F 250 2WD Super Duty V8-5.4L (2008)
Body Control Systems: Initial Inspection and Diagnostic Overview
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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Battery junction box (BJB) fuse 45 (30A)
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Smart junction box (SJB) fuses:
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12 (7.5A)
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20 (15A)
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Wiring, terminals or connectors
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Driver seat module (DSM)
3. If an obvious cause of an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
4. NOTE: Make sure to use the latest scan tool software release.
If the cause is not visually evident, connect the scan tool to the data link connector (DLC).
5. NOTE: The vehicle communication module (VCM) LED prove-out confirms power and ground from the DLC are provided to the VCM.
If the scan tool does not communicate with the VCM:
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Check the VCM connection to the vehicle.
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Check the scan tool connection to the VCM.
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Refer to Information Bus (Module Communications Network), No Power To The Scan Tool, to diagnose no communication with the scan tool.
6. If the scan tool does not communicate with the vehicle:
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Verify the ignition key is in the ON position.
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Verify the scan tool operation with a known good vehicle.
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Refer to Information Bus (Module Communications Network) to diagnose no response from the PCM.
7. Carry out the network test:
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If the scan tool responds with no communication for one or more modules, refer to Information Bus (Module Communications Network).
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If the network test passes, retrieve and record the continuous memory DTCs.
8. Clear the continuous DTCs and carry out the self-test diagnostics for the DSM.
9. For all DTCs, refer to the Diagnostic Trouble Code (DTC) Chart. See: Diagnostic Trouble Code Descriptions/Diagnostic Trouble Code (DTC)
Chart
10. If no DTCs related to the concern are retrieved, GO to Symptom Chart. See: Symptom Related Diagnostic Procedures/Driver Seat Module (DSM)
Principles of Operation
PRINCIPLES OF OPERATION
NOTE: The smart junction box (SJB) is also known as the generic electronic module (GEM).
The driver seat module (DSM) allows the driver to program a personalized memory seat position that can be recalled using the memory switch or a
remote keyless entry (RKE) transmitter. In addition to the position of the driver seat, the DSM also controls the position of the memory exterior mirrors
and the memory adjustable pedals. Refer to Seats for the memory seats. Refer to Mirrors for the memory mirrors. Refer to Brakes and Traction Control
for the memory adjustable pedals.
The DSM is part of the medium speed communication area network (MS-CAN), over which it receives the gearshift lever position. All other functions of
the DSM are hardwired.
Inspection and Verification
INSPECTION AND VERIFICATION
1. Verify the customer concern.
2. Visually inspect for obvious signs of electrical damage.