DRL System: How It Works and Replacement Guide

Reviewed by

Anthony Harlin, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on February 25th, 2024

Reading Time: 5 minutes
Summary
  • DRL stands for daytime running lights. It makes your ride more visible during the day when passing through tunnels, under bridges, and others.
  • It automatically turns on when you start the engine. It works by relying on sensors to detect ambient daylight.
  • DRL costs between $20 and $80 to install daytime running lights.

Your vehicle’s automotive lights are crucial in ensuring your safety on the road. One of the most important lighting systems in your vehicle is called the daytime running light (DRL) system. So if it’s faulty, don’t think twice about replacing it. If you’re wondering what daytime running lights do and why they are important, then you’ve come to the right place.

What Are Daytime Running Lights?

Daytime running lights make your ride more visible during the day. Unlike high beam headlights, these lights aren’t there to help you see the road ahead. Instead, these lights keep your ride visible when passing through a tunnel, under a bridge, and other low-light passages.

How Does a DRL System Work?

DRL systems automatically come on when you turn on the ignition or when your ride is in motion. They rely on sensors to detect ambient daylight and determine when they activate. Daytime running lights run at a low power level compared to your high beam headlights.

DRL systems automatically come on when you turn on the ignition or when your ride is in motion.

DRL Light On Dash: What Does It Mean?

The DRL indicator light will usually activate once you turn on your vehicle, and it should turn off a few seconds after you remove your foot from the brake pedal.

If you notice that the DRL indicator light stays on longer than that, there’s a chance something is wrong within your DRL system. To be sure, consult your vehicle’s manual to have an idea about how your DRL system operates. On some vehicles, the DRL indicator light stays on the whole time the running lights are in use.

If you’re in the middle of the road and your car’s DRL warning light comes on, take your vehicle to an auto repair shop as soon as possible. The warning light means your vehicle’s computer has detected an issue within the system. More often than not, the problem can be traced back to bad DRL bulbs and circuits.

Are Daytime Running Lights Safe?

Daytime running lights keep vehicles visible during the day.

Daytime running lights keep vehicles visible during the day. Some studies even show that installing running lights can reduce the risk of accidents. As long as you follow state laws regarding automotive lights, there should be no danger in installing daytime running lights.

Low Beam Headlights vs. DRLs

Your low beam headlights and DRLs are close to each other, but that doesn’t mean that they share the same functions. 

Low beam headlights aid in road visibility, while DRLs make your vehicle more visible to other drivers. In some vehicles, these two types of automotive lights use the same bulb.

Daytime Running Light Issues

Here are some of the signs that could mean your indicator lights are faulty:

  • The DRL indicator light doesn’t turn on.
  • The DRL indicator light turns on, but the running lights don’t function.
  • Running lights are functioning properly when your vehicle is in motion, but they don’t turn off when you turn off the ignition.

If you’re starting to experience issues with your ride’s DRL system, check your owner’s manual to review how your DRL lights are supposed to work. Have your vehicle checked right away once you’ve confirmed that your DRL lights are malfunctioning.

Remember that having fully functioning automotive lights is essential for road safety. Also, you have to take into consideration that the DRL and low beam headlights are incorporated together. If you have issues with your low beam headlights, it will be very difficult to drive at night.

You have to take into consideration that the DRL and low beam headlights are incorporated together.

Anthony Harlin, ASE Certified Master Automobile Technician

What To Consider When Looking for Daytime Running Light Replacement

There’s a plethora of daytime running light replacements available on the market, so it isn’t that hard to find one for your ride. To help you make the right choice, here are some of the things to consider when buying DRL replacements:

DOT Compliance

All automotive lighting, signaling, and reflective devices are regulated by federal law. Before you buy your DRL replacement, it’s best to check if the bulbs you’re buying are certified by the Department of Transportation (DOT).

Quality

Your DRL system helps keep your vehicle visible during the day and ensures your safety on the road, so it’s only reasonable to get a top-notch replacement if it develops issues. Don’t settle for anything less than high-quality daytime running lights.

Compatibility

Make sure your DRL system replacement is compatible with your ride to ensure a fast and hassle-free installation. Check your vehicle manual or consult with a trusted mechanic before deciding on anything.

Brand

There are a lot of aftermarket brands that produce running lights. If you don’t have a go-to brand yet, you can read up on different brands available online. You can also go to product review pages to have an idea about other owners’ experience in installing and using the lights.

Once you’ve replaced your DRLs, make sure to follow regular maintenance checks. Having fully functioning automotive lights is essential for road safety. So aside from checking your DRLs, check the condition of other crucial automotive lights regularly as well. Have fun shopping for automotive lights and stay safe while on the road!

Get Daytime Running Lights for Your Vehicle Online

Daytime running lights make your vehicle more visible during the day, which can be helpful when you’re driving through tunnels or dark sections of the road. Moreover, daytime running lights are a neat accessory that makes a vehicle look modern. However, they can get damaged during unforeseen accidents. When this happens, CarParts.com is the place to get a great replacement.

Here at CarParts.com, we offer a wide range of parts and accessories for many vehicle makes and models. Our daytime running lights are made to OE specifications, ensuring that they’ll fit their intended vehicle model perfectly. Aside from offering separate daytime running lights, we also have a wide selection of headlights that have built-in daytime running lights.

Have questions about our parts? Don’t hesitate to chat with our friendly and helpful customer service team. Shop for a set of daytime running lights or headlights on CarParts.com today.

About The Authors
Reviewed By Anthony Harlin, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Tony Harlin is a Master Gas and Diesel Diagnostic Technician with over 18 years of experience. He works full-time at a large independent automotive shop as a driveability and repair technician working on all types of vehicles with a focus on diesels. ASE certifications include A1-A9, L1 and L2, as well as X1.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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CarParts.com Research Team and Anthony Harlin, ASE Certified Master Automobile Technician