Description
Overview
The BSI (Body System Interface) unit BSI04EV K04-00, part number 9664059080 01, removed from a Citro&ebn C4 Picasso, is a central body control module that manages numerous comfort and body functions such as central locking, lighting control, electric windows and communication over the vehicle CAN networks. Manufactured by Johnson Controls, this unit is suitable as a direct-fit replacement for compatible PSA models and is commonly identified by its product number in searches.
Features and Function
This BSI unit coordinates signals between switches, sensors and actuators to control interior and exterior lighting, central locking, electric window operation, alarm and other comfort features. It also acts as a gateway for some vehicle networks, reporting fault codes and status to diagnostic tools. Replacing the BSI typically restores multiple interrelated functions that can fail when the module malfunctions.
Replacement, Coding and Typical Faults
Replacement is straightforward for a trained technician: access the module (usually located behind the dashboard), disconnect the battery, unplug the wiring connectors and fit the replacement unit. After physical installation, most PSA BSI units require coding or immobiliser/key pairing using an official PSA diagnostic tool (for example DiagBox) to ensure full functionality. Common causes of BSI failure include water ingress, corrosion, electrical surges, damaged connectors, degraded solder joints and battery-related issues. Symptoms of a failing BSI include non-functioning central locking, intermittent lights, inoperative windows, warning lights, and communication errors on the dash.
Installation Tips
Before replacing the module, verify fuses and wiring harness integrity. Always disconnect the vehicle battery before removing the BSI and follow anti-static precautions. After installation, perform diagnostic checks and coding where required. If you are a DIYer, consider professional assistance for immobiliser pairing and coding to avoid starter or security issues.
Technical Information
- Manufacturer: Johnson Controls
- Model: Citro&ebn C4 Picasso
- Product Codes: BSI04EV K04-00
- Additional Numbers: 9664059080 01, 657064, 1663370780, BOOT 28120836-4, HARD 28119248-3
This unit has been thoroughly tested and is ready for immediate installation. Always confirm compatibility with your vehicle VIN and consult a diagnostic specialist if coding or immobiliser synchronization is necessary.
