Airbag control unit with part number 6556YV

What is the function of Airbag Control Unit 6556YV?

The airbag control unit with part number 6556YV is the central control module for the Passenger Restraint System (SRS) in the Peugeot 607. It processes signals from acceleration sensors, stores relevant crash data, and, in the event of a serious accident, deploys the airbags and activates seatbelt pretensioners to protect occupants.

As the brain of the Supplemental Restraint System (SRS), this control unit continuously monitors all connected components, including the various airbags, seatbelt pretensioners, and their associated sensors. It constantly analyzes data from the acceleration sensors to detect an impact in real time and activate the necessary restraint systems.

A distinctive feature of these control units is that they automatically deactivate themselves after the safety systems have been triggered—i.e., following a crash. Relevant crash data is permanently stored in the internal memory, preventing reuse without professional repair.

This OEM part number 6556YV is also compatible with identifiers 9640341180, 6545JK, and 9659531880, aiding workshop technicians in correctly identifying the component.

Why does Airbag Control Unit 6556YV fail?

The most common cause of failure for control unit 6556YV is the storage of crash data after an accident, which results in the device being locked by the manufacturer. Additional faults arise from internal electronic malfunctions such as water damage, short circuits, or component failures on the circuit board.

The primary reason for malfunction is the lockout following a crash. The control unit records crash events and locks itself to prevent improper reuse. The airbag warning light illuminates, and the system becomes inoperable. This condition is permanent and can only be resolved through professional repair.

Beyond accidents, electronic defects may also occur. Short circuits, water ingress through body panel leaks, or failure of individual electronic components like capacitors can impair functionality. Such internal issues often lead to error codes like U1XXX or B1XXX that cannot be cleared.

It’s important to note that the control unit isn’t always the root cause of the problem. Faulty cables, loose connectors, defective sensors, or issues with the seat occupancy sensor can produce identical symptoms. Therefore, a thorough vehicle diagnosis is essential before removing the control unit.

How do you recognize a fault in Control Unit 6556YV?

A faulty Airbag Control Unit 6556YV typically manifests as a permanently illuminated or flashing airbag warning light (SRS indicator) on the instrument cluster. Other signs include unerasable error codes or a lack of communication between the control unit and the workshop diagnostic tool.

The clearest indication is the active SRS warning light, signaling a fault in the restraint system and indicating that airbags and seatbelt pretensioners will no longer deploy in the event of a crash. This significantly compromises the safety of vehicle occupants.

Another clear symptom is the absence or disruption of communication with the control unit. When a workshop attempts to read the fault memory using a diagnostic tool, messages such as “No Communication” or “Control Unit Defective” appear. Stored errors cannot be cleared under these conditions.

If the airbags or seatbelt pretensioners have already deployed due to an accident, the control unit should be considered “exhausted” and must be repaired or replaced to restore full functionality of the safety system.

In which vehicles is Control Unit 6556YV installed?

The Airbag Control Unit 6556YV is specifically designed for Peugeot models. It is used in the first-generation Peugeot 607 (production years 2000–2004) as well as in the subsequent facelift model (production years 2004–2010), where it is installed as an original equipment manufacturer (OEM) part.

At Airbag24, we repair the control unit with part number 6556YV and its compatible numbers 9640341180, 6545JK, and 9659531880 for the following models:

Peugeot 607 I (model years 2000–2004)

Peugeot 607 I Facelift (model years 2004–2010)

How does the repair of 6556YV proceed at Airbag24?

At Airbag24, the 6556YV control unit undergoes a professional repair process. Upon receipt, our technicians analyze fault and crash data, rectify defects at the component level, erase crash data, and perform final functional tests to fully restore safety.

After the control unit arrives at our facility, we first read the fault memory to precisely analyze stored DTCs (Diagnostic Trouble Codes) and crash data. This is followed by systematic fault detection on the circuit board using state-of-the-art measurement technology.

Defective electronic components are identified and replaced by qualified technicians. Subsequently, all stored crash data is completely and irreversibly erased from the control unit’s memory. Following repair, each unit undergoes thorough functional testing and calibration to ensure flawless operation.

Repair offers a cost-effective and sustainable alternative to expensive new purchases, as it restores the original part’s full functionality. We provide 2 years' statutory liability for defects on all repairs.