Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. What Does the Bulb Failure (Exterior Light Fault, License Plate Bulb, Brake Light Bulb) Warning Light Mean?

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

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.


More related articles

How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...
P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP)...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...

Related questions

Q: What replacement bulbs do I need?

From your headlights to your brake lights, map lights and rear cargo area light, you’ll find bulbs in use throughout your car. Over time, those bulbs will blow, although they should last for many years without having to replace them....

Q: After starting SUV, 4 indicator lights come on

There are several reasons that this could happen. A system voltage dip or spike can cause all of these systems to illuminate their indicators or a fault that compromises the drivability of the engine such a mass airflow or oxygen...

Q: Brake light bulb sockets fried & melted

Hello there, when bulbs are required to be replaced multiple times like this, there are a few common causes. The most likely would be moisture in the taillight, short-to-power, wiring damage, or a faulty taillight assembly. Generally this is seen...