Description
Autoliv Airbag Control Unit for Citroën Xsara Picasso
High-quality airbag control unit (SRS ECU) compatible with Citroën Xsara Picasso, commonly referenced under product codes 602327400, 9659111980 and 6556RA. Designed for professional workshops and experienced DIY enthusiasts who maintain or repair Stellantis vehicles, this unit replaces a failed SRS controller to restore airbag and seatbelt pretensioner functionality and clear related fault codes when properly installed and coded.
Technical Information
- Manufacturer: Autoliv
- Model: Citroën Xsara Picasso
- Product Codes: 602327400, 9659111980, 6556RA
- Additional Numbers: Stellantis / Citroën / Peugeot references
Function and Application
The airbag control unit (SRS ECU) continuously monitors crash sensors, seatbelt pretensioners and related inputs. In the event of a collision it evaluates sensor data and commands deployment of airbags and pretensioners. It also stores crash-event data and fault codes and communicates with vehicle networks (CAN). As a safety-critical module, correct installation and post-fit diagnostics are essential.
Compatibility And Fitment
Intended for Citroën Xsara Picasso applications. This unit is often searched by the listed OEM/product codes, so entering the reference numbers in vehicle parts searches improves findability. Always confirm physical connector and mounting compatibility before installation.
Replacement Procedure
- Safety First: Disconnect the battery negative terminal and wait the recommended time (typically 10–15 minutes or follow manufacturer guidance) to allow SRS capacitors to discharge.
- Access: Remove the necessary interior trim panels or seats to reach the control unit. (Location may vary by model and trim.)
- Removal: Unbolt the unit, carefully unplug electrical connectors and remove any securing brackets. Mark connectors if needed to ensure correct reconnection.
- Installation: Fit the replacement unit, secure bolts to manufacturer torque values and reconnect all connectors.
- Post-Fit Diagnostics: Use an appropriate diagnostic tool to clear SRS fault codes, verify communication with the module and confirm the SRS warning lamp extinguishes. If required, perform any initialization procedures specified by the manufacturer.
Installation Recommendations
- Always disconnect the battery before starting and follow vehicle manufacturer procedures to avoid accidental airbag deployment or module damage.
- Use a professional diagnostic tool to clear fault codes and run system checks after installation.
- Avoid pulling on wiring harnesses; inspect connectors for corrosion or bent pins and replace damaged hardware.
- When in doubt, have a trained technician perform the replacement—SRS systems are safety critical.
Common Failure Causes
- Crash Deployment: Units that have recorded a deployment event commonly need replacement or special handling after a collision.
- Water Ingress And Corrosion: Moisture or fluid leaks can corrode connectors and internal electronics, causing intermittent faults or failure.
- Electrical Damage: Short circuits, power surges or improper battery handling (jump-starting/wrong polarity) can damage the ECU.
- Connector/Wiring Faults: Broken wires, poor grounding or damaged pins lead to communication errors and warning lights.
- Aging Components: Over many years, internal components can degrade and cause sporadic or permanent faults.
Why This Unit
This Autoliv airbag control unit carries the known OEM references and is suitable for workshops and experienced independent mechanics searching by part number. Replacing a faulty SRS ECU with the correct referenced unit restores proper system operation and passenger safety when installed and diagnosed correctly.
