Skip the auto shop - Our mechanics make house calls

What Does the Bulb Failure (Exterior Light Fault, License Plate Bulb, Brake Light Bulb) Warning Light Mean?

In order to help the driver maintain their vehicle, manufacturers have been using computers and sensors to monitor just about everything in a car. Modern cars are sophisticated enough now to detect when any exterior lights have stopped working. When a bulb goes out, the overall resistance in the circuit changes, which then affects the voltage for that circuit. The computer monitors the circuits for all of the exterior lights for any changes in voltage and then displays a warning light.

What the bulb failure light means

The computer will switch on the bulb failure warning light when it detects any non-normal voltage in any of the bulb circuits. If you see the light come on, check all of the bulbs to find the one that is not working. Be thorough when checking the lights as modern cars have quite a few that can turn on the warning light. Some harder bulbs to find include license plate bulbs, turn signals on the side mirrors, the yellow parking lights at the front of the vehicle, and the tail lights at the back that come on with the headlights.

When you find the bad bulb, replace it and the warning light should turn off. It is possible for false positives to occur in which case the entire circuit would need to be inspected for any damage.

Is it safe to drive with the bulb failure light on?

In most cases, the car is still driveable. Now this doesn’t mean you should ignore the light. The exterior lights are very important for warning surrounding drivers of your car’s position and actions. Having non-functional lights can also make you responsible for damages in the event of a collision.

If you need any help replacing bulbs or if the light won’t turn off, our certified technicians are always available to assist you.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

How to Find the Keyless Code on a Ford Explorer or Mercury Mountaineer
Many Ford Explorers and Mercury Mountaineers were manufactured with an option known as the Ford keyless entry keypad. Some models refer to it as SecuriCode as well. It...
How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...


Related questions

Q: What does it mean if my reverse lights are not working?

Reverse lights are an important safety feature that alert pedestrians, and other drivers, that your vehicle is about to move or is moving. If there is power at the reverse light bulb terminals when the vehicle ignition switch is on,...

Q: Windows open during storm & caused multiple problems

It is very likely that the water ingress from the windows being open during the storm has caused these malfunctions. Yes, the wiper switch input from the steering wheel is a coded input to the wiper motor assembly, which does...

Q: The driver side reverse light won't work, only the passenger side light works. I've changed all the bulbs and I still can't get it to come on.

I would suspect that that there is a problem with the socket for the light bulb. Corrosion will build up in the bulb socket and not allow power, or ground, to get to the bulb. If the bulb is okay,...