Ranger 4WD V6-4.0L (2009)
Information Bus: Description and Operation
Communications Network
NOTE: The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).
Vehicle communication utilizes both ISO 9141 and Controller Area Network (CAN) communications. ISO 9141 is used for diagnostic use only, and
CAN is used for many modules to communicate with each other on a common network. CAN in-vehicle networking, is a method for transferring data
among distributed electronic modules via a serial data bus. Without serial networking, intermodule communication requires dedicated, point to point
wiring resulting in bulky, expensive, complex, and difficult to install wiring harnesses. Applying a serial data network reduces the number of wires,
combining the signals on a single network. Information is sent to individual control modules that control each function.
The vehicle has 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)
Both networks are connected to the Data Link Connector (DLC). This makes diagnosis and testing of these systems easier by allowing one scan tool to
be able to diagnose and control any module on both networks from one connector. The DLC can be found under the instrument panel.
Network Topology
ISO 9141 Network Operation
The ISO 9141 communications network is a low speed single wire network. The ISO 9141 communication network is used only by the ABS module.
Medium Speed Controller Area Network (MS-CAN) Operation
The MS-CAN communicates using bussed messages. The MS-CAN uses an unshielded twisted pair cable, data bus (+) and data bus (-) circuits. In
addition to scan tool communication, this network allows sharing of information between all modules on the network.
The MS-CAN is a medium speed communication network used for the following modules: