Airbag control unit with part number A1679009428

What is the function of the airbag control unit A1679009428?

The part number A1679009428 refers to an original Mercedes-Benz OEM airbag/SRS control unit. Its primary function is to monitor all components of the passive safety system, process crash sensor data, and precisely activate restraint systems such as airbags and seatbelt pretensioners in the event of a collision.

This control unit serves as the central computer for the entire Supplemental Restraint System (SRS). It continuously communicates with various sensors distributed throughout the vehicle to detect collisions and assess their severity.

Based on these sensor inputs, the module determines within milliseconds whether and which airbags (e.g., front, side, or head airbags) and seatbelt pretensioners need to be activated to ensure optimal occupant protection.

Why does the control unit A1679009428 fail?

A common cause of failure or malfunction of the A1679009428 is the storage of crash data after an accident, which locks the device’s functionality. Additionally, defects in electronic components on the circuit board—such as faulty SMD parts or broken traces—can lead to partial or complete failure.

After a collision, even minor ones, the control unit stores a so‑called “crash event” in its internal memory. This is a safety measure that locks the device and prevents reuse until this data is professionally erased. As a result, the airbag warning light remains permanently illuminated.

Electronic faults are another frequent cause. These include damage to individual components on the board caused by voltage spikes, moisture, or material degradation due to aging. A professional diagnosis can determine whether the issue stems from data-related problems or hardware failures.

How do you recognize a defect in the A1679009428?

A defect in the A1679009428 control unit primarily manifests as a continuously or intermittently illuminated SRS or airbag warning light on the instrument cluster. Often, communication with the control unit cannot be established via the diagnostic tool, or specific, non‑erasable SRS error codes appear.

The most obvious symptom is the active airbag warning light, indicating a fault within the restraint system—often originating from the control unit itself.

During workshop diagnostics, a typical sign is that the control unit no longer responds to requests from the diagnostic equipment. If communication is possible, specific error codes usually indicate an internal device fault or stored crash data. It is crucial to document these codes before removing the unit.

In which vehicles is the A1679009428 installed?

The airbag control unit with part number A1679009428 is an original component specifically used in modern Mercedes-Benz SUV models. It is predominantly found in the GLE series, both in the standard SUV version and the coupe variant.

At Airbag24, we expertly repair the A1679009428 control unit for the following Mercedes-Benz models:

Mercedes-Benz GLE-Class V167 (from model year 2018 onward)

Mercedes-Benz GLE-Class C167 SUV Coupe (from model year 2019 onward)

How does the repair process work at Airbag24?

The repair of the A1679009428 at Airbag24 follows a professional, documented procedure. After an initial in‑vehicle diagnosis, the removed unit undergoes a comprehensive electronic analysis, repairs of hardware defects, or erasure of crash data, followed by a final functional test.

The process begins with a proper diagnosis and removal at your workshop. It is essential to read out the fault memory log and attach it to the shipment.

Upon arrival at Airbag24, the control unit undergoes an incoming inspection, including visual checks and electronic analysis of the circuit board and memory modules.

Depending on the nature of the fault, our technicians erase stored crash data or fix electronic issues by replacing defective components. Subsequently, vehicle‑specific coding is verified and restored if necessary.

A final test ensures full functionality of the repaired control unit. All repairs come with 2 years' statutory liability for defects.