Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2003 Ford ThunderbirdFACTORY OEM SERVICE PROCEDURE
Lighting Systems Front Electronic Module (Fem) Diagnostic Trouble Code (DTC) List
LIGHTING SYSTEMS FRONT ELECTRONIC MODULE (FEM) DIAGNOSTIC TROUBLE CODE (DTC) LIST
| DTC | Description | Source | Action |
|---|---|---|---|
| B1342 | ECU Is Defective | FEM | CLEAR the DTCs. RETRIEVE the DTCs. If DTC B1342 is retrieved, INSTALL a new FEM. REFER to MODULE COMMUNICATIONS NETWORK . |
| B1499 | Lamp Turn Signal Left Circuit Failure | FEM | If inoperative, Go To PINPOINT TEST Q
. If always on, Go To PINPOINT TEST R . |
| B1501 | Lamp Turn Signal Left Circuit Short to Battery | FEM | Go To PINPOINT TEST Q . |
| B1503 | Lamp Turn Signal Right Circuit Failure | FEM | If inoperative, Go To PINPOINT TEST Q
. If always on, Go To PINPOINT TEST R . |
| B1505 | Lamp Turn Signal Right Circuit Short to Battery | FEM | Go To PINPOINT TEST Q . |
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.