Daytime running lights are vital to your security. Studies have shown that DRLs make a vehicle more noticeable, reducing the chances of a collision. What if you don’t like DRLs?
What if you prefer to drive without them? You don’t have a choice in the matter. The Journal of Safety Research has a paper noting that daytime running lights are mandatory in Canada. This applies to many developed nations.
Therefore, traffic officers in some locations may fine you if they find you driving without functional daytime running lights. That begs the question. Why would DRLs stop working? You can blame one or more of the following:
1). The Bulb Burnt Out
Bulbs burn out all the time. Yours may burn out more frequently than usual because the bulb isn’t secure. If you keep driving through rough terrain at high speeds, the vibrations will break the filament.
If you drive too carefully to damage the DRL bulb, poor installation can produce similar results. Or maybe you have a defective alternator. Alternators power the car’s accessories. A faulty alternator can create voltage fluctuations. Voltage fluctuations can cause a bulb to burn out.
As you can see, burnt-out bulbs are not easy to diagnose. Something as simple as skin contact can shorten the bulb’s lifespan.
2). The Ambient Light Sensor Doesn’t Work
Turn the key in the ignition to the on position and shine a flashlight at the ambient light sensor. This component looks like a tiny half-dome inside (in the middle of the dashboard) or outside. It will turn the daytime running lights on or off depending on the ambient conditions.
If the sensor works, shining a flashlight at it will turn the DRLs on. However, it won’t activate the headlights. DRLs won’t work if the sensor is defective.
3). You Did Not Activate The DRLs
Go to the settings on the dashboard and look for the ‘Daytime Running Lights’ option. Is this option selected? The DRLs won’t work unless you enable this function. If you can’t enable the DRLs using the menu, you have a glitch in the firmware. Perform an update.
4). The DRL Module Is Defective
According to Your Mechanic, you can’t turn the daytime running lights off. Instead, the daytime running light module uses the information from the ambient light sensor and ignition switch to run the DRLs.
Therefore, a defective module will either prevent the DRLs from working or they will turn on and off erratically.
5). The Socket Is Burnt Out
If you’ve ruled out the bulb as a potential culprit, check the socket. 1A Auto has published a video where a mechanic takes the headlamp apart. In the video, the mechanic reveals the DRL socket and explains that it can corrode or burn out.
Once this happens, the light won’t work. If you can disassemble the headlamp, check the socket for burn marks or melted components to confirm your suspicions.
6). The Fuse Blew
If both DRLs have stopped working, you probably blew a fuse. Find the fuse panel and check the fuse layout. It will show you the DRL fuse. A blown or defective fuse will prevent the daylight-running lights from illuminating.
On the surface, this problem is the least challenging because fuses are cheap and easy to find. But what if you install a new fuse, and it also blows? You should find out why the old fuse blew, especially if every fuse you add meets the same fate.
7). The Cable Broke
DRLs have wires that meet their electrical demands. Without those wires, the lights won’t work. Pull the light apart and check the connectors. Are they loose? Do they give way when you gently tug on them? Are the cables frayed? Do they have burn marks?
Corrosion and moisture can blow a fuse when they invade the wiring. But a light’s wiring issues may not necessarily originate from behind the headlamp. You need an expert that understands electrical wiring in automobiles to scrutinize your vehicle carefully.
How To Fix BMW Daytime Running Lights That Is Not Working?
If you live in a location that mandates the use of daytime running lights, you should fix them before you attract hefty penalties. The following solutions may help:
1). Fix The Loose Connectors
Wiring issues have simple solutions. The challenge is identifying the loose connectors and frayed wiring. Remove the light assembly and inspect the connectors. Are they loose? Tighten them. If you see frayed wires, replace them.
Don’t tug at the wires with so much force that you loosen or damage them. Be gentle. But again, finding the loose connectors is not easy.
2). Remove The Light Bulb
Remove the light assembly and inspect the bulb. If it’s burnt out, replace it. You can access most bulbs by rotating them counterclockwise and pulling until the bulb comes out of the socket.
Use the manual to determine the correct specs for a replacement bulb. The wrong bulb may burn out immediately or refuse to work. Keep in mind that bulbs have limited lifespans. They will eventually die of old age.
Therefore, don’t assume that every burnt-out bulb failed because of some other malfunction in the vehicle, such as a faulty alternator.
3). Replace The Fuse
If one light has failed, you have a burnt-out bulb. But if both lights have failed, you blew a fuse. Use the manual to identify the BMW’s fuse box. The fuse layout is on the back of the fuse box cover.
The diagram will show you the fuse that controls the bulbs. Replace the fuse, but only if it has blown. A blown fuse has a broken filament.
4). Replace The Socket
Daytime running lights can damage the socket by running all day. They can generate enough heat to melt the contacts. Ask BMW’s customer support personnel to recommend a replacement electrical socket. Don’t bother fixing a burnt or melted socket.
5). Clean The Water
Technically, the light assembly is sealed. The housing will keep water out. However, condensation can still accumulate inside. Try to clean this water before it damages the light. Otherwise, it may cause a short circuit, forcing you to replace the wires, bulbs, and fuse.
Water can attract rust. Like the moisture, try to remove the rust before it causes further damage. This is why regular maintenance is important. Your mechanic will identify the moisture and corrosion during maintenance.
6). Replace A Defective Ambient Light Sensor
Some light sensors will stop working if you cover them with obstructions. If the sensor seems fine, check the daytime running light module. You will find it in the engine compartment.
But the exact location may vary depending on the BMW. Test and replace the module where necessary. Like the water and corrosion, your mechanic will check the DRL module during maintenance.
Cost To Repair It
The cost will depend on the part you want to repair. For instance, an ambient light sensor may cost you $300 or less. You will spend a similar amount to install new daytime running lights. Although, Kelley Blue Book expects you to spend a whopping $750 if you include labor fees.
The bulbs, fuses, and wires are the cheapest parts to replace. This assumes that you need replacement parts. For all you know, tightening a few connectors is enough to fix the issue.