Mercedes 202 passenger car of the German auto manufacturer from the C-class series which was produced in 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001 with different engine options ( C180 , C200, C220 CDI, C230, C240, C280) in the w202 sedan and S202 station wagon body. During this time, the model was restyled. In this publication you will find information about the location of all electronic control units, a detailed description of the fuses and relays of the Mercedes 202 with block diagrams and photo examples of execution. Note the cigarette lighter fuse.
The location of the blocks and the purpose of the elements in them may differ from the one shown and depends on the year of manufacture and the level of equipment of your car. Check the information with your diagrams on the brochures in the covers of the blocks or next to them.
Example of a brochure for a unit in the trunk
Location
General layout of electronic control units
Description
| 1 | Electronic air conditioning control unit |
| 2 | Antenna Signal Booster – Ceiling Panel (Universal) |
| 3 | Anti-theft alarm control unit – right side of luggage compartment |
| 7 | Vehicle tilt sensor (anti-theft system) |
| 8 | Anti-theft alarm horn – behind the front left wheel arch trim |
| 9 | Volume change sensor (anti-theft system), left – center pillar |
| 10 | Volume change sensor (anti-theft system), right – center pillar |
| 11 | Audio Output Amplifier – Left Luggage Compartment |
| 12 | Additional heater control unit |
| 13 | Battery – spare wheel niche |
| 14 | Central locking control unit – functions: Rear window defroster, interior light – rear, anti-theft alarm, boot lid/rear door light, boot lid/rear door lock – right side of luggage compartment |
| 15 | Diagnostic Link Connector (DLC) |
| 16 | Door electrical equipment control unit, driver’s side |
| 17 | Door electrical equipment control unit, passenger side |
| 18 | Control unit for electrical equipment of the door, driver’s side (rear) |
| 19 | Door electrical equipment control unit, passenger side (rear) |
| 20 | Electric window lift control unit/electric door mirror control unit – in the center console switch block |
| 21 | Fuse/Relay Box, Luggage Compartment (Spare Wheel Compartment) |
| 22 | Fuse/Relay Box, Engine Compartment 1 |
| 23 | Fuse/Relay Box, Engine Compartment 2 |
| 24 | Headlight corrector control unit (xenon lamps) |
| 25 | Sound signals – behind the front bumper |
| 26 | Ignition switch control unit |
| 29 | Multifunctional control unit 1 – functions: Central locking, hazard warning lights, rear window defroster, direction indicators, windscreen wipers, headlight washers, air conditioning, head restraints (rear), horns |
| 30 | Multifunctional control unit 2-functions: Interior lighting lamps, sunroof, vanity mirror lighting lamps |
| 31 | Navigation system control unit – spare wheel niche |
| 32 | Ambient air temperature sensor |
| 33 | Parking system control unit – right footwell |
| 34 | Rain sensor – in the interior rearview mirror |
| 35 | Rear Window Wiper/Washer Relay – Behind Lower Tailgate Trim (Wagon) |
| 36 | Relay Block – Functions: Overload/Surge Protection Relay, Starter Relay, Exhaust Air Injection Pump Relay (Gasoline), Transmission Control System Relay (Diesel) |
| 37 | Seat heating control unit, front – in switch block |
| 38 | Side impact sensor, left – under the front seat |
| 39 | Side impact sensor, right – under the front seat |
| 40 | SRS Electronic Control Unit |
| 41 | Body height sensor, front – headlight control (xenon lamps) |
| 42 | Body height sensor, rear – headlight control (xenon lamps) |
| 43 | Telephone Interface Control Unit – Spare Wheel Recess |
| 44 | Telephone Interface Control Unit – Left Side of Luggage Compartment (for Mobile Phone) |
| 45 | Telephone Interface Control Unit – Right Side of Trunk (For Mobile Phone) (Wagon) |
| 46 | Electronic Transmission Control Unit – Front Right Footwell |
| 48 | Voice Activation System Unit – Left Side of Luggage Compartment |
| 49 | Voice Activation System Unit – Right Side of Trunk (Wagon) |
Blocks under the hood
Main fuse and relay box
It is located under the hood on the left side of the engine compartment and can consist of two sections (fuses and relays).
Relay
Option 1
Scheme
Designation
- Horn relay
- Windshield Washer Pump Relay
- Windshield Wiper Motor Relay 1
- Windshield wiper motor relay 2
- Headlight Washer Pump Relay
- ABS Pump Motor Relay (TCS/ESP)
Option 2
Scheme
Purpose
- A – K3/1 Relay for additional heating of the exhaust turbo pipe (PSV)
- B – K20 Pre-fuel pump relay
- C/D – K9 Additional fan relay
- E – K2 Headlight wiper/washer relay
- F – K39 Sound signal relay
- G – K19/1 Additional module relay
- H – K17 Fan relay
- K – N10 Combination relay (direction indicators, heated rear window, windscreen wiper motor, etc.)
- L – N7 Lamp control relay
Fuses
Option 1
Scheme
Transcript
| F1 | (5A) Seat heating control unit (front), seat belt drive (comfort) |
| F2 | (5A) Seat occupant sensor, side impact sensors, seat belt pretensioner control unit |
| F3 | (15A) Audio system, telephone, voice activation system unit |
| F4 | (5A) Instrument cluster |
| F5 | (15A) Additional equipment power socket (station wagon), navigation system, sun blind |
| F6 | (7.5A) Folding rear view mirrors on the doors |
| F7 | (7.5A) Electric door mirrors, electric window lifters, rheostat for adjusting the brightness of the instrument cluster illumination, reversing light switch, rear door/trunk lid lock, navigation system, telephone (06/98), control unit (in case of an accident) (06/98-05/99) |
| F8 | (30A) Door electrical control unit, driver side |
| F9 | (25A) Sunroof, interior lights, rain sensor, full door locking, instrument cluster lighting rheostat, auto-dimming mirrors, remote central locking system |
| F10 | (15A) Audio system, telephone |
| F11 | (20A) Seat heater |
| F12 | (25 A) Audio system |
| F13 | (15A) Reversing light(s) (06/98), headlight range control unit (xenon lamps) |
| F14 | (5A) Parking system control unit |
| F15 | (15A) Rear Window Wiper/Washer (Wagon) |
| F16 | (5A) Stability Control System |
| F17 | (30A) Door electrical equipment control unit, driver’s side (rear) |
| F18 | (25A) Direction indicator repeaters (^05/98), trailer electrical equipment socket |
| F19 | (10A) Instrument cluster, lamp health monitoring unit, daytime running light control unit |
| F20 | (15A) Air conditioning, heating/ventilation |
| F21 | — |
| F22 | (10A) Combination switch (windshield wiper/washer, turn signals, low/high beam, headlight washers) |
| F23 | (15 A) Cigarette lighter fuse , glove compartment light |
| F24 | (15A) Front/rear side lights (right), trailer electrical socket (rear left side light), instrument cluster, number plate light, cigarette lighter light, headlight washers |
| F25 | (7.5A) Front/rear side lights (right), trailer electrical equipment socket (rear right side light) |
| F26 | (7.5A) Fog lights, trailer electrical socket (fog lights) |
| F27 | (15A) Steering column adjustment drive |
| F28 | (10A) Cigarette lighter , mini-bar |
| F29 | (30A) Air conditioner/heater fan motor |
| F30 | (10A) Instrument cluster, air conditioning, heating/ventilation |
| F31 | (7.5A/15A) Right headlight – low beam |
| F32 | (7.5A/15A) Left headlight – low beam |
| F33 | (7.5A) Right headlight – high beam |
| F34 | (7.5A) Left headlight – high beam |
| F35 | (15A) Fog lights |
| F36 | — |
| F37 | — |
| F38 | (30A/40A/60A) Air Conditioner |
| F39 | — |
| F40 | (10A) Sound signals |
| F41 | (15A) Direction indicators, instrument cluster lamps – indicators, horns, windshield wiper/washer, rain sensor, rear window defroster, cooling fan motor, auxiliary heating/air conditioning, headlamp washers, hazard warning lights |
| F42 | (7.5A) Windshield washer fluid heater |
| F43 | (7.5A) Windshield washer pump motor |
| F44 | (40A) Windscreen wipers, rain sensor |
| F45 | (15A) Headlight washers |
Fuse number 23 is responsible for the cigarette lighter.
Option 2
Scheme
Description
| F1 | (7.5A) Direction indicators |
| F2 | (15A) Sound signals, heater control unit |
| F3 | (15A) Brake lights, instrument cluster, lamp health monitoring unit, windshield washer nozzle heaters |
| F4 | (7.5A) Low beam – right headlight |
| F5 | (7.5A) Low beam – left headlight |
| F6 | (7.5A) High beam – right headlight |
| F7 | (7.5A) High beam – left headlight, high beam indicator |
| F8 | (10A) Fog lights |
| F9 | (30A) Heater Fan Motor |
| F10 | (15A) Instrument cluster and hazard warning lights |
| F11 | (40A) Rear window defroster |
| F12 | (10A) Air conditioning system, heater |
| F13 | (40A) Windshield wiper motor, windshield washers, high beam switch |
| F14 | (15A) Cigarette lighter , glove compartment light |
| F15 | (15A) Front side light – right, rear side light – right, instrument cluster illumination, license plate illumination lamps |
| F16 | (7.5A) Front side light – left, rear side light – left |
| F17 | (7.5A) Rear fog light |
| F18 | (7.5A) Heater Fan Motor Control Unit, Air Conditioner Condenser Fan Motor |
| F19 | (15A) Trailer electrical socket |
| F20 | (7.5A) SRS indicator |
| F21 | (15A) Audio system, telephone, seat heating control unit |
| F22 | (10A) Rear window blinds |
| F23 | (15A) Interior lights, anti-theft alarm, rear headrests, rear window wiper/washer |
| F24 | (15A) Reversing lights, electric door mirrors |
| F25 | (20A) Seat heater |
| F26 | (15A) Audio system, telephone |
| F27 | (15A) Interior lights, luggage compartment lights, central locking, anti-theft system |
| F28 | — |
| F29 | (30A) Air conditioner condenser fan |
Fuse number 14 is responsible for the cigarette lighter.
Option 3
Scheme
Designation
| F1 | (7.5A) Low beam – right headlight |
| F2 | (10A/15A) Cigarette lighter , glove compartment light, audio system |
| F3 | (10A) Audio system, heater control, air conditioning |
| F4 | (15A) Direction indicators, hazard warning lights, clock |
| F5 | (20 A) Sound signals, heater control unit, air conditioner |
| F6 | (7.5A) Direction indicators – left |
| F7 | (7.5A) Low beam – left headlight |
| F8 | (7.5A) Rear window defroster, interior rear view mirror |
| F9 | (7.5A) Cigarette lighter illumination lamp, license plate illumination lamps, instrument cluster |
| F10 | Spare |
| F11 | (7.5A) Air conditioner |
| F12 | (10A) Brake lights, instrument cluster, lamp health monitoring unit |
| F13 | (30A) additional heater fan motor |
| F14 | (30A) Heater Fan Motor |
| F15 | (30A) Windshield wiper motor |
| F16 | (30A) Rear window defroster |
| F17 | (40A) Electric motor for air supply pump |
| F18 | (7.5A) Front side light – left, rear side light – left |
| F19 | (7.5A) High beam – right headlight |
| F20 | (10A/15A) Seat heaters, audio system, telephone, sun blind – rear |
| F21 | (7.5A) Antenna |
| F22 | (10A) Fog lights |
| F23 | (15A) Diagnostic connector, overload protection, Evaporative emission control valve, EGR valve, Variable valve timing actuator, glow plug relay |
| F24 | (10A) Front side light – left, rear side light – left |
| F25 | (7.5A) High beam – left headlight, high beam indicator |
| F26 | (7.5A) SRS indicator, electric window control unit, telephone |
| F27 | (7.5A) Local lighting lamps interior lighting lamp |
| F28 | (7.5A) Rear fog lights |
| F29 | (15A) Reversing lights, electric door rear-view mirrors, door rear-view mirror heaters, windshield washer nozzle heaters, gear selector position sensor |
| F30 | (10A) Headlight washer/cleaner |
| F31 | Spare |
| F32 | (7.5A) Diagnostic unit |
| F33 | (15A) Interior lighting, trunk lighting, vanity mirror lighting, central locking |
| F34 | (7.5A) Electric motors for adjusting headrests, daytime lighting system |
| F35 | (7.5A) Interior Light – Front, Anti-Theft System, Trailer Electrical Control Unit |
Fuse number 2 is responsible for the cigarette lighter.
Additional fuse and relay box
It is installed in the right part of the engine compartment.
Purpose
| 1 | Electronic engine control unit |
| 2 | Electronic control unit ABS/ESР |
| 3 | Relay block – includes: Overload/voltage surge protection relay, starter relay, exhaust air supply system pump relay – gasoline |
| 4 | Starter relay |
| 5 | Diagnostic Link Connector (DLC) |
| F1 | (7.5A) Diagnostic Link Connector (DLC) |
| F2 | (10A) ABS/ESP – petrol |
| F3 | (10A/25A) Automatic transmission |
| F4 | (15A) Mercedes 202 engine management system – petrol |
| F5 | (20A) Engine Management System – Petrol |
| F6 | (15A) Engine Management System – Petrol |
| F7 | (40A) Exhaust Air Injection System Pump – Petrol |
Block in the trunk
In the luggage compartment next to the battery there is another block with fuses. Next to it is the fuel pump relay.
Transcript
| F1 | 25A Audio system |
| F2 | 7.5A Multifunctional Control Unit |
| F3 | 20A Anti-theft system |
| F4 | 7.5A Antenna |
| F5 | 7.5A Interior Lights |
| F6 | 25A Trailer Electrical Equipment |
| F7 | 30A Electric window lifter – rear |
| F8 | 30A Electric window lifters – front |
| F9 | 20A Luke |
| F10 | 30A Electric seat drive – left |
| F11 | 20A Electric seat drive – left |
| F12 | 20A Electric seat drive – right |
| F13 | 20A Electric seat drive – right |
Option 2
Scheme
Description
| F1 | 25A Fuel Pump |
| F2 | 30A Central locking control unit |
| F3 | 30A Electric window lifter (driver’s door) |
| F4 | 40A Central locking control unit |
| F5 | 30A Electric window lift, driver side (rear) |
| F6 | 5A Interior light – rear, rear door/trunk lid light, electric seats |
| F7 | 5A Anti-theft system |
| F8 | — |
| F9 | — |
| F10 | 25A Electric drive left front seat |
| F11 | 25A Electric drive left front seat |
| F12 | 25A Right Front Seat Electric Drive |
| F13 | 25A Right Front Seat Electric Drive |
| F14 | — |
| F15 | — |
| F16 | — |
| F17 | — |
Option 3
Scheme
Designation
| F1 | 25A Electric seat (left) |
| F2 | 25A Electric seat (right) |
| F3 | 25A Electric seat (left) |
| F4 | 25A Electric seat (right) |
| F5 | 25A Audio system |
| F6 | 7.5A CD changer |
| F7 | 30A Electric window lifts – rear |
| F8 | 7.5A Anti-theft System Control Unit |
| F9 | 7.5A Multifunctional Control Unit |
| F10 | 30A Electric window lifts – front |
| F11 | 20A Anti-theft system, sound signals |
| F12 | 20A Seat Heater |
| F13 | 20A Luke |
| F14 | 25A Anti-theft system |
| F15 | Spare |
| F16 | Spare |
| F17 | 30A Telephone |
| F18 | 25A Trailer Electrical Equipment |
| F19 | Spare |