How to Read Wiring Diagrams

How to Read Wiring Diagrams

CONNECTOR SYMBOLS

How To Read Wiring Diagrams: Description: Connector Symbols:

Most of connector symbols in wiring diagrams are shown from the terminal side.
^ Connector symbols shown from the terminal side are enclosed by a single line.
^ Connector symbols shown from the harness side are enclosed by a double line and followed by the direction mark

^ Male and female terminals
Connector guides for male terminals are shown in black and female terminals in white in wiring diagrams.

WIRING DIAGRAM - EXAMPLE

Sample Wiring Diagram:

Sample Wiring Diagram With Optional Splice:

EXAMPLE DIAGRAM LEGEND

How To Read Wiring Diagrams: Description:

CIRCUIT CODES AND DESCRIPTIONS

How To Read Wiring Diagrams: Cell Codes:

Use the chart to find out what each wiring diagram code stands for.

DETECTABLE AND NON-DETECTABLE LINES

How To Read Wiring Diagrams: Description: Detectable And Non Detectable Lines:

In some wiring diagrams, two kinds of lines, representing wires, with different weight are used.
^ A line with regular weight (wider line) represents a "detectable line for DTC (Diagnostic Trouble Code)". A "detectable line for DTC" is a circuit in which ECM (ECCS control module) can detect its malfunctions with the on-board diagnostic system.
^ A line with less weight (thinner line) represents a "non-detectable line for DTC". A "non-detectable line for DTC" is a circuit in which ECM cannot detect its malfunctions with the on-board diagnostic system.

SWITCH POSITIONS

Wiring diagram switches are shown with the vehicle in the following condition.
^ Ignition switch "OFF".
^ Doors, hood and trunk lid/back door closed.
^ Pedals are not depressed.
^ Parking brake is released.

MULTIPLE SWITCHES

How To Read Wiring Diagrams: Description: Multiple Switch:

The continuity of the multiple switch is identified in the switch chart in wiring diagrams.
^ The switch chart is used in schematic diagrams.
^ The switch diagram is used in wiring diagrams.

SUPER MULTIPLE JUNCTIONS (SMJ)

How To Read Wiring Diagrams: Description:

In wiring diagram, connectors consisting of terminals having terminal numbers with an alphabet (B1, D0, etc.) are SMJ connectors. If connector numbers are shown in Reference Area, these connector symbols are not shown in Connector Area.