Mercedes-Benz W212 E-Class LED Headlight Driver Module Control Unit A2228700789 - Used Original Parts

Quick Answer

This module is the right fix when one LED headlight on a W212 E-Class flickers, dims, cuts out or throws a headlamp warning, and the LED elements and wiring have already been checked and found healthy. A tested used original unit makes sense in Malaysia because the driver electronics are the heat-stressed part of the lamp, and a Genuine module that has already been bench-proven avoids the high cost of a new dealer part. It also keeps the exact factory output and communication behaviour that aftermarket substitutes often fail to match.

Diagnosis and Common Symptoms

The LED driver module sits inside or behind the headlamp assembly. It converts vehicle voltage into the regulated current the LED array needs, and it talks to the car over the data bus. In Malaysia's heat, humidity and stop-and-go traffic, the power electronics go through constant thermal cycling. Solder joints, capacitors and driver stages are the usual failure points, not the LEDs themselves.

Typical symptoms on a W212 with LED headlamps:

• One headlight does not turn on, while the other works normally.
• Headlight flickers, pulses or dims after warming up, then recovers when cold.
• Instrument cluster message such as "Headlamp malfunction" or a left/right LED lamp fault warning.
• Daytime running light or low beam works but high beam or cornering function is missing.
• Headlight cuts out in heavy rain or after a car wash (check for moisture inside the lamp housing first).
• Fault memory entries for internal control unit failure, missing communication, or LED output under/over current on the affected headlamp.

Before condemning the module, a proper diagnosis should include:

1. Scan the headlamp and front SAM fault memory with a Mercedes-capable tool (XENTRY or equivalent).
2. Check supply voltage and ground at the lamp connector.
3. Inspect the connector for heat damage, corrosion or water ingress.
4. Swap the module side to side, if the part numbers match, to see whether the fault follows the unit.
5. Confirm the LED array is not the cause before replacing the driver.

If the fault follows the module, or the output is unstable on the bench, a replacement driver module is the correct repair.

Introduction

This is a Genuine Used Mercedes-Benz LED headlight driver module control unit for the W212 E-Class, removed from a donor car and tested before listing. Every unit is checked for stable output and normal operation, so you are not gambling on an unknown part. As a Genuine factory component, it keeps the original electrical characteristics and bus communication that the car expects. It is a practical, cost-sensible route for restoring full headlight function without paying for a new part.

Product Details

• Brand: Mercedes-Benz

• Model Compatibility: W212 E-Class (LED headlight equipped variants)

• Part Name: LED Headlight Driver Module Control Unit, Part No. A2228700789

• Condition: Genuine Used (Tested Working)

• Notes: Match the part number printed on the module label before purchase, as W212 headlamp electronics differ by lamp type and production period. Check the connector for heat marks or corrosion and fix any moisture ingress in the lamp housing first, or the replacement may fail again. After installation, a fault memory clear is required, and a XENTRY check for coding or component matching is recommended. Headlight aim should be verified after fitting.