The function of the car's front lighting system
The core function of the car's front lighting system is to provide road lighting at night or in low visibility conditions, ensuring driving safety, and reducing interference to other vehicle drivers through anti-glare design. The following is the specific function analysis:
Core lighting function
The headlamps (headlamps) need to meet the requirement of clearly identifying obstacles within 100 meters. They are divided into two modes: high beam (long-distance illumination) and low beam (short-distance anti-glare). Common types include halogen lamps, xenon lamps and LED lamps.
Safety assistance function
Automatic light conversion system: It automatically switches between high and low beams through photoresistors and relays to prevent glare when meeting oncoming vehicles and enhance driving safety at night.
Turn signal lights: By flashing to indicate the intention to turn, they enhance road communication.
Design principles
Internal lighting should take into account both visual comfort and functionality. For instance, the design of dashboard lighting and reading lights should avoid interfering with the driver's line of sight.
The automotive headlamp system achieves the lighting function through optical design and electronic control. It is mainly divided into low beam and high beam modes and has functions such as automatic light adjustment and ambient light sensing.
Optical principles
Low beam mode: The filament is located in front of the focus of the mirror. After the light is reflected, it tilts towards the ground. The illumination distance is approximately 50 meters to avoid glare.
High beam mode: The filament is located at the focus of the reflector, and the light is emitted in parallel. The illumination distance exceeds 100 meters, but it needs to be manually or automatically switched to avoid dazzling oncoming vehicles.
Electronic control
Automatic dimming system: It detects the headlights of oncoming vehicles through a photosensitive tube and automatically switches between high and low beams.
Ambient light sensing: The sensor detects the external brightness and controls the headlamps to automatically turn on/off.
Structural composition
Bulbs: Halogen tungsten lamps, leds and other light sources. Xenon lamps need to be started at high voltage.
Mirror: Parabolic design focuses light, and the light distribution mirror adjusts the beam distribution.
New technology
Adaptive headlamps: By combining sensors to adjust the beam Angle in real time, they can adapt to complex road conditions such as curves.
Laser headlights: high brightness and low energy consumption, gradually applied to high-end vehicle models.
Headlamp system failure usually refers to the situation where the vehicle's headlights cannot provide normal illumination or have abnormal functions, which may affect driving safety at night and requires timely inspection. The causes of faults are diverse, and diagnosis should be carried out step by step from simple to complex.
Common causes of faults
Youdaoplaceholder0 Bulb problem : Bulb burnout, filament breakage or poor contact can cause the light to fail to light up or flicker, which is prone to occur after driving on bumpy roads.
Youdaoplaceholder0 circuit anomaly :
If the headlights on both sides do not light up, the fuse should be checked first.
Short circuit/open circuit: Aging of the circuit, loose or corroded plugs may cause poor contact.
Fault of the variable light switch or relay: The short-circuit method can be used to test whether the switch is damaged.
Youdaoplaceholder0 Control module and sensor failure (commonly seen in adaptive headlamp systems) :
Software or hardware failure of the headlight control module (GWM/BCM).
The connecting rod of the height sensor is damaged or broken, causing the light adjustment to malfunction.
The sensor or camera is dirty, affecting signal acquisition.
Youdaoplaceholder0 Power supply issues : Insufficient battery power, abnormal generator output voltage or poor grounding can cause the lights to dim or burn out frequently.
Diagnosis and treatment steps
Youdaoplaceholder0 initial inspection :
Observe whether the bulb is blackened or cracked, and try replacing it with a bulb of the same specification for testing.
Check the condition of the fuse and replace the blown one.
Youdaoplaceholder0 troubleshoot circuits and switches :
Connect the power supply terminal and the light terminal of the variable light switch using the short-circuiting method. If the light is on, the switch needs to be replaced.
Use a multimeter to measure the voltage and resistance of the line and find short circuit or open circuit points.
Youdaoplaceholder0 system-level diagnosis :
For adaptive systems, clean the sensors or cameras and check if the connecting rods are broken.
If the fault light remains on continuously, the fault code needs to be read through professional equipment for data re-matching or module calibration.
Youdaoplaceholder0 Professional maintenance : When it involves control modules, sensor calibration or complex circuits, it is recommended to contact an authorized service station to avoid the risk of self-operation.
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