Mercedes GLA X156 – fuse and relay

Mercedes GLA X156 is a mini crossover produced by the German company Mercedes-Benz in 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021 with the designation GLA 180, GLA 200, GLA 220, GLA 250, GLA 45 AMG . In our material you will find a description of the fuses and relays Mercedes X156 with box diagrams, photo examples and locations. Note the fuse responsible for the cigarette lighter.

Mercedes X156

The purpose of the fuses and relays may differ from the one shown and depends on the year of manufacture and the level of equipment of your car.

Passenger compartment

In the cabin, the main fuse and relay box is located under the panel, on the passenger side under a protective cover.

Location 1


Diagram Mercedes 176


21150A Auxiliary electric heater (vehicles with diesel engine)
22200A ECO start-stop auxiliary battery relay
2330A Front left door control unit
2430A Front right door control unit
2530A SAM control unit
2610A ECO start-stop auxiliary battery cable termination
2730A Engine compartment fuse and relay module
285A Cabin Sound Generator Control Module (Type 176 with 651 Engine)
Thermal management unit (type 242.890)
2915A Trailer socket (up to 02.11.2014)
Trailer detection control unit (from 03.11.2014)
305A Trailer detection control unit
315A AWD control unit
325A Signals from the steering column electronic module control unit
335A Audio module/ COMAND system control panel
347.5A Climate control panel
3540A Heated rear window (type: 117, 176, 242, 246)
30A Heated rear window (type: 156)
367.5A Driver’s seat control unit
Lumbar adjustment control unit for driver’s seat
377.5A Audio module / COMAND system display
387.5A Supplemental Restraint System control unit
3910A Ceiling Control Panel
4015A Transmission control unit (engine 651)
5A Transmission control unit (type 242.890)
4130A Panoramic sliding sunroof control module
425A Audio module
COMAND control module
25A Audio module
435A Parking assistance control unit
4440A Front left seat belt reversible pretensioner
4540A Front right seat belt reversible pretensioner
467.5A Front passenger seat control unit
Lumbar support adjustment control unit for front passenger seat
477.5A Navigation module
Holder control unit for iPhone
25A Adaptive damping system control unit
497.5A Drive Kit Control Unit for iPhone
5A Fan motor COMAND
505A Camera cover control box
5230A Parking lock actuator signal
555A Telecom Services Communication Module
Control unit KEYLESS-GO
5610A Signals from the steering column electronic module control unit
5730A Multifunction control unit for special vehicle
7.5A Multifunction control unit for special vehicle
5A Terminal 87 relay Park lock actuator
5830A Special vehicle fuse box
5930A Front passenger seat control unit
6030A Driver’s seat control unit
6140A Speaker amplifier control unit
6220A Electric steering lock control unit (711 transmission)
6325A Fuel pump control unit
5A Transmission interface control unit (type 242.890)
64Control unit “Electronic Toll Collection”
DSRC Toll Communication Control Unit
655A Glove box light
6615A Special vehicle fuse box
5A Special vehicle interface
7025A Rear center console socket
7125A Socket in trunk
7225A Cigarette lighter with front ashtray illumination
Socket in salon
7330A Electric parking brake control unit
7430A Electric parking brake control unit
7520A Trailer recognition control unit
5A Battery management control unit (type 242.890)
7625A Trailer recognition control unit
5A Parking lock control unit (type 242.890)
7725A Trailer recognition control unit
7840A Tailgate/ Tailgate Power Control Module
40A Special vehicle fuse box
7940A SAM control unit
8040A SAM control unit
8140A Fan regulator
8210A Ceiling Control Panel
837.5A Electronic ignition lock control unit
845A Upper control box
855A EDW/ Tow protection/ Interior monitor control unit
865A FM, AM and ZV Antenna Amplifier
Antenna amplifier /compensator for mobile communication (from 06/01/2016)
8710A Diagnostic connector
8810A Instrument cluster
895A Outdoor lighting switch
905A Intelligent radar sensor in rear bumper, left
Intelligent radar sensor in the right rear bumper
915A Pedal control sensor
Footwell lighting switch
Battery management system control unit (type 242.890)
925A Fuel pump control unit
Transmission interface control unit (type 242.890)
935A Electric parking brake control unit
947.5A Supplemental Restraint System control unit
957.5A Occupancy recognition and AKSE, front passenger seat
Weight Sensing System control unit
9615A tailgate wiper motor
975A Mobile phone electrical plug
985A SAM control unit
995A Tire pressure monitoring control unit
1005A DIRECT SELECT interface (engine 133)
10110A AWD control unit
1025A Radio remote control receiver for auxiliary heater
Transmission control unit (type 242.890)
Drive mode control unit (AMG, from 09/01/2015)
Antenna switch for telephone and auxiliary heater (from 06/01/2016)
1035A Emergency call system control unit
Telecom Services Communication Module
HERMES control unit
1045A Multimedia interface control unit
Media Connectivity Module
1055A Digital audio broadcasting control unit
Satellite Digital Audio Radio (SDAR) control unit
7.5A Tuner module
1065A Multifunction camera
1075A Digital TV Tuner
1085A Rear view camera
7.5A Rear view camera (from 06/01/2016)
10920A Electrical plug socket for cargo
11030A Audio module
COMAND control module
Motorsound control unit
ARelay terminal 15
BRear window wiper relay
CRelay terminal 15R2
DHeated rear window relay
ERelay terminal 15R1
FRelay terminal 30g
GRelay terminal 87 parking lock actuator (type 242.890)

Fuses numbered 70, 71 and 72 are responsible for the cigarette lighters.

Engine compartment

Under the hood, on the left side of the engine compartment, there can be 2 fuse boxes.

Location of fuses box

Fuse and relay box

To access the unit, you need to remove the protective cover.



Diagram 1


2015A Alarm Siren
20220A Auxiliary heater control unit
5A Terminal 87 relay of the parking lock control unit (type 242.890)
20315A Front right headlamp
5A Transmission control unit (type 242.890)
20425A Electronic motion stabilization control unit
20515A Left horn
Sound signal right
2065A CDI control unit (engine 651)
Transmission control unit (type 242.890)
Brake booster vacuum pump relay (type 242.890)
Relay el. terminal circuits 87M (type 242.890)
2075A Relay el. terminal circuits 87M (diesel)
HV battery cooling shut-off valve (type 242.890)
Parking lock control unit (type 242.890)
2087.5A Terminal 87 relay (motors: 133, 607)
5A Fan motor (type 242.890)
20915A Front left headlight
Reserve (type 242.890)
2105A Heated front window relay
Starter pre-relay (type 176 from 01/09/2015, type 246 from 03/11/2014)
2117.5A CNG control unit (type 242.848)
15A Heating circuit circulation pump (type 242.890)
21215A Cable lug electr. terminal circuits 87M3 (motors 133, 270)
15A Ventilation line heating element (651 engine)
Heating element of the thermostat of the cooling system (engine 651)
EGR cooler bypass changeover valve (engine 651)
15A Lambda probe before catalytic converter (engine 607)
Boost pressure control servo (607 engine)
CDI control unit (engine 607)
15A Electric drive and charger coolant pump (type 242.890)
21315A Terminal 87 cable termination (motors 133, 270, 651)
15A Camshaft Hall sensor (engine 607)
CDI control unit (engine 607)
Dosing valve (engine 607)
Lambda probe after catalytic converter (engine 607)
15A Coolant pump 1 for battery cooling (type 242.890)
21410A Terminal 87 cable termination (motors 133, 270, 651)
15A Coolant pump 2 for battery cooling (type 242.890)
21520A Cylinder 1 ignition coil (petrol engines)
Cylinder 2 ignition coil (petrol engines)
Cylinder 3 ignition coil (petrol engines)
Cylinder 4 ignition coil (petrol engines)
Dosing valve (engine 651)
CDI control unit (engine 607)
Boost pressure control servo (607 engine)
Dosing valve (engine 607)
5A Thermal management unit (type 242.890)
Transmission gateway control unit (type 242.890)
High voltage power distributor (type 242.890 from 03.11.2014)
2165A ME control unit (petrol engines)
Transmission control unit (engine 607)
21725A Dual Clutch Transmission Fully Integrated Control Module (724 Transmission)
2185A Control unit for electronic stability control
2195A Parking lock control unit (type 242.890)
22010A Circulation pump for gearbox oil cooling system (gearbox 724)
22140A Vacuum pump (type 242.890)
2227.5A Electric air conditioning compressor (type 242.890)
2247.5A Electrical control module DISTRONIC
2255A Transmission control unit (type 242.890)
2265A CNG control unit (type 242.848)
Charger control unit (type 242.890)
Power electronics control unit (type 242.890)
2275A Power electronics control unit (type 242.890)
2285A Electric vehicle sound generator (type 242.890)
2295A Front left headlight
2305A Control unit for electronic stability control
2315A Front right headlamp
23215A Headlight control unit
2345A Transmission control unit (engine 607)
10A High voltage power distributor (type 242.890)
2357.5A Fan motor (607 motor)
Radiator Shutter Actuator (607 Engine)
Charge air cooler circulation pump (engine 133)
23640A SAM control unit
23740A Control unit for electronic stability control
23850A Heated windshield
23930ARrelay for wiper modes 1/2
240A25A Starter terminal 50 relay
7.5A Transmission control unit (type 242.890)
240B25A Terminal 15 relay (no support)
2417.5A High voltage electric heater system (type 242.890)
JHorn relay
KWiper speed relay 1/2
LWiper relay on/off
MStarter terminal 50 relay
Relay terminal 87C (type 242.890)
NRelay el. circuit terminals 87M
OTransmission oil coolant circulation pump relay
Relay terminal 87 parking lock control unit (type 242.890)
PReserve relay
QTerminal 15 relay (unprotected)
Power supply relay for brake booster vacuum pump (type 242.890)
RRelay terminal 15
SRelay terminal 87
THeated windshield relay

Fuse box

The high power fuse box is located next to the fuse and relay box.


Diagram 2


F1300A Generator / 400A DC voltage converter control unit (type 242.890)
F2200A Interior fuse block (petrol engines)
250A Interior fuse block (diesel engines)
F3100A Electric power steering control unit
F440A SAM control unit
F580A Fan motor
F670A Fuel heating control unit (engine 607)
F7125A DPF regeneration auxiliary heater control unit (engine 607)
F8100A Glow Plug Output Stage Module (Engines: 651, 607)
F32k1Decoupling relay (F32k1)


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