Most of connector symbols in wiring diagrams are shown from the terminal side.
For description and how to disconnect, refer to PG section, “Description”, “HARNESS CONNECTOR”.

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

Sample/wiring diagram -example-NISSAN vehicle immobilizer system
The NISSAN Vehicle Immobilizer system will not
allow the engine to start without the use of the
registered key.
If the engine fails to start using a registered key
(for example, when interference is caused by
another registered key, an automated toll road
device or automatic payment device o ...
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”,
used along
with a front seat belt, helps to reduce the risk or severity of injury to the
driver and front passenger for certain
types of collision. Information necessary to service the system ...
A-bag branch line circuit
Diagnosis procedure
Warning:
Always observe the following items for preventing accidental
activation.
Before servicing, turn ignition switch off, disconnect battery
negative terminal, and wait 3 minutes
or more. (To discharge backup capacitor.)
Never use unspecified tester or other me ...