Function

The BSM B2 by Delphi is the engine compartment fuse and relay box responsible for power distribution and circuit protection for numerous engine-related systems. It contains fuses, relays and associated electronics that supply power to ignition circuits, cooling fans, fuel system auxiliaries, lighting and other engine bay consumers. Correct operation of the BSM ensures stable power delivery and protection against short circuits and overloads.

Fitment

Designed for Stellantis Group vehicles including Citroën and Peugeot models. Common applications include Citroën Xsara Picasso and Peugeot 206 and 307. The unit is often searched for under part numbers 9650664180 and 6500Y1.

Replacement Procedure

Before starting any work, always disconnect the negative battery terminal and follow the vehicle manufacturer’s safety procedures. Typical replacement steps:

• Locate the BSM in the engine bay (usually protected by a plastic cover near the battery or inner wing).
• Remove the protective cover and any obstructing components to gain access.
• Carefully unplug all electrical connectors, noting or photographing their positions to ensure correct reassembly.
• Remove mounting fasteners and extract the BSM. Take care with plastic clips which may be brittle.
• Install the replacement unit, secure all fasteners, reconnect connectors and replace covers.
• Reconnect the battery and verify the operation of affected systems (lights, starter, fans, etc.).

Why The Part Fails Most Often

Common causes of BSM failure include water ingress and corrosion in connectors, thermal cycling and age-related deterioration of electronic components, electrical overloads or short circuits, and mechanical damage to plastic housings or mounting clips due to vibration. As noted, broken or damaged mounting clips are frequently observed on used units but typically do not affect electrical functionality.

Technical Information

• Manufacturer: Delphi
• Model: BSM B2
• Product Codes: 9650664180, 6500Y1
• Additional Numbers: 6500 Y1

Installation Recommendations

• Always disconnect the battery before removal or installation.
• Inspect all connector pins and wiring for corrosion or damage and clean or repair as needed.
• Replace any broken mounting brackets or clips to ensure the unit is properly secured and protected from vibration.
• Use dielectric-safe contact cleaner on electrical connectors and apply contact protection if appropriate.
• After installation, perform a full electrical check of systems powered by the BSM and clear any logged fault codes if necessary.
• If unsure about disassembly/reassembly or diagnostics, seek professional service with the proper tools and diagnostic equipment.

Product Overview

High-quality BSM B2 Delphi control unit suitable for many Citroën and Peugeot vehicles equipped with Delphi BSM modules. This used unit is supplied with a functionality guarantee and is intended for professional garages and experienced DIY mechanics who service vehicle electrical and control systems. Commonly referenced by product codes such as 9650664180 and 6500Y1, this module replaces faulty body/control units that cause electrical malfunctions, central locking issues, or irregular behaviour of vehicle electronics.

Key Functions

• Manages multiple vehicle electrical subsystems depending on vehicle configuration (lighting, central locking, interior electronics, signals).
• Interacts with engine and comfort systems via vehicle CAN networks where applicable.
• Provides input/output switching, diagnostics interface and protection against electrical faults within its scope of control.

Installation Notes

Replacement should be performed by a trained technician or a competent DIYer familiar with vehicle electronics. Typical replacement steps:

• Disconnect the negative terminal of the battery and wait several minutes to ensure system discharge.
• Locate the BSM unit (position varies by model: often behind glovebox, under dashboard or in the engine bay mounting points).
• Carefully release connectors and locking tabs; note connector orientations and harness routing.
• Remove mounting screws or clips, swap the unit and reattach connectors ensuring firm engagement and correct pin alignment.
• Reconnect battery and run basic checks: power-up, fault-code scan and verify controlled functions.

Technical Information

• Manufacturer: Delphi
• Model: BSM B2
• Product Codes: 9650664180, 6500Y1
• Additional Numbers: 6500.Y1., 6500Y1, 9650664180

Recommendation For Mounting

Always follow the vehicle manufacturer’s procedures when removing and fitting control units. Use correct torque for fasteners and secure all wiring harnesses to avoid chafing. After installation, perform a full systems check and clear any historical fault codes. If the vehicle requires adaptation or coding of the unit, use appropriate diagnostic equipment.

Why This Part Fails Most Often

Typical causes of BSM failure include moisture ingress and corrosion at connectors, damage from impact or improper handling, and electrical stress from voltage spikes or poor battery connections. Mechanical damage to mounting brackets is common on used units but usually does not affect the unit’s electronic functionality. Aging components and intermittent connector contact may also produce sporadic faults.

More About Reliability And Use

This used unit is offered with a guarantee of functionality. For workshops and experienced DIY mechanics it provides a cost-effective alternative to a new unit when the original module shows faults. Verify connector compatibility and product codes before installation. After fitting, perform diagnostic verification to ensure all controlled systems respond correctly.