Mercedes-Benz C-Class 2000-2007, a prominent presence on American roads, is a symbol of German engineering excellence. This midsize luxury sedan offers a blend of sophistication and performance, appealing to discerning drivers in the United States.
Mercedes C-Class featured a range of engines, including V6 and V8 options, delivering a compelling mix of power and efficiency. Its suspension and handling provided a comfortable yet sporty driving experience, and the lavish interior was a testament to Mercedes-Benz’s commitment to luxury.
Despite its remarkable design and performance, the Mercedes C-Class 2000-2007 was not without its common issues. Electrical problems, including issues with the power windows and central locking systems, were occasionally reported. Additionally, the transmission conductor plate and valve body in some models were known to require maintenance or replacement over time.
For those in need of a fuse and relay diagram for the Mercedes, this article will provide the essential information. Understanding the location and purpose of fuses and relays is vital for both maintenance and troubleshooting electrical problems in your Mercedes C-Class.
C-Class remained a symbol of luxury and performance on American roads. With proper care and timely maintenance, it continued to be a preferred choice for those who sought a premium driving experience.
Contents
Fuses and relays Mercedes-Benz W203
Fuses and relays for Mercedes-Benz W203 2000, 2001, 2002, 2003, 2004, 2005, 2006 and 2007 are located in the engine compartment, vehicle interior and luggage compartment. Mercedes-Benz W203 fuses protect electrical circuits and vehicle equipment from overloads and short circuits. Mercedes-Benz W203 relays control the correct operation of the vehicle’s electrical equipment.
Description
| 1 | Air conditioning/heater control unit – in the heater control panel |
| 2 | A/C/Heater Blower Control Module – Next to Blower Motor |
| 3 | Air purity sensor (air conditioning system) |
| 4 | Sunlight sensor (air conditioning system) |
| 5 | Antenna signal amplifier – 1, upper part of rear window |
| 7 | Anti-theft control unit (combined with multifunction control unit) – left side of luggage compartment |
| 8 | Vehicle Tilt Sensor (Anti-theft System) – Left Side of Luggage Compartment |
| 9 | Anti-theft alarm sound – behind the wheel arch trim |
| 10 | Volume change sensors (anti-theft system) |
| 11 | Audio system unit – in navigation system |
| 12 | Audio output amplifier (if equipped) – right luggage compartment |
| 13 | Additional heater control unit |
| 14 | Auxiliary heater remote control receiver – under dash (rear luggage compartment) |
| 15 | Accumulator battery |
| 16 | Brake booster vacuum pump control unit |
| 17 | Central locking signal sensor (infrared) – in the driver’s door handle |
| 18 | Diagnostic connector (DLC) |
| 19 | Driver’s door electrical control unit |
| 20 | Left rear door electrical control unit |
| 21 | Passenger door electrical control unit |
| 22 | Right rear door electrical control unit |
| 23 | Fuse/Relay Box, Engine Compartment 1 |
| 24 | Fuse/relay block instrument panel |
| 25 | Fuse/Relay Box, Luggage Compartment |
| 26 | Headlight control unit, left (models with xenon headlights) |
| 27 | Headlight control unit, right (models with xenon headlights) |
| 28 | Sound signals 1/2 – behind the radiator grille |
| 29 | Ignition switch control unit |
| 30 | Electronic immobilizer control unit – (combined with ignition switch control unit) |
| 31 | Turn signal/hazard warning relay – in multifunction control unit 2 |
| 32 | Lighting control unit – behind the headlight switch |
| 34 | Multi-function control unit 1 – attached to the fuse/relay box in the engine compartment – functions: Interior lamps, headlights, horns, windshield wipers, air conditioning pressure control, headlight washers, coolant level, brake fluid level, thermometer, electric drive door mirrors |
| 35 | Multifunction control unit 2 – connected to fuse/relay box, luggage compartment – functions: Central locking, fuel level, anti-theft system, hazard warning lights, rear window defroster, tail lights, trunk lid opener, rear window wiper (station wagon) |
| 36 | Navigation system control unit |
| 37 | Ambient temperature sensor |
| 38 | Parking system control unit – under the panel, in the rear part of the luggage compartment |
| 39 | Rain sensor – upper center of windshield |
| 40 | Electric seat control unit (with memory), front left – under the seat |
| 41 | Electric seat control unit (with memory), front right – under the seat |
| 42 | Seat heating control unit, front. – in the switch block |
| 43 | Electronic transmission control unit – sequential manual transmission |
| 44 | Side impact sensor, left – under the rear seat |
| 45 | Side impact sensor, right – under the rear seat |
| 46 | Electronic control unit SRS |
| 47 | Steering column electrical control unit – behind the steering wheel |
| 48 | Steering column lock control unit – integrated in the ignition switch control unit |
| 49 | Electric sunroof control unit |
| 50 | Body height sensor, front (models with xenon headlights) – front stabilizer bar |
| 51 | Body height sensor, rear (models with xenon headlights) – rear axle |
| 52 | Telephone connection module – under the panel, in the rear part of the luggage compartment |
| 53 | Telephone interface control unit – under the panel, in the rear part of the luggage compartment |
| 54 | Telephone transceiver – under the panel, in the rear of the luggage compartment |
| 55 | Trailer electrical control unit – under the panel, in the rear part of the luggage compartment |
| 56 | Electronic transmission control unit |
| 57 | Gear shift control unit – automatic transmission selector |
| 59 | Voice activation system unit – under the panel, in the rear of the luggage compartment |
| 60 | Fuse/Relay Box, Engine Compartment 2 |
F32 – power fuse block
F34 – Fuse box in the instrument panel
N10/1 – Fuse and relay box in the engine compartment
N10/2 – Trunk fuse and relay block
Fuse box in trunk
Photo example
Assignment of the fuses and relay in the trunk
| № | Circuit protected | Amp |
|---|---|---|
| 1 | Front passenger front seat adjustment control unit with memory Front passenger partially-electric seat adjustment switch |
30 |
| 2 | Driver front seat adjustment control unit with memory Driver partially-electric seat adjustment switch |
30 |
| 3 | Dome lamp Right luggage compartment lamp Left luggage compartment lamp STH radio remote control receiver |
7.5 |
| 3 | TV tuner (up to 29.2.04) TV tuner (MOST) (as of 1.4.04) |
20 |
| 4 | Fuel pump relay (N10/2kA) | 20 |
| 5 | Valid for engine 112.961 (up to 31.3.04): Charge air cooler circulation pump
Valid without engine 112.961: Backup relay 2 |
20 |
| 6 | Spare | 25 |
| 7 | Backup relay 1 | 7.5 |
| 8 | Amplifier module, window antenna Alarm signal horn (H3) ATA [EDW] inclination sensor |
7,5 |
| 9 | Overhead control panel control unit | 25 |
| 10 | Heated rear window | 40 |
| 11 | Spare | 20 |
| 12 | Interior socket Valid for model 203.0 USA version (up to 31.3.04): Power outlet |
15 |
| 13 | Multicontour seat pneumatic pump Voice control system control unit Rear dome lamp Rear dome lamp PTS warning indicator PTS control unit Japan version: VICS+ETC voltage supply separation point. |
5 |
| 14 | Tailgate wiper motor | 15 |
| 15 | Fuel filler cap polarity change relay 1 Fuel filler cap polarity change relay 2 |
10 |
| 16 | Voice control system control unit | 20 |
| 17 | Trailer recognition control unit | 20 |
| 18 | Trailer hitch socket (13-pin) | 20 |
| 19 | Multicontour seat pneumatic pump | 20 |
| 20 | Rear window roller blind relay Valid for model 203.2/7 USA version: Power outlet |
15 |
| Relay | ||
| A | Fuel pump relay | |
| B | Relay 2, terminal 15R | |
| C | Reserve relay 2 | |
| D | Reserve relay 1 | |
| E | Rear window defroster relay | |
| F | Relay 1, terminal 15R | |
| G | Filler cap relay, polarity reverser 1 | |
| H | Filler cap relay, polarity reverser 2 |
Passenger Compartment Fuse Panel
Assignment of the fuses in the instrument panel
| № | Circuit protected | Amp |
|---|---|---|
| 21 | Left front door control unit | 30 |
| 22 | Right front door control unit | 30 |
| 23 | Up to 30.11.04: Central gateway control unit | 15 |
| 24 | CD player with changer (in glove compartment) | 7.5 |
| 25 | Upper control panel control unit | 30 |
| 26 | Sound amplifier | 25 |
| 27 | Driver-side front seat adjustment control unit, with memory Special vehicle multifunction control unit (SVMCU [MSS]) |
30 |
| 28 | Spare | 30 |
| 29 | Driver-side front seat adjustment control unit, with memory Driver-side front seat adjustment control unit, with memory Special vehicle multifunction control unit |
30 |
| 30 | Heating systems recirculation unit | 40 |
| 31 | EIS [EZS] control unit Electric steering lock control unit |
20 |
| 32 | Left rear door control unit | 30 |
| 33 | Right rear door control unit | 30 |
| 34 | Cell phone separation point up to 31.5.01: Telephone and TELE AID transmitter/receiver, D2B Telephone transmitter and receiver unit, D2B Telephone interface E-net compensator up to 31.5.01, Japan version: E-call control unit |
7.5 |
| 34 | up to 31.3.04: Front passenger front seat adjustment control unit with memory as of 1.4.04: Passenger-side front seat adjustment control unit with memory up to 31.5.03, Taxi: Special vehicle multifunction control unit as of 1.6.03, Taxi: Special vehicle multifunction control unit as of 1.6.01, Police: Special vehicle multifunction control unit |
15 |
| 34 | as of 1.4.04: Front passenger front seat adjustment control unit with memory as of 1.4.04, Taxi: Special vehicle multifunction control unit |
30 |
| 35 | up to 31.3.04 : STH heater unit | 30 |
| 35 | as of 1.4.04 : STH heater unit | 20 |
| 36 | up to 31.3.04, Police: Interior socket | 30 |
| 36 | Valid for engine (612.990) (up to 29.2.04): Charge air cooler circulation pump as of 1.4.04, Japan version: Audio gateway control unit |
15 |
| 36 | Universal Portable CTEL Interface (UPCI [UHI]) control unit | 7.5 |
| 37 | Charge air cooler circulation pump up to 29.2.04: Brake booster vacuum pump control unit |
25 |
| 38 | up to 29.2.04:Passenger-side front seat adjustment control unit with memory as of 1.4.04, Police:Special vehicle multifunction control unit (SVMCU [MSS]) |
30 |
| 39 | Spare | 30 |
| 40 | Passenger-side front seat adjustment control unit with memory Universal Portable CTEL Interface (UPCI [UHI]) control unit Cell phone separation point Telephone interface E-net compensator as of 1.6.01, MB standard telephone: Telephone transmitter and receiver unit, D2B as of 1.6.01, TELE AID: Telephone and TELE AID transmitter/receiver, D2B as of 1.6.01, Canadian vehicles: Via the trunk lid/FFS [RBA] separation point the trunk lid emergency release switch and the rear SAM control unit with fuse and relay module USA version: Via the trunk lid/FFS [RBA] separation point the trunk lid emergency release switch and the rear SAM control unit with fuse and relay module as of 1.4.04, Japan version: E-call control unit |
7.5 |
| 40 | up to 31.5.01: Special vehicle multifunction control unit | 30 |
| 41 | HEAT control and operating unit up to 31.5.01: AAC [KLA] control and operating unit Comfort AAC [kLa] control and operating unit |
7.5 |
| 41 | as of 1.6.01: AAC [KLA] control and operating unit Comfort AAC [KLA] control and operating unit |
15 |
| 42 | Instrument cluster | 7.5 |
Engine Compartment Fuse Box
Assignment of the fuses and relay in the engine compartment
| № | Circuit protected | Amp |
|---|---|---|
| 43a | Fanfare horn relay | 15 |
| 43b | Fanfare horn relay | 15 |
| 44 | Telephone and TELE AID transmitter/ receiver, D2B Telephone transmitter and receiver unit, D2B Cell phone separation point |
5 |
| 45 | Restraint systems control unit | 7.5 |
| 46 | Wiper ON/OFF relay Wiper speed 1 and 2 relay |
40 |
| 47 | Glove compartment illumination with switch Front cigar lighter (with illumination) |
15 |
| 48 | Valid for engine 612.990 (up to 31.3.04): Brake booster vacuum pump control unit Valid for engine 112 and engine 113: Circuit 15 connector sleeve (fused) Valid for engine 646, USA version (up to 31.3.04): Circuit 30 connector sleeve Valid for engine 646 (as of 1.4.04): O 2 sensor upstream of TWC [kAt] connector |
15 |
| 49 | Restraint systems control unit | 7.5 |
| 50 | Light switch module Valid for engine 612.990: Glow output stage (up to 31.3.04), Hot film mass air flow sensor (1.4.04 up to 30.11.04) |
5 |
| 51 | AAC with integrated control additional fan motor Instrument cluster Valid for code (581) comfort automatic air conditioning: C-AAC [K-KLA] multifunction sensor, C-AAC [K-KLA] sun sensor (4 in total), Left front lamp unit, Right front lamp unit Valid for AMG vehicles: Charge air cooler circulation pump Valid for model 203.0 (up to 31.7.01): SPS [PML] control unit |
7.5 |
| 52 | Starter | 15 |
| 53 | Starter relay Rear SAM control unit with fuse and relay module Valid for engine 611/612/642/646: CDI control unit |
25 |
| 53 | Valid for gasoline engines: Starter relay Rear SAM control unit with fuse and relay module Valid for engine 111/271/272: ME-SFI [ME] control unit Valid for engine 112/113: ME-SFI [ME] control unit Circuit 87M1e connector sleeve |
15 |
| 54 | Valid for engine 271.940: ME-SFI [ME] control unit Purge control valve (USA version) Activated charcoal canister shutoff valve Valid for engine 271.942: NOX (nitrogen oxides) control unit Valid for engine 642/646: CDI control unit Valid for engine 642/646: Circuit 30 connector sleeve |
15 |
| 54 | Valid for engines 611/612: CDI control unit Valid for engine 611/612 (up to 30.11.04): Vent line heater element |
7.5 |
| 55 | Steering angle sensor Distronic: DTR control unit Valid for transmission 722: ETC [EGS] control unit (up to 31.5.04) Electronic selector lever module control unit Electric controller unit (VGS) Valid for transmission 716: Gear recognition switch Automated manual transmission control unit |
7.5 |
| 56 | ESP and BAS control unit Stop light switch |
5 |
| 57 | Steering angle sensor (up to 31.5.02) EIS [EZS] control unit Steering column module (as of 1.6.02) Valid for engine 112/113: ME-SFI [ME] control unit |
5 |
| 58 | Valid for transmission 716: SEQ hydraulic pump | 40 |
| 59 | ESP and BAS control unit | 50 |
| 60 | ESP and BAS control unit | 40 |
| 61 | Valid for transmission 716: Automated manual transmission control unit | 15 |
| 62 | Data link connector Light switch module Stop light switch |
5 |
| 63 | Light switch module | 5 |
| 64 | Radio Radio and navigation unit COMAND operating, display and control unit |
10 |
| 65 | Valid for engine 112/113: Electric air pump | 40 |
| Relay | ||
| I | Fanfare horn system relay | |
| K | Terminal 87 relay, chassis | |
| L | Wiper speed 1 and 2 relay | |
| M | Terminal 15R relay | |
| N | SEQ [ASG] pump control relay (with Sequentronic automated manual transmission (ASG)) | |
| O | Air pump relay (engines 112, 113, 271 only) | |
| P | Terminal 15 relay | |
| Q | Wiper ON/OFF relay | |
| R | Terminal 87 relay, engine | |
| S | Starter relay |
Front Prefuse Box
An additional high power fuse block in the form of fuse links is installed next to the battery.
Photo example
| № | Circuit protected | Amp |
|---|---|---|
| 1 | Interior fusebox | 125 |
| 2 | Luggage fusebox | 200 |
| 3 | Additional fuse holder 1, spare wheel well | 125 |
| 4 | Engine fusebox | 200 |
| 5 | Engine and AC electric suction fan with integrated control Valid for diesel engines: Glow output stage |
125 |
| 6 | Engine fusebox | 60 |
