F 150 4WD V8-5.4L Flex Fuel (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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Central junction box (CJB) fuse(s):
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3 (7.5A)
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109 (30A)
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Wiring, terminals or connectors
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Driver seat module (DSM)
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. 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. If the DTCs retrieved are related to the concern, go to Diagnostic Trouble Code (DTC) Chart. See: Diagnostic Trouble Code Descriptions
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
The driver seat module (DSM) supports several vehicle subsystems and permits inter-module and scan tool communications.
The memory driver seat feature allows the driver to program a personalized seat position that can be recalled using the memory switches. Refer to Seats.
The adjustable pedals are also controlled by the DSM. This system permits the adjustment of the brake and accelerator pedals using the adjustable pedal
switch. Refer to Brakes and Traction Control.
Principles of Operation
PRINCIPLES OF OPERATION
The vehicle security module (VSM) controls the power door lock system. The module monitors the door lock/unlock switch inputs from the interior door
lock switches. When the module receives an unlock/lock command from any door lock control switch, the module activates the door lock actuators.
Refer to Locks.
The module also controls the following remote lock/unlock features:
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Keyless entry keypad
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Panic alarm
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Remote keyless entry (RKE) transmitter lock/unlock
