Test G: No International Standards Organization (ISO) 9141 Communication Network Communication

PINPOINT TEST G: NO INTERNATIONAL STANDARDS ORGANIZATION (ISO) 9141 COMMUNICATION NETWORK COMMUNICATION

G1-G2:

G3-G7:

G8-G11:

G12-15:

G15-G18:

G19:

Normal Operation
The restraints control module (RCM), four-wheel drive (4WD) control module, smart junction box (SJB), and the anti-lock brake system (ABS) module communicate with the diagnostic tool through the ISO 9141 communication network circuit 70 (LB/WH). Check circuit 70 (LB/WH) between the networked modules and the data link connector (DLC) C251. If the ISO 9141 communication network circuit is open, communication to the module in question is not possible. If the circuit is shorted to ground or shorted to voltage, the entire network goes down and communication to all modules is not possible. If, after individual checks of each circuit leading to a module show resistance values less than 5 ohms, and no in-line connector issues are present, the data link diagnostics test must be run with the module in question disconnected. If the data link diagnostics test passes with the module in question disconnected, it is the source of the concern and should be removed and a new module installed.

Possible Causes
- ISO 9141 communication network circuit 70 (LB/WH) open, short to ground or short to voltage
- DLC C251
- RCM C2041
- 4WD control module C281a (if equipped)
- SJB C2280d
- ABS module C135
- RCM
- 4WD control module (if equipped)
- SJB
- ABS module

NOTE: The ISO 9141 network diagnostics requires depower of the air bag system when disconnecting the RCM C2041. When key ON occurs to carry out the data link diagnostic test, diagnostic trouble codes (DTCs) may be stored in both the RCM. These DTCs should be cleared when network diagnostics are completed.