Description
Overview
This used Delphi BSM B2 module is supplied with a guarantee of functionality. The unit may show minor cosmetic damage to a bracket or mounting point, which does not affect electrical performance. It is a practical replacement for PSA vehicles that need a reliable engine-bay control module.
Function And Application
The BSM (Body Systems Module / Boîtier Servitude Moteur) controls fuses, relays and various low-voltage electrical circuits in the engine bay. It coordinates power distribution to lighting, central locking, wipers and other auxiliary systems. A faulty BSM can cause multiple, seemingly unrelated electrical faults, so replacing it often restores several functions at once.
Installation & Compatibility
This module is compatible with Citroën and Peugeot vehicles using PSA part numbers 9644038780 and 6500Y1. Typical replacement steps: disconnect the battery, remove the engine-bay cover or fusebox lid, unplug multi-pin connectors, unbolt the module and fit the replacement unit. After installation, reconnect the battery and clear any diagnostic trouble codes. Because the BSM interfaces with immobiliser and other vehicle systems, installation by a qualified technician is recommended.
Common Failure Modes
- Moisture ingress or corrosion in the engine bay
- Heat-related degradation of electronic components
- Vibration damage to connectors, solder joints or mounting points
- Internal faults due to age, voltage spikes or environmental stress
Technical Information
- Manufacturer: Delphi
- Model: Citroën, Peugeot
- Product Codes: 9644038780, 6500Y1
- Other Numbers: 6500Y1 (alternative code)
Searches for this part are frequently performed by part number, so providing the correct code speeds up compatibility checks. If you need help verifying fitment or guidance during replacement, contact us — we support both professional workshops and experienced DIY mechanics.
