Airbag control unit with part number 626181500

What is the function of Airbag Control Unit 626181500?

The part number 626181500 refers to an airbag control unit for the Citroën DS3 I and its facelift model. It serves as the central control unit of the Supplemental Restraint System (SRS) and is responsible for processing sensor data and promptly activating airbags and seatbelt pretensioners in the event of a crash.

As a core component of the passive safety system, this module continuously monitors all connected sensors, such as acceleration and seat‑occupancy sensors. The electronics analyze incoming signals in real time to reliably detect an impending collision.

When a critical signal indicating a crash is received, the control unit deploys the appropriate restraint systems—front and side airbags, as well as seatbelt pretensioners—to provide optimal protection for occupants. Following deployment, it also stores crash data, which the system then locks out for reuse.

Why does Control Unit 626181500 fail? Common defects.

The most frequent causes of failure for Control Unit 626181500 are internal electronic damage due to voltage spikes or mechanical impact, contact issues caused by corroded connectors, and the storage of crash data after an airbag deployment, which permanently locks the module.

A primary reason for repair is electronic faults on the circuit board. Short circuits, voltage surges in the vehicle’s electrical system, or mechanical damage—such as that sustained in a crash—can destroy components like SMD resistors, MOSFETs, or capacitors.

Also critical are damaged or corroded connectors and associated wiring, particularly those leading to the seatbelt pretensioners. Loose connections result in communication errors and are logged as faults in the error memory, triggering the SRS warning light.

After a collision with airbag deployment, so‑called crash data is irrevocably stored in the control unit. For safety reasons, this data locks the module and prevents further use. The control unit then reports an internal, non‑erasable fault.

How do you recognize a defect in the Airbag Control Unit?

A defect in Control Unit 626181500 primarily manifests as the SRS airbag warning light remaining constantly illuminated on the instrument panel. Additionally, communication with the module via a diagnostic tool may be disrupted or impossible, and specific error codes indicating an internal device fault are recorded.

The clearest sign is the active airbag warning light, which fails to extinguish after the engine starts. This indicates a serious fault in the restraint system that must be inspected immediately at a specialized workshop.

In the workshop, the defect often becomes apparent when the control unit no longer responds to diagnostic requests through the OBD interface. Access to the error memory or live data is then unavailable.

If error codes can be successfully read, specific entries such as B1111 or references to an internal fault point to a defect within the control unit itself. Such errors cannot be resolved simply by clearing the memory.

In which vehicles is Control Unit 626181500 installed?

The airbag control unit with part number 626181500 is specifically used in models from the Citroën brand. At Airbag24, we professionally repair this module for the first-generation Citroën DS3 as well as its revised facelift version.

Repair services for this control unit are available for the following models:

Citroën: DS3 I (model years 2010–2016)

Citroën: DS3 I Facelift (model years 2016–2019)

How is Control Unit 626181500 professionally repaired?

At Airbag24, repairing Control Unit 626181500 follows a rigorous process: After an initial inspection, defective components on the circuit board—such as SMD parts—are replaced, cold solder joints are reworked, and stored crash data is securely erased. A final functional test ensures quality.

Upon submission to Airbag24, the control unit undergoes a detailed diagnosis. First, the circuit board is visually inspected for obvious damage, including burnt components, cracks in traces, or corroded contacts.

Subsequently, specialized measuring devices are used to perform targeted tests on critical circuits. Defective electronic components—such as resistors, MOSFETs, capacitors, or fuses—are identified and replaced with new, high‑quality equivalents at the chip level. Damaged connector pins or traces are also expertly repaired.

If crash data has been stored, it is deleted using specialized procedures, restoring the module to factory settings. This crucial step ensures full functionality and helps avoid costly replacement purchases.

Upon completion of the repair, a comprehensive functional and communication test is performed on a test bench. Only after the control unit passes all tests is it approved for return shipment. We provide 2 years' statutory liability for defects on every repair.