Description
Control Unit – Automatic Headlamp Leveling Unit for Citroën C4 and C5 II
This Valeo headlight control module is designed for automatic correction of Xenon headlamp aim on select Stellantis vehicles. It controls the leveling mechanism to keep the beam aligned under varying loads and driving conditions, improving night visibility and reducing glare for oncoming traffic. The unit is commonly identified by OEM part numbers and is often searched by these codes when technicians and DIYers look for direct replacements.
Technical Information
- Manufacturer: Valeo
- Model: Citroën C4; Citroën C5 II
- Product Codes: 9658054280; 6224K8
- Other Numbers: 6224R6; 6224R5; 00; NFP
Fitment And Compatibility
Primary fitment is Citroën C4 and Citroën C5 II with factory Xenon headlamps. The module may also be used on related Stellantis models that share the same headlamp electronics architecture. Because this part is commonly referenced by its product codes, searching or ordering by the listed numbers will increase the chance of matching the correct unit.
Function And Typical Failures
The control unit manages automatic headlamp leveling by receiving signals from vehicle ride-height sensors and driving small adjustment motors inside the headlamp assemblies. Its job is to maintain the correct beam angle when the vehicle load changes (passengers, luggage) and during dynamic driving. Failure Modes Commonly Include:
- Moisture Ingress And Corrosion: Water or condensation entering the connector or housing causes corrosion and electrical faults.
- Connector Or Wiring Damage: Broken pins, chafed cables, or poor connections lead to intermittent or permanent loss of function.
- Internal Component Degradation: Thermal stress, vibration and age can degrade electronic components inside the module.
- Related Component Failure: Faulty level sensors or adjustment motors may overload the control unit or produce fault codes that make the unit appear defective.
In service life terms, failures most often appear after many years of exposure to road conditions, typically in vehicles with high mileage or those frequently driven in wet or salty environments.
Installation Recommendations
- Safety First: Disconnect the negative battery terminal before beginning work. Avoid touching Xenon bulbs directly and follow standard high-voltage precautions when working near the Xenon ballast.
- Access: Depending on model year and body style, the control unit may be mounted on or near the headlamp assembly or behind the front bumper/wheel arch. Remove necessary trim or liners to reach the unit.
- Removal And Mounting: Unplug electrical connectors carefully, release retaining clips or screws, and transfer any rubber grommets or seals to ensure a watertight fit on reinstallation.
- Connector Care: Clean connector contacts and apply a small amount of dielectric grease to prevent future corrosion. Ensure pins are straight and fully seated.
- Initialization: After installation, check headlamp leveling operation. Some vehicles may require a diagnostic tool to clear fault codes or perform a leveling sensor reset/initialization—verify operation by cycling the leveling function and inspecting beam aim on level ground.
- Final Check: Verify that headlamp aim is within specification and that no warning lights or fault codes remain. Road-test at night to confirm correct beam behavior.
Why The Part Fails Most Often
Moisture and corrosion at connectors and inside the housing are the most frequent causes of failure, especially on vehicles exposed to winter salt or driven off-road. Vibration, poor sealing after previous service, and electrical surges from faulty wiring also contribute. Symptoms of a failing unit include headlamp leveling faults, warning lights, uneven beam height, or complete loss of automatic leveling.
When replacing the unit, use the listed product codes to ensure compatibility and follow the installation recommendations to maximize service life and restore reliable headlamp performance.
