Ranger 4WD V6-4.0L (2009)
Information Bus: Initial Inspection and Diagnostic Overview
Special Tools Used With Diagnostics
Communications Network
Principles of Operation
Communications Network
Principles of Operation
NOTE: The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).
Vehicle communication utilizes both the medium and high speed Controller Area Network (CAN) communications. CAN is a method for transferring
data among distributed electronic modules via a serial data bus.
The vehicle is equipped with 3 module communication networks:
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ISO 9141
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Medium Speed Controller Area Network (MS-CAN)
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High Speed Controller Area Network (HS-CAN)
ISO 9141 Communications Network
The ISO 9141 communications network is a single wire network. The ISO 9141 communications network does not permit intermodule communication.
When the scan tool communicates to modules on the ISO 9141 communication network, the scan tool must request all information; the modules cannot
initiate communications.
The following fault chart describes the specific ISO 9141 network failures and their resulting symptom:
