Symptom Chart

WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM CHART

Condition	Possible Sources	Action
No communication with the lighting control module (LCM)	Circuitry LCM	REFER to MULTIFUNCTION ELECTRONIC MODULES .
Low beams flash on and turn off	Headlamp bulbs	INSTALL new headlamp bulbs according to Ford specifications.
Both headlamps are inoperative	LCM	CHECK the operation of the low beams and high beams. If the low beams or high beams operate correctly, GO to SYMPTOM CHART for correct diagnosis. If the low beams and the high beams are inoperative, INSTALL a new LCM. REFER to MULTIFUNCTION ELECTRONIC MODULES . TEST the system for normal operation.
NOTE: Due to varying wattage ratings and resulting current draw, certain aftermarket headlamp bulbs may cause the LCM to shut down the short circuit protection, resulting in the low beams becoming inoperative. Verify that the bulbs meet Ford specifications. The low beams are inoperative	LCM	CHECK the LCM to make sure it is configured correctly. VERIFY the headlamp bulbs meet Ford specifications. If the low beams do not meet Ford specifications, INSTALL new headlamp bulbs according to Ford specifications. TEST the system for normal operation If the low beams meet Ford specifications, INSTALL a new LCM. REFER to MULTIFUNCTION ELECTRONIC MODULES . TEST the system for normal operation.
The high beams are inoperative	Fuse Circuitry Multifunction switch LCM	GO to PINPOINT TEST A .
One low beam headlamp is inoperative	Fuse Circuitry LCM	GO to PINPOINT TEST B .
One high beam headlamp is inoperative	Circuitry LCM	GO to PINPOINT TEST C .
The headlamps are on continuously	Circuitry Multifunction switch Headlamp switch LCM	GO to PINPOINT TEST D .
The flash-to-pass feature is inoperative	Circuitry Multifunction switch LCM	GO to PINPOINT TEST E .