Airbag control unit with part number A1679008701

What is the function of the airbag control unit A1679008701?

The airbag control unit A1679008701 is the central control module for the passive safety system in the Mercedes-Benz GLS-Class X167. It continuously monitors all sensors, processes crash data in an emergency, and controls the deployment of airbags, seatbelt pretensioners, as well as safety‑related components such as the fuel shut-off valve.

As an original part from Mercedes-Benz, often developed in collaboration with specialists like Autoliv or Siemens, this control unit is precisely tailored to the vehicle architecture of the GLS X167 (from model year 2019 onward). It is listed in official parts catalogs such as TecDoc and serves as the brain of the entire occupant protection system.

In the event of a collision, the module analyzes data from acceleration and pressure sensors within milliseconds. Based on the severity and type of impact, it determines which restraint systems must be activated to provide optimal protection for occupants.

In addition to airbags and seatbelt pretensioners, the control unit also activates secondary safety measures, including actuating the fuel shut-off valve to interrupt fuel supply and thereby minimize the risk of fire after a crash.

Why does the control unit A1679008701 fail?

The most common cause of failure for the control unit A1679008701 is internal hardware defects in electronic components. Another frequent issue is the storage of crash data after an accident, which causes the unit to lock down for safety reasons, preventing it from functioning again. Moisture damage can also lead to malfunctions.

Internal hardware failures are the primary source of problems. These may affect components on the circuit board that fail without any external influence, disrupting the proper operation of the control unit. Such faults are typical in complex electronic control modules.

After a crash, the unit permanently stores the crash data. This lockout is a safety precaution ensuring that the vehicle undergoes professional inspection following a severe impact. The control unit then becomes blocked and requires professional reset.

Other potential causes include moisture damage due to leaks in the vehicle or improper repair attempts in the past, which can result in secondary damage to sensitive electronics.

Although related part numbers such as A1679000009 or A1679008309 exist for the GLS X167, repairing the originally installed unit A1679008701 is often the safest solution to ensure full compatibility.

How do you recognize a fault in the A1679008701?

A defect in the control unit A1679008701 typically manifests as a permanently illuminated airbag warning light on the dashboard. Additionally, communication with a diagnostic tool may become impossible, often displaying error codes such as B00A002 or “internal error.” Messages like “airbags defective” are also common.

The clearest indication is the airbag warning light, which fails to turn off after starting the engine or flashes sporadically during driving. This signals a critical fault in the safety system that requires immediate attention.

Another clear symptom occurs when a workshop cannot establish communication between the diagnostic tool and the airbag control unit. In such cases, the fault memory cannot be read or cleared, indicating a complete loss of communication.

Following a crash, specific messages may appear on the display, such as “airbags defective” or an alert regarding the “fuel shut-off valve.” These indicate that stored crash data has locked the system.

In rarer instances, accompanying symptoms like a faint glow from the warning light or malfunctioning instrument panel illumination may also point to a control unit defect.

In which vehicles is the A1679008701 installed?

The airbag control unit with part number A1679008701 is a specific original component exclusively fitted in the Mercedes-Benz GLS class SUV of the X167 series from model year 2019 onward. At Airbag24, we offer expert repairs tailored specifically to this model.

At Airbag24, we repair part number A1679008701 for the following vehicle model:

Mercedes-Benz: GLS X167 SUV (2019–present)

While repair procedures for control units in other Mercedes models, such as the predecessor GLS X166, may be similar, the hardware and software of part number A1679008701 are specially designed to match the electronic architecture of the X167. Therefore, repairing the original part is often preferable to replacing it with a used one.

How is the A1679008701 professionally repaired?

Professional repair offers a proven, cost-effective alternative to expensive new parts. After sending the unit to Airbag24, it undergoes precise diagnostics, component-level repair, and a reset of the crash data. The entire process is backed by 2 years' statutory liability for defects.

Before removal, a diagnostic check should be performed on the vehicle to confirm that the fault lies definitively with the control unit. The unit is then removed by a qualified workshop and shipped to us in secure packaging.

At Airbag24, our technicians conduct an incoming inspection to pinpoint the exact defect. Repairs are carried out at the component level, replacing faulty parts on the circuit board. For units with stored crash data, a full factory‑reset is performed.

Following successful repair, the control unit undergoes a final test to ensure proper functionality and communication. This guarantees that the module will operate fully as intended after installation. We provide 2 years' statutory liability for defects on every repair.