Product Overview

This used Airbag Control Unit (Airbag ECU) manufactured by Autoliv is intended for Citroën Xsara Picasso vehicles. The unit monitors crash sensors and controls deployment of airbags and seatbelt pretensioners. Ideal for workshops and experienced DIY mechanics looking to replace a faulty or crash-damaged airbag controller. Commonly searched by OE numbers such as 9650137080 and 602327400 — include these codes when searching to improve compatibility match.

Function and Symptoms

• Primary Function: Continuously monitors impact sensors, evaluates crash severity and triggers airbags/pretensioners when required. Stores fault codes related to the airbag system.
• Common Symptoms of a Faulty Unit: Persistent airbag warning light on the dashboard, stored crash or communication errors in fault memory, intermittent faults that clear and return, or total lack of communication with diagnostic tools.
• After a Deployment: Units that have recorded an airbag deployment may store crash data and often require replacement rather than simple reset.

Fitment

Fits: Citroën Xsara Picasso (models equipped with Autoliv airbag systems). Check the OE/product codes listed below to confirm mechanical and electrical compatibility with the vehicle’s harness and connector layout.

Technical Information

• Manufacturer: Autoliv
• Model: Citroën Xsara Picasso
• Product Codes: 602327400, 9650137080
• Other Numbers: 6556RA, NFP, (N68)

Installation Recommendations

• Always disconnect the vehicle battery and wait the manufacturer-recommended time before starting to work on the airbag system to avoid accidental deployment.
• Locate the unit (typically under the center console or beneath the passenger/dash area depending on model year) and carefully disconnect all electrical connectors. Take photos of connector positions to aid reassembly.
• Remove mounting fasteners and install the replacement unit in the original orientation. Ensure connectors are clean, dry and fully engaged.
• After installation, clear stored fault codes with a suitable diagnostic tool and verify system readiness. If the airbag light remains on, inspect wiring, sensors and grounding points before replacing the unit again.
• Replacement and any required initialization should be carried out by a qualified technician if you are not experienced with restraint systems — incorrect handling can be dangerous.

Why This Part Most Commonly Fails

• Collision Damage: Impact events can trigger deployment or damage internal circuitry, leaving the unit nonfunctional or storing unrecoverable crash data.
• Water Ingress and Corrosion: Moisture reaching connectors or the unit body can cause corrosion, short circuits or intermittent faults.
• Electrical Surges or Poor Grounding: Voltage spikes, jump-starting errors or bad grounds may damage the ECU electronics.
• Connector/Wiring Damage: Physical wear, rodent damage or poor repairs can break signal lines between sensors and the control unit.

Notes for Mechanics and DIYers

When sourcing a replacement, match OE/product codes (602327400, 9650137080, 6556RA) to ensure connector and functionality compatibility. Treat airbag ECUs as safety-critical components: follow service manual instructions and safety precautions strictly. This unit is supplied as described: fully functional.

Overview

This Airbag Control Unit (SRS ECU) manufactured by Autoliv is designed for the Citroën Xsara Picasso. Commonly searched by part numbers 602327400, 9659111980 and 6556RA, this unit monitors crash sensors and controls deployment of airbags and seatbelt pretensioners to ensure occupant safety. The description and codes make it easy for mechanics and DIY enthusiasts to find the correct replacement quickly.

Why This Unit Matters

The airbag control unit is the central element of the vehicle restraint system. It continuously evaluates input from crash and seat sensors and decides whether to trigger airbag inflation during an impact. Besides triggering, it stores crash event data and system fault memories which are required for proper diagnostics after an incident. Replacing a faulty or deployed unit is critical for restoring full occupant protection.

How To Replace (General Guide)

Replacement should be performed by an experienced technician or a competent DIYer familiar with SRS systems. Typical replacement steps:

• Disconnect the vehicle battery and wait at least 2 minutes to allow residual system energy to dissipate (follow manufacturer recommendations).
• Locate the airbag control unit (commonly mounted in the passenger compartment; locations vary by specification — under the center console or secured to the body structure behind trim panels).
• Remove necessary trim and fasteners to access the unit, then disconnect electrical connectors carefully — avoid bending pins and clean any corrosion.
• Fit the replacement unit, secure fasteners to the correct torque, reconnect connectors and reassemble trim.
• Use a diagnostic tool to clear SRS fault codes, verify system communication and perform any required initialization. If the unit has crash data or deployment history, it will not restore protection until the issue is resolved and proper replacement procedures are followed.

Installation Recommendations

• Always disconnect the battery before starting work and follow the vehicle manufacturer’s service procedures to avoid accidental deployment or damage to the unit.
• Inspect connector pins and wiring harness for corrosion or damage; repair any poor contacts before installing the new unit.
• After fitting, verify system status with a suitable diagnostic scanner capable of reading SRS data and clearing fault memories. Confirm no persistent faults remain and perform a road test as per workshop procedures.
• Keep track of part numbers when ordering; many mechanics search by the original codes (602327400 / 9659111980 / 6556RA) to ensure correct fitment.

Common Causes Of Failure

• Deployment During A Collision — Once airbags deploy, the control unit typically requires replacement.
• Water Ingress Or Corrosion — Moisture reaching the unit or connectors can cause malfunctions and intermittent faults.
• Electrical Surges Or Short Circuits — Battery issues or faulty wiring can damage internal electronics.
• Connector Damage Or Poor Contacts — Vibration, loose connections or pin corrosion lead to communication errors and SRS warnings.
• Age And Environmental Stress — Long-term exposure to heat, humidity and vibration can degrade components over many years.

Technical Information

• Manufacturer: Autoliv
• Model: Citroën Xsara Picasso
• Product Codes: 602327400, 9659111980, 6556RA
• Additional Numbers: 602327400 | 9659111980 | 6556RA

Notes For Mechanics And DIYers

This unit is intended for use in the Citroën Xsara Picasso SRS system. Ensure you have the correct part numbers when replacing the module. After installation, a diagnostic check is mandatory to confirm correct operation. If the vehicle shows an SRS warning lamp after replacement, re-check connections and scan for stored fault codes to guide troubleshooting.

This Autoliv airbag control unit (SRS ECU) is a direct-fit replacement option for Citroën Xsara Picasso models commonly referenced under part numbers 9652276980, 9650137080, 602327400 and marking 6556RA. The unit Manages Airbag Deployment Logic, Monitors Crash Sensors And Stores Crash Event Data. It Is A Critical Safety Component Designed To Interpret Signals From Impact Sensors And Trigger Airbags And Seatbelt Pretensioners When Required.

Fitment And Application

Compatible With Citroën Xsara Picasso Models. Frequently Searched By Part Numbers 9652276980, 9650137080, 602327400, 6556RA. Ideal For Professional Workshops And Experienced DIY Enthusiasts Performing Srs Repairs Or Module Replacement.

How The Unit Works

The Airbag Control Unit Continuously Monitors Input From Impact Sensors, Seat Occupancy Sensors (If Fitted) And Seatbelt Pretensioner Circuits. When A Crash Event Exceeds Predefined Thresholds, The Unit Issues Deployment Commands To The Relevant Restraint Devices. The Module Also Records Diagnostic Fault Codes And Crash Memories That Must Be Addressed After Any Collision.

Replacement Procedure (Overview)

• Park Vehicle On Level Surface, Engage Handbrake.
• Disconnect Battery Negative Terminal And Wait At Least 10 Minutes To Allow Capacitors To Discharge.
• Follow Manufacturer Fastener Locations To Access The Unit (Usually Under Passenger Seat Or Central Dash Area Depending On Year/Specification).
• Remove Electrical Connectors Carefully, Avoiding Damaged Locks Or Pins.
• Install Replacement Unit In Reverse Order, Ensure Correct Connector Seating And Secure Mounting.
• After Installation, Clear Fault Codes And Crash Memory Using A Compatible Diagnostic Tool. Verify SRS Indicator Behavior And Perform Full System Check.

Technical Information

• Manufacturer: Autoliv
• Model: Airbag Control Unit For Citroën Xsara Picasso
• Product Codes: 602327400, 9652276980, 9650137080, 6556RA
• Other Numbers: 9650137080 | 9652276980 | 602327400 | 6556RA

Installation Recommendations

• Always Disconnect The Battery Before Starting Work And Observe A Waiting Period To Discharge Residual Energy.
• Use Proper Torque Values And Manufacturer Fastening Procedures To Avoid Mechanical Stress Or Poor Grounding.
• Check Connector Pins For Corrosion Or Damage; Replace Damaged Clips Or Wiring As Needed.
• After Fitting, Use A Diagnostic Tool Compatible With PSA Vehicles (DiagBox/Lexia) To Clear Crash Memory, Read Srs Faults And Confirm System Integrity.
• If The Old Unit Shows Crash Memory, Do Not Reuse It Without Proper Clearing And Verification — Many Modules Require Resetting Or Replacement After Deployment.

Why This Part Fails Most Often

Airbag Control Units Typically Become Nonfunctional After A Collision Because They Record And React To Crash Events; Once Deployed, The Unit Often Must Be Replaced. Other Common Causes Include Water Ingress And Corrosion From Moisture, Electrical Surges Or Short Circuits, Damaged Wiring Or Connectors, And Mechanical Damage From Improper Handling. Environmental Degradation Over Many Years Can Also Lead To Intermittent Faults Which Trigger The SRS Warning Light.

Symptoms Of A Faulty Unit

• Srs/Airbag Warning Light Permanently Illuminated Or Intermittent.
• Recorded Crash Memory Preventing Airbag System Reset.
• Malfunction Of Seatbelt Pretensioners Or Airbag Deployment Circuits.
• Multiple Srs Fault Codes Present In Diagnostic Readout.

Replacement Of The Airbag Control Unit Should Be Performed By A Trained Technician Or An Experienced Diy Mechanic Comfortable With Safety Procedures. Proper Diagnostic Equipment Is Required To Ensure The System Is Restored To Full Operational Condition.