Description
Immobilizer unit, one key fob with chip, engine control unit. All matched together from one vehicle. The car started, but the remote locking did not work. Probably a faulty battery in the remote. Originates from a Citroën C1 (2007).
This used set combines the engine ECU and immobilizer electronics together with a single key fob containing a transponder chip — all taken from the same vehicle and prepared for reinstallation. It is an economical and practical replacement for professional workshops and experienced DIY enthusiasts working on Citroën and Peugeot small cars. Supplied components reduce the time needed for parts pairing when compared with separate items purchased individually.
Compatibility and Application
Designed for Citroën C1 and Peugeot 107 models fitted with the 1.0 1KR EURO 4 engine family. Originally sourced from a Citroën C1 (2007). Intended for vehicles using an integrated immobilizer and ECU arrangement where the listed part numbers match the vehicle.
Technical information
- Manufacturer: Stellantis / Citroën / Peugeot
- Model: Citroën C1, Peugeot 107 (1.0 1KR, EURO 4)
- Product codes: 89780-0H020, 89780-0H021, 89740-0H010, 89740-0H011
- Additional numbers: 0261208702, 89661-0H022, 6580V7, 6252P3
How Replacement Works (Overview)
Replacement typically involves removing the old ECU/immobilizer assembly, fitting the supplied unit in the same mounting location, reconnecting all harnesses and securing fasteners, then performing the necessary data transfer or coding so the engine management and immobilizer recognise the keys. Exact removal locations and access vary by body trim and production year; always consult repair manuals for panel removal and connector locations.
Installation And Coding – Important
- The unit is used and is “paired” with the original vehicle (VIN/PIN/keys).
- Options to bring the unit into service:
- 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.
- It is recommended to be carried out by a technician 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
Disconnect the battery before starting work and allow capacitors to discharge. Keep work area static-free and avoid touching electronic contacts. Retain the original connectors and mounting brackets; transfer any brackets or shielding from the old unit if required. If cloning, ensure you have a verified backup of the original EEPROM/Flash. If virginizing and coding, perform the full telecoding and key adaptation sequence with compatible PSA diagnostic equipment to guarantee reliable operation.
Why This Part Fails Most Often
Common causes of failure include water ingress or corrosion of connectors, wiring damage, internal component degradation from heat and age, corrupted flash/EEPROM data, and key transponder or key fob battery faults that make the immobilizer refuse to allow engine start. In many cases a non-start condition is caused by a mismatch between immobilizer data and key transponder rather than a mechanically faulty starter or fuel system.
Who Should Fit This Part
Suitable for professional mechanics and competent DIYers familiar with vehicle electrical systems and immobilizer coding. Because coding or cloning is usually necessary to restore full functionality, shops with PSA diagnostic tools will complete the work fastest and with the least risk of residual faults.
If the part numbers listed in the Technical Information match your vehicle, this matched ECU + immobilizer + key set offers a cost-effective solution to restore starting and immobilizer functions while keeping original key compatibility when properly coded or cloned.
