Component Description

Headlamps

Component Description

Headlamp Assembly

The headlamp assembly has an integrated solenoid activated shutter which changes the headlamp beam pattern when activated. The solenoid and shutter are not serviceable separately from the headlamp assembly. The headlamp assembly is provided power on independent circuits for the low beams and the high beams.

On vehicles equipped with HID (High Intensity Discharge) headlamps, a ballast is located within each headlamp assembly.

Lamp Assembly Condensation

Exterior lamps are vented to accommodate normal changes in pressure. Condensation can be a natural by-product of this design. When moist air enters the lamp assembly through the vents, there is a possibility that condensation can occur if the temperature is cold. When normal condensation occurs, a thin mist forms on the interior of the lens. The thin mist eventually clears and exits through the vents during normal operation. The amount of time it takes to clear the lens of acceptable mist varies with ambient humidity and lamp types. Normal condensation clears from any lamp in 48 hours under dry conditions.

Do not replace a lamp assembly with acceptable levels of condensation such as:

- presence of thin mist (no streaks, drip marks or droplets are present)

- fine mist covers less than 50% of the lens

Examples of unacceptable moisture (usually caused by a lamp housing leak):

- water puddling inside the lamp

- large water droplets, drip marks or streaks present on the interior of the lens

Ballast

There is a ballast located within each headlamp assembly. They are provided power at all times. The ballasts provide high voltage to the HID (High Intensity Discharge) bulbs when a voltage signal is detected from the BCM (Body Control Module).

Front Lighting Control Module (FLM)

The FLM (Front Lighting Control Module) monitors the headlamp switch (integrated into the FLM (Front Lighting Control Module). When the FLM (Front Lighting Control Module) detects the headlamp switch is in the HEADLAMP ON position (or a fault with the headlamp switch), it sends a message over the communication network to the BCM (Body Control Module), indicating the headlamp switch position or a fault with the headlamp switch input.