Description
BSC B04-00 Siemens VDO Continental for trailer connection for Citroën and Peugeot vehicles.
Used trailer control unit BSC B04-00 engineered to restore trailer connection functions on compatible Citroën and Peugeot models. Suitable for professional workshops and experienced DIY mechanics, this unit manages trailer detection, lighting outputs and CAN-bus communication with the vehicle body systems to ensure safe towing and correct signalling. Commonly searched by product codes such as 9678751080, S180085005A and 9688EL.
Technical Information
- Manufacturer: Siemens VDO / Continental
- Model: BSC B04-00
- Product Codes: 9678751080; S180085005A; 9688EL
- Other Numbers: B03-00; B04-00
- Compatible Models: Citroën Berlingo III; Citroën C4 Picasso; Peugeot 3008 I; Peugeot 5008 I; Peugeot Partner III
Installation And Coding – Important
- The unit is used and is “paired” with the original vehicle (VIN/PIN/keys).
- Options for commissioning:
- Cloning data from the old unit (EEPROM/Flash) – after cloning the unit is plug and play.
- Virginization and subsequent initialization/telecoding via DiagBox (or online) + key adaptation.
- Recommended to be performed by a specialist with PSA service equipment (DiagBox/Lexia/PP2000).
- Before removal/installation always disconnect the battery and follow the manufacturer’s procedure to avoid damaging the unit.
Installation Recommendations
Access to the BSC unit typically requires removal of interior trim or protective covers. General safe replacement steps:
- Disconnect the negative battery terminal before any work to prevent short circuits and unit damage.
- Locate and remove the covering panels to access the unit (refer to the vehicle repair manual for exact location and removal sequence).
- Label and carefully unplug connectors. Inspect pins and connectors for corrosion or bending.
- Remove fasteners, extract the old unit and fit the replacement in the original orientation. Reconnect connectors securely and reinstall fasteners.
- Complete commissioning by cloning or telecoding as required (see Installation And Coding – Important).
Why The Part Most Commonly Fails
- Water ingress and corrosion from damaged seals or exposed wiring, especially on vehicles used for towing in wet conditions.
- Electrical faults caused by short circuits or incorrect trailer wiring (overloads can damage outputs).
- Connector damage and pin corrosion from vibration or improper mating during trailer connection.
- Software or configuration faults after battery replacement or module replacement that require cloning or reinitialization.
Fitment And Practical Notes
When searching for the correct unit, use the product codes listed above. The unit is intended for the listed Citroën and Peugeot models but compatibility depends on the vehicle’s original configuration and the installed body electronics options. Installation and coding steps are critical to restore full functionality of trailer detection and lighting. For reliable results, cloning or proper telecoding with PSA diagnostic tools is recommended.
Keywords
BSC B04-00, Trailer Control Unit, Citroën Trailer Module, Peugeot Trailer Module, 9678751080, S180085005A, 9688EL, Siemens VDO, Continental.
