Use Of Wiring Diagrams - OV00.01-P-1901-03FCA

Model 253 (except 253.99) 

as of model year 2020 

Model 253.99 

as of model year 2019 

with code 9O1 (Fuel cell pre-installation) 

Wiring diagrams 

The wiring diagrams are assigned to the familiar function groups 00-91.

The circuit diagrams are filed according to PE number in each function group, e.g.:

• PE06.20-P-2101FCA
• PE06.20-P-2102FCA

The location of ground points, end sleeves and electrical connectors is shown on the following 3 documents:

• Electrical connectors GF00.19-P-1005FCA
• Ground points GF00.19-P-2002FCA
• Connector sleeves >GF00.19-P-3005FCA

The assignment of components can be obtained from the wiring diagrams specified in the list of contents.

All electrical components are sorted alphabetically and listed according to the abbreviations in the "Search aid for all electrical components" OV00.01-P-1909FCA . A reference is made to the wiring diagrams in which the relevant component is explained completely.

Variants of a component or the subdivision of a component into several wiring diagrams are stated in the third column.

Wiring diagram number 

Courtesy of MERCEDES-BENZ USA

Kinds of wiring diagrams 

The wiring diagrams are prepared as function schematics, function diagrams, control unit diagrams or connector sleeve wiring diagrams, ground wiring diagrams and connector wiring diagrams.

• Function schematics

  The control units and electrical components required for the function are shown as symbols. The functional connections are realized by direct lines or by the data bus.

• Function diagrams

  All the parts of components that are relevant to a function are explained in the wiring diagram.

• Control unit diagrams

  Control units are represented complete with all connected components. Control units with many connections can be subdivided into several wiring diagrams.

• Solder point wiring diagrams, ground wiring diagrams and connector wiring diagrams

  Solder points, ground points and electrical connections, which are not shown completely in any control unit diagram, are shown here complete with all connected components.

Function schematic 

Courtesy of MERCEDES-BENZ USA

CAN bus presentation 

Courtesy of MERCEDES-BENZ USA

LIN bus presentation 

Courtesy of MERCEDES-BENZ USA

MOST bus presentation 

Courtesy of MERCEDES-BENZ USA

Line cross-sections and line colors on the vehicle may differ from the illustration in the wiring diagrams.

Wire Identification 

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Wire colors: 

BK = Black

BN = Brown

BU = Blue

GN = Green

GY = Gray

OG = Orange

PK = Pink

RD = Red

TR = Transparent

VT = Violet

WH = White

YE = Yellow

The symbol refers to further wiring diagrams.

Fuse blocks 

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Components and switches 

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Variants 

The wiring diagrams can contain variants that are framed to identify them and provided with an abbreviation "U..." or "Code or are marked with a time limitation or a vehicle identification end number.

The variants identified by the abbreviation "U..." or "Code..." are listed in the legends.

The vehicle identification end numbers or time production data stated apply to the market launch of standard production.

Preproduction vehicles can have a lower vehicle identification end number or an earlier production breakpoint.

In case of changes that come up after the market launch of standard production, the variants can be designated with 1 and 2.

Logical combinations of variants are represented as follows:

• »And/or« combination

  Validity elements are presented one below the other; the variant is valid if at least one of the validity elements applies.

• »And« combination

  Validity elements are presented indented one below the other; the variant is valid if all the validity elements apply.

Courtesy of MERCEDES-BENZ USA

Signal and terminal designations 

The signal and circuit designations used are explained in the section "Abbreviations of signal and circuit designations for wiring diagrams" OV00.01-P-1001-28FCA .

Special features in WIS presentation 

In WIS it is possible to select certain areas in the wiring diagram and consequently to switch to other documents or wiring diagrams.

• Selection of electrical connectors → Document: Location of electrical connectors
• Selection of ground points → Document: Location of ground points
• Selection of Z end sleeves → Document: Location of end sleeves
• Selection of PE hands → Reference to further wiring diagrams
• Selection of component designations A and N → Document:

  Abbreviations of signal and circuit designations for wiring diagrams

• Selection of component designation A0 → Document: Use of wiring diagrams