Diagnostic Communication Network

Diagnostic Communication Network Components

The diagnostic communication network:
- consists of a single wire, Circuit 70 (LB/W).
- provides a common link for communication to an off-board tester through the Data Link Connector (DLC) located under the instrument panel to the right of the steering column.
- does not allow module-to-module communications.

The micro-processor based subsystems included on this network are:
- supplemental air bag system
- keyless entry
- power locks and windows
- interior lighting control
- warning indicator control

Fault Tolerance
The diagnostic communication network will fail if any of the following occur:
- Circuit 70 (LB/W) shorted to ground.
- Circuit 70 (LB/W) shorted to battery positive voltage (B+).
- the module loses power or ground supply.
- a module failure shorts the communication network internally.

Purpose
The information is designed to diagnose any diagnostic communication network concerns. These concerns may:
- affect normal functional operations of the vehicle.
- be directly related to customer concerns.
- be undetectable except during diagnostics.

To properly diagnose a network concern, follow the diagnostic procedure in the order presented.

Module Identification
Modules included on this diagnostic communication network include:

Electronic Crash Sensor
- located behind the instrument panel to the right of the steering column.
- a failed ECS may cause a no communication condition on the diagnostic communication network.
- if communication to the electronic crash sensor fails, refer to Safety Belts for No Communication testing. Seat Belt Systems

Driver Door Module
- located behind driver front door trim panel.
- if communication to the driver door module fails, refer to Windows and Glass for No Communication testing. Windows and Glass

Lighting Control Module
- located behind the instrument panel to the right of the steering column.
- if communication to the lighting control module fails, refer to Lighting and Horns for No Communication testing. Lighting and Horns