Mercedes-Benz w220 fuse and relay

Mercedes w220 represents the fourth generation of Mercedes-Benz S-class cars which were produced in 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 in various additions S280, S320, S350, S430, S500, S600, S55 AMG, S63 AMG, S65 AMG, S320 CDI, S400 CDI. During this time, the model has been restyled. In our article you will find a description of the fuses and relays Mercedes 220 with box diagrams, photo examples and their locations. We will note the cigarette lighter fuse.

Mercedes w220

The design of the boxes and the purpose of their elements may differ from those presented and depend on the year of manufacture, the level of equipment and the region where your car was delivered.

Engine compartment

Box on the left side

One fuse and relay box is located on the left side of the engine compartment.


Photo – example

photo left side





140A Wiper heater relay (K40/6kA)
250A Supply/exhaust pump relay (K40/6kF)
315A Horizontal steering column adjustment:
• Relay 1 for longitudinal steering column adjustment (K40/6kD)
• Relay 2 for longitudinal steering column adjustment (K40/6kE)
415A Vertical steering column adjustment:
• Tilt steering relay 1 (K40/6kI)
• Relay 2 for steering angle adjustment (K40/6kJ)
540A Relay ON/OFF Wiper (K40/6kH)
67,5A Auxiliary switch heater (S4/3) / (since 09.2002 – absent)
930A With air suspension:
• Airmatic system control unit with ADS (N51)
with Active Body Level Control (ABC):
• ABC system control unit (N51/2)
1015A Washer pump (M5/1)
115/15A Cigarette lighter with front ashtray illumination (R3) / (from 09.2002 – VISC power split point X137/1) (from 09.2002 – only on Japanese models)
127.5A Dynamic locking of the seat belt band (A60) / (since 09.2002 – no longer available)
1340A Front left door control unit (N69/1)
167.5A Brake light switch (S9/1)
185A With a GSM mobile phone (D2B) (basic equipment) (code 317):
• mobile phone plug (X39/39)
If you have an MB GSM (D2B) phone (code 316):
• D2B interface for landline phone (A59)
If you have an MB GSM (D2B) telephone (code 316) with an emergency call system Tele Aid (code 347):
• Tele Aid system control unit (A35/8)
If you have an MB GSM (D2B) telephone (code 316) with an emergency call system E-Call (code 349) via the cable connector of terminal 15R (Z3/12):
• D2B interface for landline phone (A59)
• range control unit (N96)
• E-Call system control unit (A35/8) (from 09.2002 – With MB GSM (D2B) telephone (code 854):
• via connector 15R(Z3/1) of circuit 2: – frequency selection control unit (N96) – E-Call control unit (A35/8) – D2B interface for mobile phone (A59/1)
195A from 09.2002 – front left (A76) and right (A76 / 1) reversible emergency tensioners
205A Dashboard (A1) Diagnostic socket (X11/4) / (since 09.2002 – no longer available)
215A Dashboard (A1) / (since 09.2002 – no longer available)
225/1A Dashboard (A1) / (since 09.2002 – Radio (A2) control panel with COMAND system display (A40/3))
2310A Via cable connector terminal 30 KLA (Z7/21):
• KLA control panel (N22)
• circulation pump (A31/1m1)
• left double valve (A31/1y1)
• Right double valve (A31/1y2) (from 09.2002 – With TV tuner (Code 860): TV tuner (A2/10) With TV tuner (Code 860): Via connector (Z4/3) chain 30 models for Japan: – TV tuner (A2/10) – radio with CD changer (A2/16))
2410A Diagnostic socket (X11/4) / (from 09.2002 – 20A audio input control unit)
2525A since 09.2002 – Sound amplifier (A2/13)
2610A Upper control panel (N72/1) / (since 09.2002 – no longer available)

Fuse number 11 is responsible for the cigarette lighter, one more in the box in the cabin in the instrument panel.


AWiper heater relay (K40/6kA)
BRelay circuit 15 (K40/KB)
CRelay circuit 15 (K40/KC)
DLongitudinal steering column adjustment relay 1 (K40/6kD)
ELongitudinal steering column adjustment relay 2 (K40/6kE)
FPressure/exhaust pump relay (K40/6kF)
GWiper position relay 1 and 2 (K40/6kG)
HRelay ON/OFF Wiper (K40/6kH)
ITilt steering relay 1 (K40/6kI)
JTilt steering relay 2 (K40/6kJ)
KRelay for electronic engine and chassis control systems (K40/7kK)
LStarter relay (K40/7kL)
MDiesel models only: CDI relay (K40/7kM)
NAir pump relay (K40/7kN)
OAir compressor relay (K40/7kO)
PHorn relay (K40/7kP)
QRear window blind relay (K40/5kQ)
RTowing protection relay (K40/5kR)
SRelay circuit 15 (K40/5kP)
TFuel pump relay (K40/5kP)
URear defroster relay (K40/5kU)
VRelay Motronic (K40/8kV)
WAir boost relay (K40/8kW)
XIn-tank fuel pump relay (AMG only) (K40/8kX)

Box on the right side

The second fuse and relay box is located on the right side of the engine compartment.

photo 1


Diagram 1


2815A Horn relay (K40/7kP)
2920A Relay for electronic engine and chassis control systems (K40/7kK)
3020A Relay for electronic engine and chassis control systems (K40/7kK)
3140A Air pump relay (K40/7kN)
3240A Air compressor relay (K40/7kO)
3340A Heating air circulation unit (A32)
345A Traction control control unit (N47)
3515A from 09.2002 – With steering wheel heater (Code 443): Steering wheel heater (R22/4)
367.5A With Distronic (Code 219a): DTR system control unit (N63/1)
3715A Cable connector cl. 87 (Z7/5):
• control unit of the electronic module of the control lever АТ (N15/5)
• EGS system control unit (N15/3)
385A Interior boot lid button (KIT)
3940A Front right door control unit (N69/2)
4010A If available xenon. headlights (code 612b):
headlight range control unit (N71)
4120A With auxiliary heating system (code 228): via cable connector terminal 30 (brazed sleeve in wiring harness) (Z7/26):
• auxiliary heater (STH) or add. Heater (ZUH) (A6)
• radio remote control receiver STH (A6/1)
4220A • via cable plug cl. 87 (Z7/24) (until 09.2002):
4325A For diesel engines only:
• Via cable connector terminal 87 (Z7/47) (until 09.2002): – CDI control unit (N3/9) – starter relay (K40/kL) in the front right relay and fuse box (K40/7)
447.5A Diesel engines only:
• CDI control unit (N3/9)
• heating of the inlet pipeline, in the front right box of relays and fuses (K40/7)
4410A Via cable connector terminal 87D2 (Z7/48) (until 09.2002):
• CDI control unit (N3/9)
• starter relay (K40/kL) in the front right relay and fuse box (K40/7)
• electric fan-supercharger of the engine and air conditioner with built-in regulator (M4/7)
• low temperature circuit circulation pump (M44)
465A With Active Level Control (ABC):
• ABC system control unit (N51/2) With air suspension:
• Airmatic system control unit with ADS (N51)
4710A Multifunction sensor KLA (B31/1)
Fan motor in electrical protection box (M2/2)
Multifunction sensor KLA (B31/1) (until 09.2002)
relay control fan unit of the engine cooling system or AT oil (K25) via plug connector (X22/3) (until 09.2002)
Via cable electric fan circuit (Z5/1) (until 09.2002)
• multifunction sensor KLA (B31/1) (until 09.2002)
• relay control add. fan unit of the engine cooling system or oil in AT (K25) via plug connector (X22/3) (up to 09.2002)
• fan electric motor in a protective box for electrical equipment ( M2/2) (until 09.2002)
487.5A Blower fan control unit (N65/2) / (since 09.2002 – no longer available)
487.5A Electric fan-supercharger for engine and air conditioning with built-in regulator (M4/7) / (from 09.2002 – absent)
4915A Via cable connector on protected terminal 15 (Z3/29):
• ignition coils (T1/1) – (T1/8)
• radio interference suppression capacitor (C4), for Japan and USA

Additional box

Another additional box is installed under the hood on the right side.


location additional box Mercedes w220


  • V – Motronic system relay
  • W – Charge air relay
  • X – Fuel module relay in the tank (fuel pump relay)
  • 87 – 20A Motronic (K40/8kV), M275/M113 E55 AMG
  • 88 – 20A Motronic (K40/8kV), M275/M113 E55 AMG
  • 89 – Reserve
  • 90 – 10A Charge air relay (K40/8kW), M275/M113 E55 AMG
  • 91 – Reserve

Passenger compartment

Box in the dashboard

In the instrument panel on the right side, behind a protective cover, there is a fuse box.

photo of fuse box in w220


Diagram 2


  1. 7.5A Steering column control unit, Engine control unit, EIS control unit, Alarm clock
  2. 5A Instrument panel
  3. 10A Top control panel module
  4. 10A Diagnostic Connector (DLC)
  5. 10A Climate control, Air conditioning control unit
  6. 10A Center console
  7. 5A Diagnostic connector (DLC)
  8. 5A Instrument panel
  9. 15A Cigarette lighter fuse (front), Ashtray light

The fuse number 9 at 15A is responsible for the operation of the cigarette lighter.

Box under rear seat

Under the rear passenger seat is another box with fuses and relays.

location 3


Diagram 3 Mercedes w220


110A Rear window blind relay
25A Slip sensor
330A Fuel pump relay
Auxiliary relay, fuel pump
450A Heated rear window relay
510A Trailer control unit
625A Trailer connector
730A Trailer control unit
825A Closing the luggage compartment
Luggage compartment open relay
97.5A keyless go control unit
1030A Control unit (for taxi)
1215A Voice control unit
Hands free telephone
1320A Pneumatic System Equipment (PSE)
147.5A Telephone
157.5A Multifunctional control box
Antenna amplifier
1725A Sound Amplifier
1825A Power rear seats
1915A Rear air conditioner
coolant circulation pump
2015A Rear air conditioner
2110A Tire pressure monitoring control unit
2225A Seat belt pretensioner front left
2340A Door control unit, rear left
2425A Seat belt pretensioner front right
2540A Door control unit, rear right
2610A Parktronic system
2715A Refrigerator (in the back of the rear seat)
2840A Upper console (in the ceiling)
R1Rear blind relay
R2Slip sensor relay
R3Terminal 15 relay
R4Fuel pump relay
Auxiliary relay, fuel pump
R5Heated rear window relay


That’s all. And if you have something to add – write in the comments.

Comments 5

  • Is there a fuse in the 2004 S500 that controls the driver seat memory function?

  • Hi Where is the fuse for the sun roof on s class w220 2004 model as my roof does not open your Cooperation would be much appreciated.


  • looking for the fuse that controls the license plate bulbs. I did change the bulbs

  • i can’t find any box in the Passenger compartment (Box in the dashboard). it is empty. Any idea where to find it?

  • How to check c220 starting system especially wiring diagram

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