Description
Product Overview
This BSI (Body System Interface) module BSI04EV K04-00 originating from a Citroën C4 Picasso is a critical central control unit for comfort and body systems. Supplied as a used automotive electronic part, it is aimed at professional mechanics and competent DIY enthusiasts who prefer an efficient, cost-effective replacement by part number.
Function And Benefits
The BSI controls and coordinates multiple comfort and body electronics including central locking, interior and exterior lighting logic, power windows, alarm/immobiliser interfaces and various switch inputs. Replacing a faulty BSI can immediately restore erratic or lost functionality of these systems and avoid more invasive repairs.
Compatibility And Fitment
Primary fitment: Citroën C4 Picasso. The module is commonly referenced by the part numbers printed below; compatibility should always be confirmed against the vehicle VIN and the exact part number (9664059080 01). Some PSA Citroën & Peugeot models sharing the same BSI family may accept this unit—verify cross-references before installation.
Replacement And Installation Notes
Typical replacement steps (general guidance):
- Disconnect the vehicle battery before starting to avoid short circuits.
- Remove necessary trim panels in the dash or glovebox area to access the BSI housing.
- Unplug all connectors carefully, noting their positions; remove mounting fasteners and extract the old unit.
- Install the replacement BSI, reconnect connectors and reassemble trims.
- Re-connect the battery. In many vehicles, the replacement module will require diagnostic confirmation, coding or immobiliser synchronization using a PSA-compatible diagnostic tool to restore full functionality.
Estimated labour time: typically 0.5–1 hour depending on access and whether coding is required.
Common Failure Causes And Service Life
BSI failures are most often caused by moisture ingress, corrosion on connector pins, voltage spikes, thermal stress or aging electronic components. Symptoms include intermittent or permanent loss of central locking, inconsistent lighting behavior, or failure of powered windows. Regular inspection of connectors and protection against water exposure can prolong service life.
Technical Information
Manufacturer: Johnson Controls
Model: Citroën C4 Picasso
Product Codes: BSI04EV K04-00
Other Numbers: 9664059080 01, 657064, 1663370780, BOOT 28120836-4, HARD 28119248-3
This unit has been made available for immediate installation. Always confirm compatibility by part number and, where required, plan for diagnostic coding or synchronization to the vehicle after fitting.
