How to Read Wiring Diagrams

Description (Item: 1 - 19):

Description (Item: 20 - 32):

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 and followed by the direction mark.
- Connector symbols shown from the harness side are enclosed by a double line and followed by the direction mark.
- Certain systems and components, especially those related to OBD, may use a new style slide-locking type harness connector.




- Male and female terminals

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




SWITCH POSITIONS
Switches are shown in wiring diagrams as if the vehicle is in the "normal" condition.

A vehicle is in the "normal" condition when:
- ignition switch is "OFF",
- doors, hood and trunk lid/back door are closed,
- pedals are not depressed, and
- parking brake is released.











WIRING DIAGRAMS - EXAMPLE




DETECTABLE LINES 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 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.




MULTIPLE SWITCH
The continuity of multiple switch is described in two ways.
- The switch chart is used in schematic diagrams.
- The switch diagram is used in wiring diagrams.