Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Bi-Xenon Headlight System
- Left headlamp control unit (LHCU)/Right headlamp control unit (RHCU) (vehicles with active headlamps only)
- Motor, headlight levelling
- Lamp contact, high voltage
- Bi-Xenon lamp
- Internal headlight edge
- Motor, high and low beam
Bi-Xenon, a headlight system with moveable reflector, is based on gas discharge technology. The system combines high and low beam into the same lamp.
Due to legal requirements (regarding low beam) for this type of lamp, the vehicle must be equipped with automatic headlamp levelling.
Xenon vs. Halogen
Xenon:
- higher color temperature, which produces a whiter light
- better reflection of road signs and road markings
- lower power consumption (approx. 65% lower).
Information
- Daylight has a color temperature of about 5000 °K. The closer to natural light, the less strain on the eyes. Standard H4 bulb: 3200 °K. Volvo's gas discharge bulb: about 4200 °K.
- With the Bi-Xenon system, high and low beam generates the same light color. The human eye thus has an easier time adjusting to switches between high and low beam.
NO RELATED
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.