ISO 9141 Communication Link

ISO 9141 Communication Link:

The ISO 9141 communication link:
^ 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:
^ Anti-lock brake
^ Supplemental air bag restraints
^ Active anti-theft
^ Keyless entry
^ Windshield wiper
^ Power locks and windows
^ Power steering
^ Interior lighting control
^ Semi-automatic ride control
^ Warning indicator control

Fault Tolerance
The ISO 9141 communication link 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 ISO 9141 communication network internally.

Purpose
The information within this section is designed to diagnose ISO 9141 communication link 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 link concern, follow the diagnostic procedure in the order presented.

Module Identification
Modules included on this ISO 9141 communication link include:

Air Bag Diagnostic Monitor:
^ Located behind the instrument panel to the right of the steering column.
^ A failed air bag diagnostic monitor may cause no communication condition on ISO 9141 communication link.
^ If communication to the air bag diagnostic monitor fails, refer to Air Bags (Supplemental Restraint Systems) for No Communication testing.

Anti-Lock Brake System (ABS) Control Module:
^ Located under the battery tray in the lower left of the engine compartment.
^ A failed anti-lock brake system module may cause no communication condition on ISO 9141 communication link.
^ If communication to the anti-lock brake control module fails, refer to Antilock Brake System for No Communication testing.

Generic Electronic Module (GEM):
^ Is plugged into the fuse junction panel.
^ A failed GEM may cause a no communication condition on ISO 9141 communication link.
^ If communication to the GEM fails, refer to the affected system for No Communication testing.

Remote Anti-Theft Personality (RAP) Module:
^ Located under the instrument panel to the right of the steering column.
^ A failed RAP module may cause no communication condition on ISO 9141 communication link.
^ If communication to the RAP module fails, refer to Locks for No Communication testing.

Semi-Active Ride Control (SARC):
^ Located in the luggage compartment on the front of the RH rear wheel housing.
^ If communication to the semi-active ride control module fails, refer to Suspension for No Communication testing.