Airbag control unit with part number 6545HE

What is the function of the airbag control unit 6545HE?

The airbag control unit with part number 6545HE is the central control module for the occupant restraint system (SRS) in certain Peugeot 307 SW I models. It processes signals from crash sensors to precisely and promptly deploy airbags and seatbelt pretensioners in the event of a collision.

As a safety-critical component, this unit continuously monitors all connected components of the restraint system, including front and side airbags, seatbelt pretensioners, and acceleration sensors that detect a collision. Based on this data, the control unit determines within milliseconds which safety devices need to be activated.

At the same time, the module stores all system-relevant faults and events—such as deployed seatbelt pretensioners or post-crash data—which are essential for vehicle diagnostics and repair.

Why does the airbag control unit 6545HE fail?

The most common causes of failure for the 6545HE control unit include stored crash data after an accident that locks the device, as well as internal hardware defects. These include damaged electronic components such as voltage regulators, short circuits on the circuit board, or corrosion caused by water ingress.

A major reason for repair requests is the storage of crash data. After a collision where seatbelt pretensioners or airbags have been deployed, the control unit locks itself internally, rendering it unable to perform its functions—even if there are no visible damages left on the vehicle. Clearing this data is essential for reactivating the system.

Electronic defects on the circuit board are also widespread. Faulty SMD components, defective voltage regulators, capacitors, or MOSFETs can lead to total failure or malfunctions. Short circuits or damaged traces—often due to aging or external factors—can likewise impair functionality.

External influences such as water damage represent another frequent source of failure. Penetrating moisture causes corrosion at connector pins and on the circuit board itself, resulting in unreliable connections and short circuits. Less commonly, voltage fluctuations—for example, from a faulty jump-start involving reverse polarity—can cause irreparable damage to the internal circuitry.

How do you recognize a defect in the 6545HE control unit?

A defective 6545HE airbag control unit primarily manifests as a permanently illuminated or flashing airbag warning light on the instrument cluster. Often, communication between a diagnostic tool and the control unit breaks down entirely, making it impossible to read fault codes.

The clearest symptom is the active airbag warning light (SRS light), which indicates a fault in the restraint system and fails to extinguish after starting the vehicle. This suggests that the airbags may not deploy in the event of a crash.

Another clear sign is complete loss of communication: when a workshop attempts to read the fault memory, the diagnostic tool receives no response from the airbag control unit. This points to a severe internal hardware failure or a disruption in power supply.

In some cases, fault codes can still be retrieved, directly indicating an internal defect in the control unit. Such DTCs (Diagnostic Trouble Codes) signal that the module has detected a self-diagnostic error and needs replacement or repair.

In which vehicles is the 6545HE control unit installed?

The airbag control unit with part number 6545HE is specifically used in Peugeot vehicles. It is intended for various variants of the first-generation Peugeot 307 SW, including the facelift model.

At Airbag24, we repair the 6545HE control unit for the following models:

Peugeot 307 SW I (model years 2001–2005)

Peugeot 307 SW I Facelift (model years 2005–2009)

How does the repair of the 6545HE proceed at Airbag24?

The repair process for the 6545HE at Airbag24 includes a detailed initial diagnosis, electronic restoration of defective components, and deletion of stored crash data. Following successful repair and testing, the control unit is prepared for reinstallation, backed by 2 years' statutory liability for defects.

First, the control unit is removed from the vehicle and shipped to us. For precise diagnostics, it’s helpful to provide the vehicle identification number (VIN) and any previously read fault codes.

Upon receipt at Airbag24, a comprehensive analysis begins, starting with a visual inspection of the circuit board and connectors for corrosion or mechanical damage. Subsequently, efforts are made to retrieve stored fault codes and crash data to determine the exact nature of the issue.

The actual electronic repair focuses on eliminating the identified cause. Defective components such as voltage regulators, capacitors, or other SMD parts are replaced professionally. Where technically feasible and legally compliant, stored crash data is reset to restore the control unit’s functionality.

The repaired unit comes back with all vehicle data and is ready for immediate use after reinstallation — coding or programming is not necessary. Finally, the repaired unit is tested and prepared for return shipment. We provide 2 years' statutory liability for defects on every repair.