Mariner 4WD L4-2.3L VIN Z (2005)
Information Bus: Testing and Inspection
Communications Network
Principles of Operation
PRINCIPLES OF OPERATION
The vehicle has 3 module communication networks: high speed and medium speed CAN network, which are comprised of unshielded twisted pair cable,
and the international standards organization (ISO) 9141 communication network, which is a single wire network. All 3 networks are connected to the
data link connector (DLC). This makes diagnosis and testing of these systems easier by allowing a diagnostic tester to be able to diagnose and control
any module on the 3 networks from the connector. The DLC can be found under the instrument panel between the steering column and the radio.
The high speed and medium speed CAN remain operational even with the severing of one of the bus wires. Communications will also continue if one of
the bus wires is shorted to ground or voltage. If any of the termination resistors are lost, communication is not possible.
The ISO 9141 communication network does not permit intermodule communication. When the diagnostic tool communicates to modules on the ISO
9141 communication network, the diagnostic tool must ask for all information; the modules cannot initiate communications.
The ISO 9141 communication network will not function if the wire is shorted to ground or battery voltage. Also, if one of the modules on the ISO 9141
communication network loses power or shorts internally, communication to that module will fail.
Inspection and Verification
INSPECTION AND VERIFICATION
1. Verify the customer concern.
2. Visually inspect for obvious signs of electrical damage.
VISUAL INSPECTION CHART
Electrical
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Smart junction box (SJB) fuse 7 (10A)
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Wiring harness
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Network connections
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Data link connector (DLC) C251
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
4. If the cause is not visually evident, connect the diagnostic tool to the data link connector and select the vehicle to be tested from the diagnostic tool
menu. If the diagnostic tool does not communicate with the vehicle:
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check that the program card is correctly installed.
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check the connections to the vehicle.
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check the ignition switch position.
5. If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool operating manual.
6. GO to Pinpoint Test PC. See: Pinpoint Tests/Pinpoint Test PC (Precheck)
Pinpoint Test PC (Precheck)
PINPOINT TEST PC: DATA LINK DIAGNOSTICS NETWORK TEST
