Description
Power steering unit KOYO or JTEKT for Citroën C1 or Peugeot 107 or Toyota Aygo
This electronic power steering (EPS) control unit is a direct-fit replacement for Citroën C1, Peugeot 107 and Toyota Aygo models that use KOYO or JTEKT supplied steering modules. Designed to restore electric power assist performance, the unit controls motor torque and steering feel via internal sensors and electronics. Mechanics and experienced DIYers will appreciate the OEM-compatible connections and the fact that the part is commonly searched by its product numbers, making fast identification and ordering easier.
Technical Information
- Manufacturer: KOYO / JTEKT
- Model: Citroën C1, Peugeot 107, Toyota Aygo
- Product Codes: 89650-0H010, 400659, 1613433780
- Additional Numbers: EPS LH 6900000521, K91-00500, 225000-0080
Function And Benefits
The unit monitors steering torque and vehicle inputs to provide variable electric assist, improving fuel efficiency compared with hydraulic systems and enabling features such as stability control assistance. Replacing a faulty unit restores smooth, predictable steering effort, reduces noise or jerky steering motion, and prevents warning lights related to the EPS system.
Installation
General replacement steps for qualified technicians or experienced DIYers:
- Disconnect the battery before any work to avoid electrical damage or airbag faults.
- Remove under-dash panels or steering column covers to access the EPS unit (vehicle-specific access may vary).
- Unplug electrical connectors and remove mounting bolts. Keep track of fasteners and connector locations.
- Fit the replacement unit, secure with correct torque for the vehicle, and reconnect all plugs.
- Reinstall covers and reconnect the battery. Some models require steering angle sensor calibration or EPS adaptation.
After installation, run the required steering adaptations and fault code checks. In many cases coding or adaptation with manufacturer-level diagnostic tools is recommended to ensure full functionality (PSA vehicles: DiagBox/Lexia/PP2000; Toyota: Techstream or equivalent). Always follow the vehicle manufacturer’s service procedure.
Why The Part Fails Most Often
- Electronic component failure due to age, heat or vibration leading to loss of assist or erratic behavior.
- Torque sensor degradation or internal sensor drift causing incorrect steering assist calculations.
- Connector corrosion or water ingress (common in vehicles frequently exposed to moisture), causing intermittent faults or short circuits.
- Mechanical impact from collisions or heavy steering loads that damage the unit or its mounting.
Typical service life varies with usage and environment; faults are more common after heavy mileage or long service life (for example, from around 100,000 km onwards), but can occur earlier if exposed to contamination or electrical stress.
Recommendations For Mounting
- Always disconnect the battery before starting work and follow the manufacturer’s disassembly sequence to protect safety systems.
- Inspect wiring harnesses and connectors for corrosion or damage and repair as necessary before fitting the new unit.
- Secure the unit with correct fastener torque and ensure connectors seat fully with locking tabs engaged.
- Perform steering angle and EPS adaptations with a compatible diagnostic tool after replacement to clear faults and calibrate the system.
Compatibility And Notes
This unit fits Citroën C1, Peugeot 107 and Toyota Aygo models that use the listed product codes. Compare the product numbers on your original unit with the codes shown above before installation to confirm match. Replacement restores original electric steering functionality when the fault is within the EPS unit itself.
