Airbag control unit with part number 9857895980

What is the function of the airbag control unit 9857895980?

The airbag control unit with part number 9857895980 is the central control module for the occupant safety system (SRS) in vehicles such as the Peugeot 308 III and Opel Astra L. It analyzes data from crash sensors and, in the event of an accident, deploys the airbags and activates the seatbelt pretensioners. An identical variant is known under OE number 624926000.

The control unit continuously monitors all safety‑related components of the airbag system, including the various crash sensors installed at strategic points throughout the vehicle, as well as the individual airbag modules and seatbelt pretensioners.

Its primary task is to evaluate acceleration and deceleration values provided by the sensors in real time. Based on this data, the electronics determines within milliseconds whether a collision has occurred and which restraint systems need to be activated.

Why does the airbag control unit 9857895980 fail?

A failure of control unit 9857895980 is most commonly caused by stored crash data following an accident, which the unit locks out for safety reasons. Another cause is internal hardware defects on the circuit board, such as faulty SMD components, cold solder joints, or damaged traces.

After an accident in which the airbags have deployed, the control unit stores so‑called crash data. This data locks the module and prevents reuse without professional repair, serving as a deliberate safety feature.

Even without an accident, purely electronic faults can occur, including defective integrated circuits (ICs), capacitors, or resistors on the board.

Physical factors like moisture can also lead to corrosion and breakage of traces or cold solder joints, impairing functionality. Therefore, a thorough diagnosis while the unit is removed is essential to identify the exact cause of the fault.

How do you recognize a defect in control unit 9857895980?

The clearest symptom of a defect in control unit 9857895980 is the permanently illuminated airbag warning light on the dashboard. Additionally, the unit may no longer respond to a diagnostic tool, or specific internal error codes may be stored in the fault memory.

If the SRS warning light remains on after starting the engine, it indicates a fault. This is the primary and most important alert to the driver that the occupant safety system is either non‑functional or only partially operational.

In the workshop, the defect may manifest as an inability to establish communication with the airbag control unit. The diagnostic tool receives no response, pointing to a serious internal issue.

Alternatively, the diagnostics may output error codes such as B1000 or similar, directly indicating a fault within the control unit itself. However, it is crucial first to rule out external sources of failure, such as defective sensors or broken cables.

In which vehicles is control unit 9857895980 installed?

The airbag control unit with part number 9857895980 is used in modern vehicles from the PSA Group. It is primarily found in the third‑generation Peugeot 308 model line and in the Opel Astra L, which is based on the same technical platform.

At Airbag24, we repair part number 9857895980 as well as the comparable OE number 624926000 for a range of specific vehicle models.

Compatibility extends to the following vehicles:

Peugeot 308 III (2021–2025)

Peugeot 308 III Facelift (2025–present)

Opel Astra L (2022–present)

How is control unit 9857895980 professionally repaired?

Professional repair at Airbag24 begins with a detailed diagnosis of the fault memory. Stored crash data is then cleared, and defective electronic components on the circuit board are replaced through micro‑soldering. A final functional test ensures quality, covered by 2 years’ statutory liability for defects.

Upon receipt of the control unit at Airbag24, a comprehensive incoming inspection is performed. Technicians read the internal fault memory to pinpoint the exact cause—whether it’s stored crash data or an electronic defect.

The actual restoration takes place at the component level. Defective SMD components are precisely replaced using hot‑air and rework stations, and solder joints are renewed. If necessary, damaged traces are also expertly repaired.

Once the repair is complete, each control unit undergoes an extensive functional test on a test bench. This ensures that all functions have been restored and that the device can communicate flawlessly with the vehicle.