Description
BSM B4 DELPHI for Peugeot and Citroën vehicles. This is a used part with a guarantee of functionality. Some mounting tabs may be damaged — this does not affect functionality.
The BSM B4 (Delphi) is a body control module used on a range of Peugeot and Citroën models to manage multiple vehicle electrical systems. It typically controls lighting circuits, central locking, power windows, wipers, interior lighting and various relays and sensors. Supplied as a used unit in working condition, this part is a direct replacement for vehicles fitted with the referenced OEM codes and is a common spare for workshop repairs or DIY diagnostics.
Fitment And Compatibility
Commonly fitted To: Citroën C8; Peugeot 206; Peugeot 307; Peugeot 807. The unit is referenced on vehicles from Stellantis group using the listed product codes. Buyers often search by part number (see Technical Information below) to confirm fitment.
Technical Information
- Manufacturer: Delphi
- Model: BSM B4
- Product Codes: 9650663980, 6500Y1, 6500Y3
- Additional Numbers: Stellantis/Peugeot/Citroën references related to the above codes
Installation Recommendations
- Disconnect the negative battery terminal and wait a few minutes before starting work to avoid short circuits.
- Locate the BSM unit (commonly mounted behind the glovebox or under the dashboard depending on model) and remove any trim panels to gain access.
- Carefully release connector locking tabs and unplug the wiring harness. Inspect connectors for corrosion or bent pins before fitting the replacement.
- Remove retaining bolts, fit the replacement unit and secure all fasteners. Reconnect harnesses and refit trim.
- After installation, restore battery connection and verify all controlled functions (lights, locks, windows, wipers, etc.). Some vehicles may require module programming/coding or key synchronization with dealer-level or aftermarket diagnostic tools — professional programming equipment is recommended if the vehicle shows immobilizer or communication faults after replacement.
Most Common Failure Reasons
- Moisture Ingress And Corrosion: Water or condensation can corrode pins and printed circuit traces, causing intermittent faults.
- Electrical Surges Or Short Circuits: Faulty components elsewhere (shorted lamps, bad actuators) can create voltage spikes that damage electronic modules.
- Ageing And Thermal Stress: Repeated heating and cooling cycles can cause solder joint cracks, failing relays or degraded components.
- Connector Wear Or Mechanical Damage: Repeated disconnections, poor contact or physical impact can lead to communication or power failures.
What To Check Before Replacement
- Inspect Related Fuses And Relays For Visible Damage Or Blown Elements.
- Check Battery Condition And Charging System To Rule Out Voltage Irregularities.
- Examine Wiring Harness And Connectors For Corrosion, Water Traces Or Pin Damage.
- Confirm Symptoms Across Multiple Functions (If Only One Circuit Is Affected, Replace Or Test The Specific Fuse/Relay First).
This used BSM unit offers a cost-effective way to restore multiple electrical functions on compatible Peugeot and Citroën models. Include the part numbers 9650663980, 6500Y1 or 6500Y3 in your search to improve the chance of finding the correct replacement for your vehicle.
