
When the headlights are turned on at night, the daytime running lights will automatically turn off. Here are some detailed introductions about daytime running lights: 1. Many consumers believe that the main function of daytime running lights on cars is decorative, but in fact, this configuration plays a significant role in driving safety. 2. During daytime driving, they enhance the vehicle's visibility. Statistics show that using daytime running lights can reduce vehicle accidents by 12.4% and lower the probability of fatal crashes by 26.45%. 3. The above data is limited to some fog-prone climates abroad. In China, many people still regard them as decorative items.

Having driven for over a decade, I've noticed that daytime running lights automatically turn on for safety during the day and usually shut off at night. The principle is quite simple—most car models have light sensors. When it gets dark enough, the system turns off the daytime running lights and switches on the headlights. If you notice your daytime running lights still on at night, either the car's light sensor is malfunctioning, or you've manually turned off the headlights. However, newer models like Teslas are designed more intelligently—their daytime running lights automatically dim to parking light mode at night, saving energy while avoiding glare for oncoming drivers. It's advisable to check the dashboard indicators before driving at night to confirm the headlights are functioning properly.

We often encounter this issue in auto repair. Whether daytime running lights stay on at night depends mainly on the vehicle model year and design logic. Nowadays, over 90% of vehicles will cut power to the daytime running lights when headlights are turned on, as this is the most basic driving standard. However, some older American models may indeed have both daytime running lights and headlights illuminated simultaneously, primarily due to control module programming issues. If you're concerned about this, the most straightforward method is to start the vehicle without turning on the headlights, then use a flashlight to shine on the light sensor near the dashboard to see if the daytime running lights automatically turn off. Nighttime driving safety should always be the top priority - when lights are needed, don't rely solely on daytime running lights.

Just helped my neighbor adjust this feature last week. Normally, daytime running lights (DRLs) don't operate at night, as clearly required by EU regulations. After all, DRLs are angled slightly upward and could cause glare if left on after dark. Modern vehicle computer systems are quite advanced, automatically switching via ambient light sensors. Simply put, when it gets dark enough to trigger the headlights, the DRL circuit cuts power. However, be cautious when using high-pressure car washes, as water jets might short-circuit the sensor, causing abnormal DRL illumination. Vehicles with modified wiring may also disrupt the original logic. If unsure, consult the manual or observe lighting behavior of identical models when parked.


