OEM Siemens airbag control unit (SRS ECU) designed for early Peugeot 307 models. This unit is a direct replacement option for garages and experienced DIY mechanics who search by part number 9645840780, 5WK42908 or reference codes 6545HE / 6545HF. A reliable SRS control module restores proper airbag and seatbelt pretensioner monitoring, clears persistent fault codes when correctly installed, and helps ensure safety systems operate as intended after repair.

Technical Information

• Manufacturer: Siemens
• Model: Peugeot 307 (up to 2004)
• Product Codes: 9645840780, 5WK42908
• Additional Numbers: 6545HE, 6545HF, NFP

Compatibility

Fits Peugeot 307 (first generation) vehicles produced up to 2004. Intended as a replacement SRS module for original equipment configurations that use the listed product codes. Always confirm the part numbers printed on the existing unit before ordering to ensure direct fit.

Function

The airbag control unit (SRS ECU) continuously monitors crash sensors, seatbelt pretensioners and airbag circuits. In the event of a collision the unit evaluates sensor signals and triggers deployment of airbags and pretensioners when required. The module also stores fault codes and crash event data, and communicates with other vehicle systems to illuminate the airbag warning lamp if a fault is detected.

Replacement Procedure

High-level replacement steps for experienced technicians: disconnect the negative battery terminal and wait at least 10 minutes to allow residual charge to dissipate; remove trim panels to access the SRS unit (commonly located under the center console or behind the dashboard); unplug connectors and remove the retaining fasteners; fit the replacement unit, reconnect connectors and reassemble trim. After installation, perform a full diagnostic check and clear any stored fault codes with a suitable PSA diagnostic tool. Verify that the airbag warning lamp extinguishes and that no new faults are present.

Installation Recommendations

Always follow manufacturer safety procedures. Disconnect the battery before work and avoid shorting SRS connectors. Handle the unit carefully and do not strike or expose it to strong static. Ensure connector pins and sockets are clean and free of corrosion. Use a professional-level diagnostic tool capable of reading and clearing SRS faults and performing system self-tests. If crash data is present, replace components according to safety regulations and local law.

Most Common Failure Reasons

The SRS control unit rarely fails from normal wear. Typical causes of malfunction include prior crash events that damage internal circuitry, water ingress or corrosion affecting connectors, physical damage during prior repairs, and electrical surges or wiring faults. Persistent airbag warning lamp, stored SRS fault codes or communication errors often indicate a defective module or related sensor/wiring issue that requires targeted diagnosis.

Who Should Install

Recommended for professional technicians or experienced DIYers familiar with SRS systems and equipped with appropriate diagnostic tools. Due to safety-critical functions, correct diagnosis, installation and post-replacement verification are essential.

Replacing the airbag unit is a straightforward process that typically involves disconnecting the battery, removing the airbag cover, and carefully detaching the old unit from its connectors before installing the new one. It’s recommended that this replacement is carried out by qualified personnel to ensure safety and compliance with vehicle regulations.

Technical Information

• Manufacturer: Siemens
• Model: Peugeot 307
• Product Codes: 9652712180
• Additional Numbers: 6545HE, 6545HF

Understanding the functionality of the airbag unit is crucial, as it is responsible for deploying the airbags in the event of a collision, thereby providing essential protection for the driver and passengers. Regular diagnostics can help identify any potential issues with the airbag system before they escalate, ensuring continued safety on the road.