Airbag control unit with part number A2059002512

What is the function of the airbag control unit A2059002512?

The airbag control unit with part number A2059002512 is the central control module of the Supplemental Restraint System (SRS) in certain Mercedes-Benz C-Class models. Its primary task is to process signals from crash sensors and, in the event of a collision, precisely deploy the airbags and seatbelt pretensioners.

As the heart of the passive safety system, this module continuously monitors all connected components, from impact sensors to individual airbag modules. It ensures that the restraint system remains operational at all times and functions correctly in an emergency.

If there is a fault in the system—whether in a sensor or within the control unit itself—the SRS warning light on the instrument panel illuminates immediately to alert the driver.

Why does the control unit A2059002512 fail?

The most common causes of failure for the control unit A2059002512 are stored crash data following a collision that cannot be erased, as well as internal hardware defects. These electronic faults often manifest as the persistent error code B1BC7-49 ("Internal Electronic Failure"), indicating defective components on the circuit board.

After a collision—even minor accidents where the airbags did not deploy—the device stores so‑called crash data. For safety reasons, these data lock the control unit and prevent further use until they are professionally reset; simple clearing via a diagnostic tool is not sufficient.

The error code B1BC7-49 points to an internal electronic malfunction. Typically, this is not a software issue but rather a problem with physical components on the control unit’s circuit board. Similar fault patterns can also occur with related part numbers such as A2C81768406.

How do you recognize a defect in the A2059002512?

A defect in the A2059002512 control unit almost always shows up as a red airbag warning light (SRS lamp) that remains illuminated continuously or intermittently on the dashboard. During diagnostics, the error code B1BC7-49 is frequently read—a non‑erasable code indicating an internal fault.

The most noticeable sign of a problem is the activated SRS warning light, signaling that the airbag system is not functioning properly and may fail to deploy in the event of a crash.

Workshops diagnosing the issue find that the B1BC7-49 error is permanently stored. In some cases, communication with the control unit has also been lost, complicating further analysis.

Rarely, vehicle owners report additional symptoms, such as a falsely triggered fuel shut-off valve indicator or other warning lights that cannot be deactivated.

In which vehicles is the A2059002512 installed?

The airbag control unit A2059002512 is specifically designed for the Mercedes-Benz C-Class of the 205 series. At Airbag24, we repair this module for the sedan (W205), the estate (S205), and the coupé (C205) from the corresponding model years.

We offer repairs for the following models:

Mercedes-Benz C-Class Sedan (W205), model years 2014–2021

Mercedes-Benz C-Class Estate (S205), model years 2014–2021

Mercedes-Benz C-Class Coupé (C205), model years 2015–2023

How is the airbag control unit A2059002512 professionally repaired?

At Airbag24, repairing the A2059002512 control unit follows a standardized process. After removal and shipment, the unit is thoroughly analyzed to confirm the root cause of the fault. Next, crash data are erased, and any defective electronic components on the circuit board are expertly replaced.

The first step involves carefully removing the control unit from the vehicle. Upon receipt at Airbag24, our technicians perform an initial inspection to verify the reported fault, such as the B1BC7-49 code.

The actual repair focuses on eliminating the underlying cause: stored crash data are reset at the chip level, and in cases of internal malfunctions, the responsible components on the circuit board are identified and replaced.

Following restoration, each control unit undergoes a comprehensive functional test to ensure proper operation. You receive 2 years' statutory liability for defects on the completed repair.