Crown Victoria V8-4.6L CNG SOHC VIN 9 (1999)
License Plate Lamp: Initial Inspection and Diagnostic Overview
Inspection and Verification (Start Testing Here)
1. Verify the customer concern by operating the system.
2. Visually inspect for obvious signs of mechanical and electrical damage.
VISUAL INSPECTION CHART
Mechanical
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Headlamp switch
Electrical
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Blown Central Junction Box (CJB) Fuse 4 (15 A)
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Damaged wiring harness
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Loose or corroded connection
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Damaged parking, rear or license bulb(s)
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Damaged Lighting Control Module (LCM)
3. If the inspection reveals obvious concern(s) that can be readily identified, repair as required.
4. If the concern remains after the inspection, connect the New Generation STAR (NGS) Tester to the Data Link Connector (DLC) located beneath
the instrument panel and select the vehicle to be tested from the NGS menu. If the NGS does not communicate with the vehicle:
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check that the program card is properly installed.
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check the connections to the vehicle.
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check the ignition switch position.
5. If the NGS still does not communicate with the vehicle, refer to the NGS Tester manual.
6. Carry out the DATA LINK DIAGNOSTIC TEST. If the NGS responds with:
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CKT914, CKT915 or CKT7O = ALL ECUS NO RESP/NOT EQUIP, refer to Information Bus.
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NO RESP/NOT EQUIP for LCM, go to Pinpoint Test A. See: Headlamp/Testing and Inspection/Component Tests and General
Diagnostics/With Manual Headlamps/Pinpoint Tests/A No Communication With the Lighting Control Module
^
SYSTEM PASSED, retrieve and record the continuous Diagnostic Trouble Codes (DTCs), erase the continuous DTCs and carry out self-test
diagnostics for the LCM.
7. If the DTCs retrieved are related to the concern, go to the LCM Diagnostic Trouble Code Index to continue diagnostics. See: Diagnostic Trouble
Code Descriptions/LCM Diagnostic Trouble Code Index
8. If no DTCs related to the concern are retrieved, proceed to Symptom Chart to continue diagnostics. See: Symptom Related Diagnostic Procedures
Principles of Operation (How Does It Work?)
The license lamps have replaceable miniature bulbs and are provided power through the Lighting Control Module (LCM) and interconnected wiring
with the headlamp switch in the PARK, HEAD, or AUTOLAMP positions.