What is the Daytime Running Lamp Module all about?

It can be difficult to identify oncoming traffic in certain conditions like fog, light rain, snow, and even on very sunny days with blinding glare. A system developed in the 80’s to automatically turn on a low-intensity light whenever a vehicle is in motion is known as daytime running lights, or DRL’s. These lights use reduced intensity high beam headlights, regular or reduced intensity low beam headlights, or marker lights for more prominence when driving. Lawmakers in Canada and in places overseas have implemented daytime running lights as law for all new vehicles since the 90’s, yet US lawmakers have not done so. Some automakers such as GM have voluntarily put DRL’s in their vehicles as an added safety feature.

The running lights are not the same as automatic headlights that turn on in dim lighting conditions, and typically DRL’s cannot be overridden. The DRL’s are controlled by the daytime running lamp module that receives a signal from the ignition to turn the running lights on when the vehicle is started. If the module short circuits internally the running lights may stay on indefinitely even with the ignition off, or they may not come on at all. If the wiring corrodes or breaks, the daytime running lights may not operate or operate intermittently.

Keep in mind:

• The daytime running lights are a safety feature. If your vehicle is equipped with daytime running lights, they are required to operate.
• Daytime running lights are a separate function from automatic headlights.

How it's done:

• The Daytime Running Lamp Module is verified that it needs to be replaced. Battery and tray are removed for access.
• The defective Daytime Running Lamp Module is disconnected and removed.
• The new Daytime Running Lamp Module is installed and connected.
• The battery and tray are reinstalled. The Daytime Running Lamp Module is tested for operation by starting vehicle and putting it in drive.
• The vehicle is road tested for proper operation of the Daytime Running Lamps.

Our recommendation:

There is no preventative maintenance or inspection you can perform on the DRL module. It should last the lifetime of your vehicle; however, it is an electrical component that can potentially quit operating due to environmental conditions. If it does fail, you will need to have one of our expert technicians replace it.

What common symptoms indicate you may need to replace the Daytime Running Lamp Module?

• Running lights don’t illuminate while driving during the daytime
• Running lights will not shut off after the ignition is turned off

How important is this service?

Although daytime running lights are a safety feature, they do not impede with the way your vehicle operates. If your daytime running lights are not working, you may receive a ticket in certain areas. Have the DRL module replaced at your convenience.