F 550 4WD Super Duty V10-6.8L (2009)
Diagrams/Diagrams By Number
Refer to Wiring Diagram Set 14, Module Communications Network for schematic and connector information. See: Diagrams/Electrical
Diagrams/Diagrams By Number
Normal Operation
The Smart Junction Box (SJB) communicates with the scan tool through the Medium Speed Controller Area Network (MS-CAN). Circuits VDB06
(GY/OG) (MS-CAN +) and VDB07 (VT/OG) (MS-CAN -) provide the network connection to the SJB. Voltage for the SJB is provided directly from the
internal SJB busbar through SJB fuse 5 (10A). Ground is provided by circuit GD179 (BK).
This pinpoint test is intended to diagnose the following:
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Fuse
-
Wiring, terminals or connectors
-
SJB
PINPOINT TEST H: THE SJB DOES NOT RESPOND TO THE SCAN TOOL
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the
connector.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings.
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H1 CHECK THE SJB FUSE FOR VOLTAGE
-
Ignition OFF.
-
Measure the voltage between the back of the SJB fuse 5 (10A) terminals (both sides) and ground.
-
Are the voltages greater than 10 volts?
Yes
GO to H2.
No
VERIFY the SJB fuse 5 (10A) is OK. If OK, REPAIR the circuit. CLEAR the DTCs. REPEAT the network test with the scan tool.
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H2 CHECK THE SJB GROUND CIRCUIT FOR AN OPEN
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Disconnect: Negative Battery Cable.
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Disconnect: SJB C2280d.
-
Measure the resistance between the SJB, harness side and ground as follows:
