E46 Headlight Replacement Parts

Xabier.M / Foter.com / CC BY-NC-ND

If you’ve owned or have seen a BMW 3-series shuttling around town, chances are it was of the E46 variety, covering model years 1999 through 2006. The E46 headlight design continued BMW’s signature pair of circular lenses, with normal driving headlamps on the outside and high beams on the inside. A turn signal was integrated into the headlight housing.E46 headlights came in several varieties. The main difference was the type of bulb used, xenon or halogen. Xenon (also known as HID) headlamps are based on the light generated from an arc of pure, superheated xenon. They give off extremely bright, white light. In contrast, halogen headlamps use interactions between a tungsten filament and halogen gas to give off light. Their light is dimmer and more yellowish.

Because of the use of a filament along with a continuous chemical reaction to generate light, halogen headlights are less reliable and have a shorter lifetime than xenon ones. While xenon or halogen lamps were included as an optional on the E46, the headlights on E46 coupes (including the M3 variant) typically run xenon while those on E46 sedans run on halogen. The xenon variety, however, come with additional components such as a ballast for dissipating excess electric power and an igniter for starting the xenon arc. These additional components are common points of failure on E46 headlights.

E46 cars model year 2002 and later are known as “facelift” variants and include a slightly sleeker headlight design. The easiest way to tell a pre-facelift headlight from a facelift headlight is that the latter will have turn signals that slant up to the sides. They will also include smoother cutouts for the bottoms of the circular headlight lenses.

A technology in these headlights that may be difficult to notice under most conditions is the auto-leveling mechanism. Sensors near the rear wheels detect the angle at which the car is tilting forward or backward, and the auto-leveling mechanism tilts the headlamps forward or back to compensate. This is to increase road visibility and to avoid blinding drivers heading in the opposite direction. If the headlights are pointing too far up or down, or tilt themselves erratically, it may be a sign of a faulty auto-leveling mechanism or auto-leveling sensor.