Description
Airbag control unit for Citroën C2, C3 and C3 Pluriel.
This airbag control unit (SRS ECU) is a direct-fit safety module suitable for Citroën C2, C3 and C3 Pluriel vehicles. Designed for professional mechanics and experienced DIYers, this unit monitors crash sensors, controls airbag deployment and works with seatbelt pretensioners to protect occupants in a collision. Commonly searched by part numbers 9656889080, 654583, 654584 and 654691, the module is a key safety component for Stellantis vehicles and is often replaced after impact or when SRS fault codes are present.
Technical Information
- Manufacturer: Stellantis / Citroën / Peugeot
- Model: Citroën C2, Citroën C3, Citroën C3 Pluriel
- Product Codes: 9656889080
- Additional Numbers: 654583, 654584, 654691
Function And Benefits
The unit continuously evaluates inputs from accelerometers, impact sensors and seatbelt switches. When a collision threshold is exceeded, it triggers airbag deployment and seatbelt pretensioners. Replacing a faulty or deployed control unit restores correct SRS function and clears persistent airbag warning lights when properly installed and coded. For workshops, having the correct part numbers on hand speeds diagnosis and repair.
Installation Recommendations
- Disconnect the negative battery terminal and wait at least 10 minutes to allow the SRS capacitors to discharge before starting work.
- Locate the unit—typically mounted under the dashboard or center console—remove surrounding trim carefully to avoid damaging connectors and harnesses.
- Unplug connectors using the locking tabs, remove mounting bolts, and replace with the new unit. Ensure all connectors are fully engaged and locking clips are intact.
- After mechanical installation, perform diagnostic checks with a suitable tool (e.g., manufacturer-level scanner such as DiagBox/Lexia or equivalent) to clear fault codes and, if required, program or match the unit to the vehicle.
- Verify SRS lamp extinguishes and run a final check of related systems (seatbelt sensors, airbag circuits). Observe all static-electrical precautions when handling airbag components.
Most Common Failure Reasons
- Crash Deployment: The most frequent reason for replacement is activation during an accident; the unit can store deployment data and often must be replaced afterward.
- Water Ingress And Corrosion: Moisture penetrating the cabin or dashboard area can corrode connectors or internal circuitry, causing faults.
- Electrical Surges Or Short Circuits: Voltage spikes from jump-starts, battery faults or wiring damage can damage internal electronics.
- Connector Damage Or Poor Grounding: Loose, corroded or damaged connectors commonly produce intermittent faults and fault codes.
- Internal Component Failure: Aging components or manufacturing defects can lead to unit malfunction; SRS warning lamp and stored fault codes usually indicate the problem.
This airbag control unit is a safety-critical part. When replacing it, follow manufacturer procedures, use appropriate diagnostic tools for post-installation checks and ensure all repairs restore full SRS functionality before returning the vehicle to service.
