MB Medic Mercedes-Benz Repair Guides, Service, How To DIY
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In this guide (5 sections)
When the headlight bulb in your Mercedes-Benz burns out, you need to replace it with the correct bulb type and wattage rating recommended by the manufacturer. Changing a burned-out bulb on your car is easy. Low beam and high beam bulbs dim and fail as they age. Replace the bulb on both sides at the same time rather than the one that failed. The two headlights then match in brightness and color, and since both bulbs have the same hours on them, the survivor is usually not far behind.
IMPORTANT: Avoid touching the light bulb glass with your hands.
You could also upgrade to HID bulbs. We recommend using an aftermarket HID kit for the same bulb size, possibly an Error Free Kit. Here are a few listings of Error Free HID Conversion Kits that fit Mercedes-Benz cars on Amazon.
Before you buy one, understand what a conversion kit does and does not give you. The factory xenon W220 uses a projector lens built around an arc source, with headlamp leveling. Putting an arc capsule into a reflector housing designed around a halogen filament puts the light where the reflector was never shaped to send it, so what you mostly gain is glare for oncoming drivers rather than usable distance down the road. NHTSA has taken the position that an HID conversion set cannot meet the photometry requirements of FMVSS 108 in a halogen headlamp, which is why the kits cannot lawfully be sold for that purpose in the United States, and a shop that installs one runs into the federal rule against making safety equipment inoperative. As an owner you are most likely to meet this at state inspection, and those rules vary by state. If you want xenon light output on a W220, the route that actually works is a complete factory bi-xenon headlight assembly with its igniters and ballasts, not a kit in the halogen housing.
First, check which headlights your car has
The W220 and W215 were sold with halogen headlights and with gas discharge, or xenon, headlights, so the bulb in this guide is not the bulb in every one of these cars. Confirm which system you have before you buy anything.
- Halogen cars use an H7 55W bulb, and the same H7 55W serves the high beam.
- Xenon cars use a D2S 35W gas discharge capsule for the low beam. An H7 will not fit it. On the earlier xenon setup the low beam is xenon while the high beam is still a halogen H7, so on that car a dead high beam is an H7 job even though the low beam beside it is not.
- Facelift bi-xenon cars use one D2S for both beams, with a motor that swings a shield clear for high beam. There is no separate high beam bulb to replace.
The quickest way to tell them apart is the bulb itself. An H7 is a small glass envelope with a visible filament on a flat plastic base with a wire retaining tab. A D2S sits in a molded carrier and plugs into an igniter block rather than a simple two wire connector.
SAFETY: the igniter fires a D2S with a high voltage strike pulse. Switch the headlights off and switch the car off before you unplug anything on a xenon headlight, and never pull a D2S with the lights live. If a xenon lamp flickers, has gone pink, or lights and then quits, the cause is an aging capsule, a failing igniter, or a failing ballast, and a new capsule will not fix the last two.
WHAT YOU NEED
- H7 55W Low Beam Bulb Buy on Amazon
HOW TO CHANGE THE LOW BEAM HEADLIGHT BULB
There is limited space behind the headlight, so it helps to know the whole sequence before you start.
- Open the hood by pulling the hood release under the dash on the driver’s side.
- Pull the hood catch and lift the hood.
- Locate the back of the headlight.
S430 S500 Headlight - Remove the plastic cover from the back of the headlight assembly. Press the two plastic tabs together to remove the headlamp cover.
- Remove the electrical connector from the low-beam halogen-type light bulb.
- Remove the light bulb from the socket. Install the new bulb without touching its glass. Make sure it seats fully in the recess, because a bulb that is not seated squarely will aim wrong no matter how good it is.
- Reinstall the electrical connector and the headlight cover in reverse order.
NOTE: The headlight bulb must fit in the headlight socket properly. The light beam will not project correctly if the bulb doesn’t work properly in the socket. You can verify this by turning on the light and looking at the headlights from 20 feet away. Both headlights should be the same brightness.
How to change the high beam bulb
On a halogen W220 or W215 the high beam is the same H7 55W bulb as the low beam, behind the same cover, in the socket next to it. The handling rules do not change: keep your fingers off the glass, and do the other side at the same time.
On an early xenon car the high beam is halogen, so this is an H7 job even though the low beam next to it is a D2S. On a facelift bi-xenon car there is no high beam bulb at all, because the one D2S covers both beams. If the high beam does not come on there, the fault is in the shield mechanism, the igniter, or the ballast, and no bulb will fix it.
If the bulb out warning stays on after a good bulb
The warning on these cars is not driven by the bulb itself. A control module watches the current through each lamp output and reports a lamp it cannot see. So once a known good bulb is seated fully and the beam looks right, a message that will not clear is pointing at the socket contacts, the wiring to that lamp, or the module output rather than at the bulb you just bought.
Reading the stored fault is what separates those, and on a xenon car it is what separates a tired capsule from an igniter or ballast fault before you spend money on a second capsule. A full system scanner will read and clear the lighting faults these modules store, which a generic code reader will not reach.
Applicable Models: S430 S500 S55 CL500 CL600 Chassis: W220 W215 Years: 1998 1999 2000 2001 2002 2003 2004 2005 2006
Before you buy parts, scan every control module, not just the engine. It shows the root fault behind the warning lights and tells you whether the problem is still active. See how to do a full health check.
