Description
BSI Unit Siemens for Peugeot 406 Vehicles.
Product Overview
This BSI D9 Siemens unit is a comfort/body control module originally fitted to Peugeot 406 models. Supplied with product codes often referenced in parts searches (9640091280, S108551300 H, 658026), the module manages multiple vehicle comfort and safety functions. Ideal for mechanics and DIY enthusiasts who search by part number, this BSI unit is a direct-swap electrical module that restores or replaces faulty body control functions when correctly matched and configured.
What The BSI Does
The Body Systems Interface (BSI) is the central comfort and gateway module that coordinates functions such as interior and exterior lighting, central locking, electric windows, wipers, alarm/immobilizer interface, courtesy lights and certain instrument cluster signals. It routes inputs from switches and sensors to the appropriate actuators and communicates with other control units on the vehicle network.
Typical Fault Symptoms
- Intermittent or non-functional central locking and remote functions
- Malfunctioning interior/exterior lights or automatic lighting circuits
- Electric windows or wipers operating erratically or not at all
- Instrument cluster warnings, immobilizer-related starting issues or no crank
- Random electrical anomalies and fuse-blowing events
Technical Information
- Manufacturer: Siemens
- Model: Peugeot 406
- Product Codes: 9640091280, S108551300 H, 658026
- Additional Numbers: Stellantis Citroen Peugeot (as referenced on part markings)
Installation Recommendations
Always disconnect the vehicle battery before starting removal or installation to avoid short circuits and potential damage to the unit. The BSI is typically located behind the dashboard or in the passenger footwell area, often mounted near the fusebox. Remove surrounding trim panels and the glovebox if necessary to access mounting screws and connectors. Carefully unplug multi-pin connectors using appropriate release tools, avoiding forced pulls on wiring harnesses.
When installing the replacement unit, ensure all connector pins and seals are clean and undamaged, refit the unit securely, and reconnect the battery only after reassembly. If the unit has been cloned or virginized, follow the coding steps below before returning the vehicle to service.
Installation And Coding – Important
- The unit is used and is “paired” with the original vehicle (VIN/PIN/keys).
- Options to put the unit into operation:
- Cloning data from the old unit (EEPROM/Flash) – after cloning the unit is plug and play.
- Virginization and subsequent initialization/telecoding via DiagBox (or online) + key adaptation.
- Recommended to be performed by a professional with PSA service equipment (DiagBox/Lexia/PP2000).
- Always disconnect the battery before removal/installation and follow the manufacturer procedure to avoid damaging the unit.
Why This Part Fails
BSI units commonly fail due to moisture ingress and corrosion, electrical surges or short circuits, degraded solder joints from thermal cycling, or connector corrosion. Age-related wear and exposure to contaminants (water, salt) accelerate failure. Faults are more frequent on high-mileage vehicles or cars that have experienced water leaks or electrical faults.
Practical Tips For Mechanics
- When possible, compare the product codes on the replacement unit to the faulty unit to ensure exact match.
- If cloning is chosen, extract EEPROM/Flash data from the original unit before removal so vehicle immobilizer and key data are preserved.
- After installation, perform a full systems scan and test all comfort functions to confirm proper operation and to detect any remaining wiring faults.
Compatibility Note
This listing references Peugeot 406 and the product codes above. Search by the part numbers (9640091280, S108551300 H, 658026) to confirm fitment with your specific vehicle and equipment level.
