The Mercedes W168 represents the first generation of the A-Class in the Mercedes-Benz lineup which was designated A140, A150, A160, A170, A180, A190, A200 and A210 and was produced in 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004. During this time, the model has been restyled. In this publication you will find information about the location of all electronic control units, a description of the fuses and relays Mercedes w168 with box diagrams and photo examples of their execution. Select the cigarette lighter fuse.
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.
Location
Layout
Assignment
| 1 | Air conditioning control unit – in the heater control panel |
| 2 | Antenna signal booster |
| 3 | Anti-theft system control unit – interior lamps |
| 4 | Vehicle inclination sensor (anti-theft system) – in the anti-theft system control unit |
| 5 | Horn of the anti-theft system |
| 6 | Volume change sensors (anti-theft system) – in the anti-theft system control unit |
| 7 | Anti-theft signal control unit – in the immobilizer control unit |
| 9 | Auxiliary heater remote control receiver |
| 10 | Battery – passenger side legroom |
| 12 | Clutch control unit |
| 13 | Diagnostic connector (DLC) |
| 14 | Power window control unit – in the front power window control panel |
| 15 | Left front power window control unit – in power window motor |
| 16 | Left rear power window control unit – in power window motor |
| 17 | Right front power window control unit – in power window motor |
| 18 | Right rear power window control unit – in power window motor |
| 19 | Fuse box/relay dashboard |
| 20 | Fuse/Relay Box, Footwell |
| 21 | Fuse/Relay Box, Engine Compartment |
| 22 | Horns – behind the front bumper |
| 23 | Electronic immobilizer control unit |
| 24 | Immobilizer ring antenna – near the ignition switch |
| 26 | Lighting control unit – in the headlight switch |
| 27 | Multifunctional control unit – functions: central locking, direction indicators, sunroof – in the instrument cluster |
| 28 | Navigation system control unit – in audio unit |
| 29 | Ambient temperature sensor |
| 30 | Parking system control unit |
| 31 | Rain sensor – in the interior rearview mirror |
| 32 | Seat heating control unit – in the switch block |
| 33 | Side impact sensor, left |
| 34 | Side impact sensor, right |
| 35 | SRS electronic control unit |
| 36 | Telephone network connection module |
| 37 | Phone interface control unit |
| 39 | Windshield Wiper Intermittent Relay – Windshield Wiper Motor |
Passenger compartment
Fuse and relay box
The main fuse and relay box is located next to the battery, on the passenger side under a cover in the footwell. To remove the cover, turn the fastening clips.
Photo – example
Diagram
Designation
| 1 | 20A Gasoline engines: |
| Tank Vent Valve Fan Relay | |
| Fuel injection control unit | |
| Idle speed control unit | |
| EGR valve | |
| Lambda probe heater 1 | |
| Lambda probe heater 2 | |
| Diagnostic connector | |
| Tempomat | |
| boost relay | |
| Boost valve (US models) | |
| Fuel cut-off valve (US models) | |
| 10A Diesel engines: | |
| Fan relay | |
| Diesel power control unit | |
| diaphragm valve | |
| throttle valve | |
| EGR valve | |
| Catalyst temperature sensor | |
| 2 | 25A Engine control unit |
| Ignition coils | |
| fuel injectors | |
| Fuel pump relay | |
| Electronic accelerator | |
| Relay for blocking and disabling the starter | |
| 3 | 30A Vehicles without air conditioning: Engine cooling fan |
| 40A Vehicles with air conditioning: Engine cooling fan | |
| 4 | 7.5A Engine control unit |
| 5 | 40A Automatic clutch |
| 6 | 30A Fuel pump relay |
| 7 | 40A Vehicle lighting unit |
| 8 | 30A Starter Interlock and Disable Relay |
| 9 | 40A Wiper motor |
| 10 | 20/40A Hatch |
| Rear window cleaner | |
| 11 | 15A Cigarette lighter |
| 15A Steering column switch: | |
| glass cleaner | |
| Sound signal | |
| washer pump | |
| Radio navigation system | |
| 12 | 30A Socket in trunk |
| Radio | |
| Glove box light | |
| CD changer | |
| 13 | 30A Front door windows |
| 7.5A Power windows for all doors | |
| 14 | 10A Instrument panel (clock) |
| Wiper and washer relay | |
| Mobile phone | |
| 15 | 10A Airbag unit |
| Child seat recognition unit | |
| Side airbag sensor | |
| 16 | 15A Exterior mirror drive and mirror heater |
| Parking assistance | |
| 17 | 15A Horn |
| 18 | 10A Instrument panel |
| Transponder and signal receiver from the remote control | |
| ECM relay | |
| Fan relay | |
| 19 | 30A Drawbar |
| 20 | 15A Drawbar |
| 21 | 15A Drawbar |
| 22 | 25A Audio system |
| 23 | 7.5A Mirror illumination |
| 24 | Not used |
| 25 | Not used |
| 26 | Not used |
| 27 | Not used |
| 28 | 10A Instrument panel |
| Power windows | |
| 29 | 15A Central locking |
| Seat position recognition unit | |
| 30 | 7.5A Transponder and remote control signal receiver |
| Electronic instrument panel | |
| 31 | 25A Rear window heater |
| 32 | 15A Mobile phone |
| Radio receiver or radio navigation system | |
| CD changer | |
| Interior lighting | |
| 33 | 30A Power windows |
| 34 | 30A Fuel filter heater |
| 40A Supercharging. (US models) | |
| 35 | 10A Burglar alarm control unit |
| 2x light and sound alarm relays | |
| 36 | 25A Heated front seats |
| 37 | 10A Program switch |
| Coolant heater relay | |
| 38 | 10A Air conditioning compressor |
| Air mixing damper motor | |
| Cabin air temperature sensor | |
| Washer jet heater | |
| 39 | 7.5A Lighting module |
| reversing lamp | |
| 40 | 10A Brake lights |
| 41 | 10A Air conditioning compressor |
| Diagnostic connector | |
| 42 | Power windows |
| 43 | 15A ESP |
| Brake light switch | |
| 44 | 10A Transmission or automatic clutch control unit |
| 45 | 30A Interior heater blower |
| air conditioner fan | |
| 46 | 80A Fuse for on-board network |
| 47 | 60A Power steering pump |
| 48 | 60A Diesel engines: Preheat control unit |
| Relay | |
| К7 | Fuel pump relay (002 542 13 19) |
| К8 | Fuel and ignition control unit relay (002 542 25 19) |
| К9 | ESP/VGS relay or ESP/automatic transmission. VGS gearbox control unit (002 542 25 19) |
| К10 | Rear window heater relay (002 542 13 19) |
Fuses number 11 and 12 are responsible for the cigarette lighters.
Fuse box
Another fuse box is located on the back of the instrument panel, also closed with a protective cover.
Diagram
Allocation
- 7,5A – Left low beam headlight
- 7,5A – Right low beam headlight
- 15A – High beam, high beam indicator
- 7,5A – Left parking light, Rear left marker
- 15A – Right parking light, Right tail light, License plate light, Instrument panel, terminal 58
- 15A – Fog lights, Left rear fog light
Engine compartment
Under the hood, on the right side of the engine compartment, a block with a relay is installed.
Diagram
Appointment
| К1 | washer pump relay |
| К2.0 | horn relay |
| К2.1 | stability control relay (ESP) |
| К3 | relay for blocking and disabling the starter |
| К4 | radiator fan relay |
| К5 | stability control pump (ESP) relay |
| К6 | air pump relay (USA Models) |
Found a mistake or have something to add – write in the comments.
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