Most modern vehicles come with sophisticated systems to detect problems within the vehicle. If you’re wondering what the brake lamp bulb fault error message means, you’ll get all you need to know in this article.
This error message is shown when the brake lights start malfunctioning. The lights could either be flickering or not working at all.
Functioning brake lights are a must-have on the road as it alerts other drivers behind that the car is decelerating or coming to a stop. If your brake lights aren’t working, the risks of accidents are high in traffic.
Fortunately, it isn’t a complex problem, and you can resolve it yourself!
Continue reading to find reasons why a car’s brake light may malfunction, followed by easy steps to fix them. Let’s get started!
More on Brake Lamp Bulb Fault – What Is It?

The ‘Brake Lamp Bulb Fault’ is an error message displayed in vehicles when an issue comes up with the brake lights.
Similar to the ‘Engine Check’ light, the purpose of this error message is to alert drivers of malfunctioning brake lights.
Although this error alert system is absent on old vehicles, issues with braking lights are nothing uncommon. The brake lights of a vehicle mainly depend on the electrical system.
If a car’s brake lights start to malfunction, this mostly indicates a blown fuse, faulty bulb, or loose electrical connections.
Brake Lamp Bulb Fault – Causes and Fixes
The first step is to figure out where it went wrong. If the problem goes too deep within the electrical system, it is recommended to visit a mechanic to resolve the issue.
That being said, here are the most common causes of a brake lamp bulb fault error and what you can do to fix them.
Faulty Brake Pedal Switch

The brake lamps of a vehicle are designed to shine bright immediately after the brake pedal is applied. This works via a switch that is located nearby the brake pedal.
As force is applied by your foot on the pedal, the pressure activates the switch, and then the brake lights turn on.
If the switch doesn’t work, it will not activate the brake lights even when the pedal is used.
Solution
The faulty switch has to be replaced. However, replacing switches incorrectly could lead to an unwanted mishap or even an accident.
Since the brake pedal is a sensitive component of the entire braking system, it is best to visit an expert.
But, if you know your way around cars, you might as well fix it yourself!
First, you’ll have to locate the brake light switch under the pedal. You may, or may not have to remove the pedal to get access to the switch.
Check if any wire connected to the switch is loose. If not, replace the faulty switch with a brand new one.
Blown Fuse

The most common reason for malfunctioning brake lights is blown fuses. Without a running fuse, even functioning brake lights won’t light up.
Once you’ve confirmed that the bulb and pedal switch is working, a burnt fuse is most likely the culprit.
A defective fuse could cause the brake lights to flicker or stop working entirely.
The fuses in a vehicle are found in a fuse box, which is usually located under the engine hood, or below the dashboard of a vehicle.
Solution
First, you’ll have to locate the defective fuse in your vehicle’s fuse box.
A blown or damaged fuse will be dark brown in color, and it may also have its wire snapped. Next, you should replace the damaged fuse with a brand-new one.
Defective Light Bulb

With prolonged usage, bulbs tend to lose brightness and eventually die out.
Once the bulb of a vehicle’s brake lights surpasses its life span, the brake lights stop working at some point.
Solution
You’ll have to disconnect the rear light assembly from the electrical line.
And then, you’ll either have to open the light casing or unscrew the bulb from its back.
Replace the defective bulb with a spare bulb or a brand-new set.
Malfunctioning Relay/Module
Modern automobiles depend a lot on computerized systems.
When the brake lamp bulb fault error is shown, it’s because the computer system detected something unusual. But the error could also show up when everything is working fine.
The culprit here would be a faulty relay or module that creates a bridge between the braking system and the computer.
Solution
This issue should be resolved by mechanics.
But if you’ve got sufficient knowledge and tools at hand, the first step would be to troubleshoot the module and check for the error codes.
Once you figure out which relay is malfunctioning, all you’d have to do is replace it with a new one.
Electrical Wiring Issue
The second most common reason for faulty brake lights is wiring issues.
Since the electronic system of a vehicle solely relies on wires, an improper connection with a sensor, switch, device, etc., could lead to wiring problems.
In the case of malfunctioning brake lights, we’re looking at wires that connect the brake lights, switches, as well as fuses.
A wire that is damaged (cut or burnt) or connected loosely will disrupt electricity to the brake lights.
Solution
Be sure to check if there’s a short circuit in the wiring first.
Then, you’ll need to locate where the wire is damaged or creating a short circuit.
Depending on what you see, you may have to replace the wire, repair it with insulation tape, or tighten loose connections.
The electrical wirings are very sensitive. If you aren’t sure what you are doing, your best bet would be to visit a mechanic.
Brake Fluid Level Dropped Below Normal
When the brake pedal is applied, a master cylinder pressurizes the incompressible brake fluid inside. This slows down the vehicle and eventually brings it to a stop.
In cases where the amount of fluid drops below the normal limit, the brake pedal doesn’t get the pressure that is needed for it to work. This can also lead to the brake lights not turning on.
Solution
First, you should check the brake fluid reservoir and see if it needs to be topped up.
If you find the level dropped below normal, add brake fluid till there’s enough in the reservoir.
Frequently Asked Questions
- What does brake lamp bulb fault mean?
It is an error message that indicates malfunctioning brake lights. This warning could originate due to faulty wiring, a defective brake light switch, a blown fuse, a damaged light bulb, or even due to low levels of brake fluid.
- Can I drive with my brake light on?
It is advisable not to drive a vehicle that has its brake lights on always as it may get dangerous. This also indicates an electrical issue in the braking system, and you should get it resolved as soon as possible.
- Can I drive without brake lights?
If you’re driving without brake lights, it could potentially lead to a collision as other drivers behind may not tell when you’re braking and slowing down. Moreover, it is illegal to drive without functioning brake lights.
- How many brake lights does a car need?
According to a regulation passed in 1986 by the NHTSA, at least three brake lamps are needed throughout the USA. A malfunctioning brake light poses safety hazards to you and other vehicles on the road as well.
- Are all brake light bulbs the same?
No, brake light bulbs are not universal, and it varies depending on the vehicle model. However, most vehicles make use of dual-filament bulbs. The thinner filament works as the tail light, while the thicker filament emits brighter lights and is used as the brake light.
- Are the brake light and the tail light the same bulb?
Most vehicles use dual-filament bulbs that serve as both tail lights and brake lights. One filament works for the tail light, while the thicker filament is used for the brake light. But, in some vehicles, there are separate circuits for each bulb, i.e., the brake light and tail light are not the same bulbs.
- How long does it take to fix a brake light?
Fixing a brake light is a relatively simple task, and it should not take more than an hour to complete. It may get complicated depending on the model, though, as there may be more wires to deal with.
- How long do rear brake lights last?
In most cases, traditional brake light bulbs can last at least 5 years before they start to lose brightness and eventually die out. On the other hand, LED brake light bulbs can last for more than 10 years.
Final Thoughts
With all of that being said, you should now know why the brake lamp bulb fault error message shows up and what you can do to fix it. Keep in mind that the braking system is a sensitive component of a car. If you aren’t sure about the technicalities, you should visit a professional mechanic.
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