Welcome to your step-by-step DIY guide on how to save big by replacing your W204 C-Class (2007–2015) D1S Xenon headlight bulbs and ballast/control modules using affordable parts from AliExpress—all for approximately $16 each!

Tools & Parts You’ll Need
Item Notes
Replacement D1S bulb (~$15–$18) Pick reputable sellers with good feedback on AliExpress.
Replacement ballast/control module (~$18–$20) AliExpress offers plug-and-play modules, but double-check compatibility.
Flat-head screwdriver For dust cap and metal clip.
Clean gloves To avoid touching the bulb glass and risking premature failure.

Quick Summary – Replace in 5 Easy Steps

Prep & Safety

Park, turn off your car, and remove the key. Let HID system cool down to avoid burn risks.

Access Bulb

Open the hood. Locate and remove the dust cap on the back of the headlight housing.

Replace Bulb

Disconnect the electrical connector, push down the metal retaining clip, release, twist the old D1S bulb counterclockwise and remove. Install the new bulb by reversing the process.


Swap the Ballast Module

Locate your ballast/control module (often mounted beneath or behind the headlight). Unbolt or unclip it, disconnect the plug, install your AliExpress replacement, and reattach—ensuring it's compatible and plug-and-play.

Test & Reassemble

Power on your headlights, verify proper operation with no flickers or error messages, re-fit dust cap, and you’re done!

Why Use AliExpress Parts?

Cost-effective—most modules and bulbs can be found for ~$16 total, significantly less than dealer price.

Accessibility—plug-and-play modules mean no coding required; just bolt, plug in, and go!

DIY-friendly—simple steps you can do at home with minimal tools and no headlight removal.

Pro Tips

Always avoid touching the glass of the new D1S bulb with bare fingers—it can shorten the bulb life.

If lights flicker or fail, double-check plug fit, compatibility, and ensure the ballast is correct model for W204 (2008–15).


Some ballasts have varied part numbers—verify referencing OEM codes (e.g., 1669002800 A1669002800 A1669002800 A1669002800, 130732946815) if unsure.