lid/Tailgate Control Unit	40
	Special Vehicle Fuse Box	40
79	SAM management module	40
80	SAM management module	40
81	Fan controller	40
82	Ceiling Control Panel	10
83	Electronic ignition lock control module	7.5
84	Upper block control panel	5
85	EDW / Tow Protection / Interior Monitor Control Module	5
86	Antenna amplifier / mobile communication compensator (from 06/01/2016) Antenna amplifier FM, AM and ZV	5
87	Diagnostic connector	10
88	instrument cluster	10
89	Outdoor lighting switch	5
90	Intelligent radar sensor in rear bumper left and right	5
91	Footwell Light Switch, Pedal Sensor Battery management module (type 242.890)	5
92	Fuel pump fuse	5
	type 242.890: Transmission interface control unit	5
93	Electric parking brake control module	5
94	Passenger Restraint System (SRS) Control Module	7.5
95	Weight Sensing System Control Module, Occupancy Detection and AKSE, Front Passenger Seat	7.5
96	Tailgate wiper motor	15
97	Mobile phone electrical plug	5
98	SAM control unit	5
99	Tire pressure monitoring control unit	5
100	DIRECT SELECT interface (engine 133)	5
101	All-wheel drive control unit	10
102	Remote radio remote control receiver for auxiliary heater	5
	Type 242.890: Transmission control unit
	AMG, from 01.09.2015: Drive mode control unit
	as of 06/01/2016: Antenna switch for telephone and auxiliary heater
103	HERMES Control Unit, Emergency Call System Control Unit, Telecommunication Services Communication Module	5
104	Media Connectivity Module, Media Interface Control Unit	5
105	Satellite Digital Audio Radio (SDAR) Control Unit, Digital Audio Broadcasting Control Unit	5
	tuner module	7.5
106	Multifunction camera	5
107	Digital TV tuner	5
108	Rear View Camera	5
	as of 06/01/2016: Rear view camera	7.5
109	Electrical plug connection socket outlet for cargo	20
110	Motorsound control unit, COMAND control module, Audio module	30