Airbag control unit with part number 550897200

What is the function of Airbag Control Unit 550897200?

The airbag control unit with part number 550897200 is the central control module of the passive safety system in models such as the Peugeot Partner I and Citroën Berlingo I. It processes signals from crash sensors to deploy airbags and seatbelt pretensioners in the event of a collision. This unit is often paired with the alternative part number 9638604280.

As an original PSA/Peugeot OEM component, this control unit is responsible for continuously monitoring all relevant data from the restraint system. It analyzes information from acceleration and pressure sensors to assess the severity of an impact. Based on this analysis, it determines which safety systems—such as front or side airbags and seatbelt pretensioners—should be activated and at what intensity.

In addition, the control unit performs continuous self-tests and stores any system faults. These errors are indicated to the driver by the illumination of the airbag warning light on the instrument panel.

Why does Airbag Control Unit 550897200 fail?

The most common cause of failure for control unit 550897200 is the storage of crash data after an accident, even if no airbags were deployed. Other defects arise from internal electronic malfunctions, water damage, damp connectors, or faulty peripherals such as sensors or seat occupancy mats.

After an accident in which seatbelt pretensioners or airbags have been activated, the control unit locks itself internally. So‑called crash data is written into its memory and cannot be erased using standard diagnostic tools. This is a manufacturer‑imposed safety measure that requires replacement or professional repair.

Internal hardware defects are also a frequent cause. These include faulty components on the circuit board, such as capacitors or memory chips. Software errors or malfunctions following improper repair attempts can likewise impair functionality. External factors like moisture ingress lead to corrosion on connectors and the circuit board, causing short circuits and system failures.

How do you recognize a defect in Control Unit 550897200?

A defect in Airbag Control Unit 550897200 primarily manifests as a permanently illuminated or flashing airbag warning light on the dashboard. Another clear indication is when the control unit becomes unreachable via the OBD2 interface, preventing communication with diagnostic equipment.

The most noticeable symptom is the persistently lit airbag warning lamp. It fails to extinguish after starting the vehicle or begins blinking sporadically during driving. This indicates an error stored in the fault memory that compromises system safety.

Another critical sign is loss of communication. The workshop cannot establish a connection with the airbag control unit using diagnostic tools to read or clear fault codes. This often points to a severe internal malfunction.

Even when communication is possible, stored crash data frequently cannot be cleared. The fault memory then displays an internal control unit error or a crash event that cannot be reset. However, it’s important to verify whether the root cause lies in external components, such as broken cables or defective sensors.

In which vehicles is Control Unit 550897200 installed?

As an original PSA/Peugeot part, Airbag Control Unit 550897200 was mainly used in specific model series of the Peugeot Partner I and Citroën Berlingo I. It is not compatible with newer models like the Berlingo B9, which uses different part numbers. At Airbag24, we repair this control unit for the following models:

Peugeot:

- Peugeot Partner I (1996–2002)

- Peugeot Partner I Facelift (2002–2013)

Citroën:

- Citroën Berlingo I (1996–2002)

- Citroën Berlingo I 1st Facelift (2002–2005)

- Citroën Berlingo I 2nd Facelift (2005–2009)

How is Control Unit 550897200 repaired?

After being sent to Airbag24, Control Unit 550897200 undergoes a professional repair process. This begins with a thorough diagnosis to identify the root cause of the fault. Subsequently, stored crash data is cleared, defective electronic components are replaced, and a comprehensive functional test is performed.

The process at Airbag24 follows established procedures. First, the unit undergoes an initial inspection to confirm the reported issue. Central to the repair is addressing the underlying cause—whether it involves professionally resetting crash data or replacing faulty components on the circuit board.

After repair, the control unit is tested on a specialized test bench to ensure the flawless operation of all safety‑critical functions. Only after a successful final test is the device approved for return shipment. We provide 2 years' statutory liability for defects on every repaired unit.