Airbag control unit with part number 9665250280

What is the function of the airbag control unit 9665250280?

The airbag control unit with part number 9665250280 is the central control unit (SRS ECU) for the passive safety system in vehicles such as the Citroën Berlingo II. It processes data from the connected crash sensors to precisely and rapidly deploy airbags and seatbelt pretensioners in the event of a collision.

As the brain of the restraint system, this ECU continuously monitors all safety‑related components, including front and side airbags, seatbelt pretensioners, seatbelt buckle sensors, and acceleration sensors that detect a collision. The device ensures that the system remains operational at all times.

The proper functioning of the control unit is critical for occupant protection. It determines within milliseconds which restraint systems need to be activated. This unit is also known under related variant numbers 608990400 or G3090 and can be found in identical models across the PSA Group.

Why does the control unit 9665250280 fail?

The most common cause of failure for the control unit 9665250280 is the storage of crash data after an accident, which permanently locks the system. Other causes include internal electronic faults due to overvoltage, moisture‑induced contact issues, or the failure of individual components on the circuit board.

Following a collision—even minor ones—the control unit writes so‑called crash data into its internal memory. For safety reasons, this data locks the unit and prevents further use. This lock cannot be removed simply by clearing the fault memory at a workshop; it requires a specialized hardware reset.

Electrical disturbances, such as overvoltage caused by a faulty alternator or jump-starting, can damage sensitive components like capacitors and resistors on the circuit board. Similarly, ingress of moisture can lead to corrosion on contacts and traces, resulting in internal malfunctions.

Mechanical stresses—such as vibrations or improper work inside the vehicle (e.g., beneath the seats or near the center console)—can loosen connectors or cause hairline cracks in the circuit board, disrupting normal operation.

How do you recognize a defect in the 9665250280?

A defect in the control unit 9665250280 primarily manifests as a constantly illuminated airbag warning light (SRS lamp). Often, the unit can no longer be accessed using diagnostic tools, or the specific error code B1111 (control unit defective) is stored in the fault memory.

The most obvious symptom is the persistently lit airbag warning light on the instrument cluster. It does not turn off after starting the engine, indicating a serious, permanent system error that compromises airbag functionality.

Another clear sign is the lack of communication with the control unit. If a workshop attempts to read the fault memory via the OBD2 interface, no connection can be established—the unit fails to respond to diagnostic requests.

In addition to the general error code B1111, more specific internal errors—such as “resistance in the driver/passenger airbag ignition circuit too high,” CAN bus communication failures, or a message indicating insufficient supply voltage—may also point to a defect within the control unit itself.

In which vehicles is the control unit 9665250280 installed?

The airbag control unit with part number 9665250280 is primarily used in PSA Group models from the late 2000s and 2010s, including the Citroën Berlingo II and the mechanically identical Peugeot Partner. At Airbag24, we professionally repair this control unit for the aforementioned models.

At Airbag24, we service part number 9665250280 for the following specific models and series:

Citroën: Berlingo II B9 (model years 2008–2012), Berlingo II 1st facelift (2012–2015), and Berlingo II 2nd facelift (2015–2018).

Peugeot: Partner Tepee, especially in powertrains such as the 1.6 HDi.

How is the control unit 9665250280 professionally repaired?

After being sent to Airbag24, the control unit 9665250280 undergoes a standardized repair process. This begins with an initial inspection, followed by addressing the root cause of the issue—whether it’s clearing crash data or replacing defective components. A final test confirms full functionality.

The process starts with the careful removal of the unit, which in the Citroën Berlingo II is typically located in the center console beneath the handbrake lever. Before removal, the vehicle battery must be disconnected to prevent accidental deployment of airbags.

Upon arrival at Airbag24, the control unit undergoes a thorough analysis. Our technicians identify the exact source of the fault—whether it’s stored crash data, a hardware defect on the circuit board, or a communication error.

The actual repair involves resetting the crash data using specialized equipment and, if necessary, precisely desoldering and replacing defective electronic components such as resistors or capacitors. Finally, the device’s functionality is verified on a test bench to ensure it communicates flawlessly and operates without errors. We provide 2 years' statutory liability for defects on every repair.