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.
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.
Diagram
Assignment
| 21 | 150A Auxiliary electric heater (vehicles with diesel engine) |
| 22 | 200A ECO start-stop auxiliary battery relay |
| 23 | 30A Front left door control unit |
| 24 | 30A Front right door control unit |
| 25 | 30A SAM control unit |
| 26 | 10A ECO start-stop auxiliary battery cable termination |
| 27 | 30A Engine compartment fuse and relay module |
| 28 | 5A Cabin Sound Generator Control Module (Type 176 with 651 Engine) |
| Thermal management unit (type 242.890) | |
| 29 | 15A Trailer socket (up to 02.11.2014) |
| Trailer detection control unit (from 03.11.2014) | |
| 30 | 5A Trailer detection control unit |
| 31 | 5A AWD control unit |
| 32 | 5A Signals from the steering column electronic module control unit |
| 33 | 5A Audio module/ COMAND system control panel |
| 34 | 7.5A Climate control panel |
| 35 | 40A Heated rear window (type: 117, 176, 242, 246) |
| 30A Heated rear window (type: 156) | |
| 36 | 7.5A Driver’s seat control unit |
| Lumbar adjustment control unit for driver’s seat | |
| 37 | 7.5A Audio module / COMAND system display |
| 38 | 7.5A Supplemental Restraint System control unit |
| 39 | 10A Ceiling Control Panel |
| 40 | 15A Transmission control unit (engine 651) |
| 5A Transmission control unit (type 242.890) | |
| 41 | 30A Panoramic sliding sunroof control module |
| 42 | 5A Audio module |
| COMAND control module | |
| 25A Audio module | |
| 43 | 5A Parking assistance control unit |
| 44 | 40A Front left seat belt reversible pretensioner |
| 45 | 40A Front right seat belt reversible pretensioner |
| 46 | 7.5A Front passenger seat control unit |
| Lumbar support adjustment control unit for front passenger seat | |
| 47 | 7.5A Navigation module |
| Holder control unit for iPhone | |
| 25A Adaptive damping system control unit | |
| 48 | Reserve |
| 49 | 7.5A Drive Kit Control Unit for iPhone |
| 5A Fan motor COMAND | |
| 50 | 5A Camera cover control box |
| 51 | Reserve |
| 52 | 30A Parking lock actuator signal |
| 53 | Reserve |
| 54 | Reserve |
| 55 | 5A Telecom Services Communication Module |
| Control unit KEYLESS-GO | |
| 56 | 10A Signals from the steering column electronic module control unit |
| 57 | 30A Multifunction control unit for special vehicle |
| 7.5A Multifunction control unit for special vehicle | |
| 5A Terminal 87 relay Park lock actuator | |
| 58 | 30A Special vehicle fuse box |
| 59 | 30A Front passenger seat control unit |
| 60 | 30A Driver’s seat control unit |
| 61 | 40A Speaker amplifier control unit |
| 62 | 20A Electric steering lock control unit (711 transmission) |
| 63 | 25A Fuel pump control unit |
| 5A Transmission interface control unit (type 242.890) | |
| 64 | Control unit “Electronic Toll Collection” |
| DSRC Toll Communication Control Unit | |
| 65 | 5A Glove box light |
| 66 | 15A Special vehicle fuse box |
| 5A Special vehicle interface | |
| 67 | Reserve |
| 68 | Reserve |
| 69 | Reserve |
| 70 | 25A Rear center console socket |
| 71 | 25A Socket in trunk |
| 72 | 25A Cigarette lighter with front ashtray illumination |
| Socket in salon | |
| 73 | 30A Electric parking brake control unit |
| 74 | 30A Electric parking brake control unit |
| 75 | 20A Trailer recognition control unit |
| 5A Battery management control unit (type 242.890) | |
| 76 | 25A Trailer recognition control unit |
| 5A Parking lock control unit (type 242.890) | |
| 77 | 25A Trailer recognition control unit |
| 78 | 40A Tailgate/ Tailgate Power Control Module |
| 40A Special vehicle fuse box | |
| 79 | 40A SAM control unit |
| 80 | 40A SAM control unit |
| 81 | 40A Fan regulator |
| 82 | 10A Ceiling Control Panel |
| 83 | 7.5A Electronic ignition lock control unit |
| 84 | 5A Upper control box |
| 85 | 5A EDW/ Tow protection/ Interior monitor control unit |
| 86 | 5A FM, AM and ZV Antenna Amplifier |
| Antenna amplifier /compensator for mobile communication (from 06/01/2016) | |
| 87 | 10A Diagnostic connector |
| 88 | 10A Instrument cluster |
| 89 | 5A Outdoor lighting switch |
| 90 | 5A Intelligent radar sensor in rear bumper, left |
| Intelligent radar sensor in the right rear bumper | |
| 91 | 5A Pedal control sensor |
| Footwell lighting switch | |
| Battery management system control unit (type 242.890) | |
| 92 | 5A Fuel pump control unit |
| Transmission interface control unit (type 242.890) | |
| 93 | 5A Electric parking brake control unit |
| 94 | 7.5A Supplemental Restraint System control unit |
| 95 | 7.5A Occupancy recognition and AKSE, front passenger seat |
| Weight Sensing System control unit | |
| 96 | 15A tailgate wiper motor |
| 97 | 5A Mobile phone electrical plug |
| 98 | 5A SAM control unit |
| 99 | 5A Tire pressure monitoring control unit |
| 100 | 5A DIRECT SELECT interface (engine 133) |
| 101 | 10A AWD control unit |
| 102 | 5A 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) | |
| 103 | 5A Emergency call system control unit |
| Telecom Services Communication Module | |
| HERMES control unit | |
| 104 | 5A Multimedia interface control unit |
| Media Connectivity Module | |
| 105 | 5A Digital audio broadcasting control unit |
| Satellite Digital Audio Radio (SDAR) control unit | |
| 7.5A Tuner module | |
| 106 | 5A Multifunction camera |
| 107 | 5A Digital TV Tuner |
| 108 | 5A Rear view camera |
| 7.5A Rear view camera (from 06/01/2016) | |
| 109 | 20A Electrical plug socket for cargo |
| 110 | 30A Audio module |
| COMAND control module | |
| Motorsound control unit | |
| Relay | |
| A | Relay terminal 15 |
| B | Rear window wiper relay |
| C | Relay terminal 15R2 |
| D | Heated rear window relay |
| E | Relay terminal 15R1 |
| F | Relay terminal 30g |
| G | Relay 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.
Fuse and relay box
To access the unit, you need to remove the protective cover.
Diagram
Designation
| 201 | 5A Alarm Siren |
| 202 | 20A Auxiliary heater control unit |
| 5A Terminal 87 relay of the parking lock control unit (type 242.890) | |
| 203 | 15A Front right headlamp |
| 5A Transmission control unit (type 242.890) | |
| 204 | 25A Electronic motion stabilization control unit |
| 205 | 15A Left horn |
| Sound signal right | |
| 206 | 5A 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) | |
| 207 | 5A Relay el. terminal circuits 87M (diesel) |
| HV battery cooling shut-off valve (type 242.890) | |
| Parking lock control unit (type 242.890) | |
| 208 | 7.5A Terminal 87 relay (motors: 133, 607) |
| 5A Fan motor (type 242.890) | |
| 209 | 15A Front left headlight |
| Reserve (type 242.890) | |
| 210 | 5A Heated front window relay |
| Starter pre-relay (type 176 from 01/09/2015, type 246 from 03/11/2014) | |
| 211 | 7.5A CNG control unit (type 242.848) |
| 15A Heating circuit circulation pump (type 242.890) | |
| 212 | 15A 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) | |
| 213 | 15A 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) | |
| 214 | 10A Terminal 87 cable termination (motors 133, 270, 651) |
| 15A Coolant pump 2 for battery cooling (type 242.890) | |
| 215 | 20A 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) | |
| 216 | 5A ME control unit (petrol engines) |
| Transmission control unit (engine 607) | |
| 217 | 25A Dual Clutch Transmission Fully Integrated Control Module (724 Transmission) |
| 218 | 5A Control unit for electronic stability control |
| 219 | 5A Parking lock control unit (type 242.890) |
| 220 | 10A Circulation pump for gearbox oil cooling system (gearbox 724) |
| 221 | 40A Vacuum pump (type 242.890) |
| 222 | 7.5A Electric air conditioning compressor (type 242.890) |
| 223 | Reserve |
| 224 | 7.5A Electrical control module DISTRONIC |
| COLLISION PREVENTION ASSIST control module | |
| 225 | 5A Transmission control unit (type 242.890) |
| 226 | 5A CNG control unit (type 242.848) |
| Charger control unit (type 242.890) | |
| Power electronics control unit (type 242.890) | |
| 227 | 5A Power electronics control unit (type 242.890) |
| 228 | 5A Electric vehicle sound generator (type 242.890) |
| 229 | 5A Front left headlight |
| 230 | 5A Control unit for electronic stability control |
| 231 | 5A Front right headlamp |
| 232 | 15A Headlight control unit |
| 233 | Reserve |
| 234 | 5A Transmission control unit (engine 607) |
| 10A High voltage power distributor (type 242.890) | |
| 235 | 7.5A Fan motor (607 motor) |
| Radiator Shutter Actuator (607 Engine) | |
| Charge air cooler circulation pump (engine 133) | |
| 236 | 40A SAM control unit |
| 237 | 40A Control unit for electronic stability control |
| 238 | 50A Heated windshield |
| 239 | 30ARrelay for wiper modes 1/2 |
| 240A | 25A Starter terminal 50 relay |
| 7.5A Transmission control unit (type 242.890) | |
| 240B | 25A Terminal 15 relay (no support) |
| 241 | 7.5A High voltage electric heater system (type 242.890) |
| Relay | |
| J | Horn relay |
| K | Wiper speed relay 1/2 |
| L | Wiper relay on/off |
| M | Starter terminal 50 relay |
| Relay terminal 87C (type 242.890) | |
| N | Relay el. circuit terminals 87M |
| O | Transmission oil coolant circulation pump relay |
| Relay terminal 87 parking lock control unit (type 242.890) | |
| P | Reserve relay |
| Q | Terminal 15 relay (unprotected) |
| Power supply relay for brake booster vacuum pump (type 242.890) | |
| R | Relay terminal 15 |
| S | Relay terminal 87 |
| T | Heated windshield relay |
Fuse box
The high power fuse box is located next to the fuse and relay box.
Diagram
Allocation
| F1 | 300A Generator / 400A DC voltage converter control unit (type 242.890) |
| F2 | 200A Interior fuse block (petrol engines) |
| 250A Interior fuse block (diesel engines) | |
| F3 | 100A Electric power steering control unit |
| F4 | 40A SAM control unit |
| F5 | 80A Fan motor |
| F6 | 70A Fuel heating control unit (engine 607) |
| F7 | 125A DPF regeneration auxiliary heater control unit (engine 607) |
| F8 | 100A Glow Plug Output Stage Module (Engines: 651, 607) |
| Relay | |
| F32k1 | Decoupling relay (F32k1) |
Found a mistake or have something to add – write in the comments.
I need to find the rear driver side window relay. I hear it clicking under the dash, not in passenger footwell box. Any ideas.
I cannot even determine which fuse powers the rear windows, (left). Any ideas?
I am having the same problem as you. Did you manage to figure out what the problem was?