Mercedes Seat Occupancy Installation

Mercedes Seat Occupancy Emulators - Installation

1. Turn the ignition off.

2. Under the passenger side seat find the seat occupancy sensor connector.

Seat occupancy sensor wires colours in different versions:

  • white, red, brown (the most common three-wired mat)
  • black, black (two-wired mat)
  • blue, brown, black (in some newer models)
  • white, red, brown, green (in some American US version models)
There are different types of plugs in different models, which is why we present pictures from different Mercedes models in the next part of the instructions.
 
3. If the emulator is ended with a connector, just disconnect the seat mat plug and plug in the emulator instead.
* Before connecting the plug, make sure that the order of the wires in the emulator plug is the same as the order of the wires in the seat mat plug. Rarely, may it happen that the order of the wires in the plug is different – in this case you need to change the order of the wires in the emulator plug to the same as in the original seat mat plug.
 
If the emulator is not ended with a connector, it is needed to replace seat mat wires with the emulator wires (remove wires from the plug under the seat and put the emulator wires instead in the same color order) – white for white, red for red, brown for brown.
 
In case the seat mat has wires blue, brown, black, the scheme is as below:
Brown – brown – „GND”
Black – red – „+12V”
Blue – white – signal
 
If the emulator is not ended with plug or terminals, it is needed to use special clamp connectors or solder wires.
 
4. If a car if equipped with the unfastened seat belt warning system, install the seat belt emulator as well.
 
5. Reset the fault code using proper diagnostic software.

How to disconnect it, it's not removable...

Before you go crazy about one of the most common problems – if you have one of the many Mercedes models that has a large yellow connector (including W204, W205, W212, W213, W176, W246, W166 and more) and you can’t disconnect the plugs from this connector in order to connect the emulator, in the video below we present our method:

Click on selected model to scroll to the photos of the seat mat plug:

A-Class:
W168 1997-2004
W169 2004+(two-wired mat)
W169 2004+ (three-wired mat)
W176 (three-wired mat)

B-Class:
W245 2004+ (two-wired mat)
W245 2004+ (three-wired mat)
W246 (three-wired mat)

C-Class:
W202 1997-2001
W203 2000-2004/6
W203 2004/6-2007
W204 2007-2014 (three-wired mat)

CLK-Class:
W208 1997-2003
W209 2002-2003/4
W209 2006-2009

ML-Class:
W163 1998-2005
W164 2005-2011
W166 (three-wired mat)

S-Class:
W220 1998-2005
W221 2005-2013

E-Class:
W210 1995-2003
W211 2002-2003
W211 2003/4-2009
W212 S212 C207 A207 2009-2016
W213

R-Class:
R251 2005-2013

SLK-Class:
R171 2004-2011

Vito / Viano:
W638 1995-2003
W639 2003-2014

A-Class W168

Click on the picture to enlarge

Above, we present pictures of a classic three-wire mat in A-Class.

Sometimes in W168 it may happen that there are five wires in the plug. Such a case is presented in the pictures below:

The emulator should be connected to three wires (white, red, brown). Two black wires leave unchanged.

View of the connector after opening. At this point, you can hear the squealing, which will disappear after closing the connector.

It is best to connect the emulator outside of the presented connector. For this purpose, cut the mat wires (white, red, brown) and connect the emulator towards the car installation by soldering wires or using little clamp connectors.
Thanks to the fact that the plug visible in the picture stays connected, the two black wires remain connected without any changes.

A-Class W169 and B-Class W245 (two-wired mat)

Click on the picture to enlarge

A-Class W169 and B-Class W245 (three-wired mat)
Connect the emulator to this part of connection. Wires colors on the side of car installation may be different. Wires colors on the side of seat mat: brown, white, red.
A-Class W176

The emulator supplied by us has wires in the following colors: white, red, brown.
3 wired seat mat in W176 usually has wires: blue, brown, black.
This information is not important if the emulator is equipped with a plug – just unplug the mat and connect the emulator plug.

  • If the seat mat on your car has 2 wires, don’t try to connect 3-wired emulator. As it is written in the item description in the listing, it doesn’t work with 2-wired version.
Emulator plug and wires
Seat mat plug and wires

To connect the emulator which is ended with terminals (not plug), replace the wires in the plug accordingly to the diagram below:

Brown – brown – „GND”
Black – red – „+12V”
Blue – white – signal

Watch our short installation video - it looks very similar as in W212:

B-Class W246 (three-wired mat)

The emulator supplied by us has wires in the following colors: white, red, brown.
The seat mat in W246 usually has wires in the following colors: blue, brown, black.
This information is not important if the emulator is equipped with a plug – just unplug the mat and connect the emulator plug.

Emulator plug and wires
Seat mat plug and wires

To connect the emulator which is ended with terminals (not plug), replace the wires in the plug accordingly to the diagram below:

Brown – brown – „GND”
Black – red – „+12V”
Blue – white – signal

Connected emulator

Watch our short installation video:

C-Class W202
C-Class W203 2000-2004/6 mat connector 3 pin
AND CLK-CLASS W209 2002-2003/4

Below we present the connection of the latest version of the emulator – 2in1. The seat mat and seat belt emulator are put in one enclosure which is easier to hide under the seat. The seat mat emulator plug was connected in place of the mat, the seat belt emulator plug – in place of the seat belt buckle.

Click on the photo to enlarge
C-Class W203 2004/6-2007 mat connector 4 pin
and CLK-Class W209 2006-2009

Watch our short installation video:

The view from the front of the seat. Mat plug on the left, seat belt plug on the right.
Connected emulators
C-Class W204 (three-wired mat)
and E-Class W212 (three-wired mat)

In W204 and W212, the three-wire mat has two color versions of wires, as shown in the pictures below:

White, red, brown
Blue, brown, black
View from the back of the passenger seat. The first plug on the left is the mat plug.
The first plug on the right is the seat belt buckle plug.

Watch our short installation video:

CLK-Class W208

Click on the picture to enlarge

ML-Class W163

Watch our short installation video:

S-Class W220
View from the back of the seat. The first plug from the left is the seat belt buckle plug, the second from the left is the seat mat plug (wires: white, red, brown).
S-Class W221
View from the back of the passenger seat. The first plug on the left is the mat plug.
The first plug on the right is the seat belt buckle plug.
E-Class W210
The first plug on the left (yellow) is the mat plug. On the other side of the connector (not visible in the picture) the colors of the mat wires in this plug are: brown, white, red.
E-Class W211 2002-2003
3 pin mat connector - wires: brown, white, red. View from the front of the seat
E-Class W211 2003/4-2009
View from the back of the passenger seat. The first plug on the left is the mat plug.
The first plug on the right is the seat belt buckle plug.

Watch our short installation video:

E-Class W213
ML-Class W164 AND R-Class R251
View from the back of the seat. The first yellow plug on the left is the mat plug
View from the front of the seat - different wires colors
Seat belt buckle plug which is placed on the back side of the seat. Wires: yellow, blue
ML W166 (3 wired mat)

In ML W166, the three-wired mat may have two color versions of wires, as shown in the pictures below:

White, red, brown
Blue, brown, black
View from the back of the passenger seat. The first plug on the left is the mat plug.
The first plug on the right is the seat belt buckle plug.

Watch our short installation video - W166 looks similar to W212:

SLK-Class R171

If you bought emulator ended with a plug, before connecting it, check if there is exactly the same color order of wires in the seat mat plug and in the emulator plug. Sometimes the wires order in the plug in the car was different, in this case the wiring sequence should also be changed in the emulator plug before connecting.

Vito W638
Viano W639
Seat mat plug
Seat mat plug
Mat connection disconnected
Emulators connected
The newest version of the emulator (2in1) connected