Why Does My Car Accelerate When I Brake, speedometer of a car

Why Does My Car Accelerate When I Brake

Imagine the heart-pounding moment when you press the brake pedal, expecting your car to obediently slow down, only to feel an unexpected surge of acceleration. Then you might start thinking, “Why does my car accelerate when I brake?”

Sudden car acceleration can be caused by driver error, mechanical issues like a stuck throttle or fuel system problems, electronic malfunctions, floor mat interference, or vehicle recalls. It is important to understand the problem and get the car inspected for the underlying cause.

As someone who faced this problem, I was able to find the most common reason through deep research. If you’ve ever found yourself gripped with concern over your car suddenly taking off like a rocket, then stay tuned. In this article, I’m going to unravel the truth behind unintended acceleration.

What is the Mechanism Used in Acceleration?

There are two different techniques used in older and newer vehicles for acceleration.

Older vehicles

Accelerator cable is broken

In older cars, the accelerator pedal was directly connected to the throttle via a cable. Pressing the pedal would pull the cable, opening the throttle and allowing more air into the engine.

What Is the Reason for Unintended Acceleration in Older Vehicles?

If a vehicle exhibited uncontrollable acceleration, it was usually due to a stuck throttle cable.

How to Fix a Stuck Throttle Cable?

The remedy was relatively straightforward: lift the throttle manually by placing a foot beneath the pedal to bring the vehicle to a halt. Subsequently, the cable could be lubricated or replaced to restore normal operation.

Newer vehicles

Fast forward to the present, and you’ll notice a fundamental change in how acceleration is controlled. In modern cars, accelerator cables are gone. They are replaced by a sophisticated system of computer sensors and electric motors.

How does The Accelerator work in Modern Cars?

Accelerator pedal sensor, removed, this is on hand

When you press the accelerator pedal in these cars, you are essentially manipulating a computer mouse at the top. The computer sensor relays the pedal’s position to the engine control unit (ECU), which, in turn, commands an electric motor to adjust the throttle accordingly. This electronic system offers greater precision and control over acceleration.

Is There No Intended Acceleration in Modern Cars?

However, the development of sophisticated computer systems also poses the risk of unintentional acceleration. But it is a rare situation when compared to older ones.

How to Handle Unexpected Acceleration in Never Models?

The key to handling unintended acceleration is to remain calm and take decisive action. Instead of panicking, simply shift the car from “Drive” to “Neutral.” By doing so, you disengage the engine from the transmission, effectively severing the power transfer to the wheels. In neutral, the engine cannot supply power to accelerate the vehicle any further. It’s a simple and effective solution.

Note: Some individuals suggest turning off the engine entirely. However, this approach can lead to a loss of power brakes and power steering, potentially complicating matters further. Shifting to neutral is a safer alternative, as it immediately halts the acceleration without compromising other crucial systems.

How to Fix Unintended Acceleration in Modern Cars?

If you encounter unintended acceleration in a modern vehicle, it’s advisable to have it inspected and repaired by a qualified professional.

What Should I Do If My Car Accelerates When I Brake?

Here is how to deal with sudden acceleration when braking.

Step 1: Shift to Neutral

The most effective and immediate action to take is to shift the car into neutral. By doing so, you disengage the transmission from the engine, allowing the wheels to rotate freely without the influence of engine power. This will allow you to safely brake and steer out of traffic, gradually bringing the vehicle to a stop on the side of the road.

Step 2: Apply Brakes

Once in neutral, it’s crucial to focus on skillful braking and steering to navigate your way to safety. Apply consistent pressure to the brake pedal, employing measured and deliberate movements. Be mindful that the engine’s wide-open throttle may require more force than usual to achieve the desired deceleration.

Step 3: Steer Safely

Concurrently, maintain an acute awareness of traffic conditions, deftly maneuvering the vehicle toward the side of the road or any other safe area, well away from the path of oncoming traffic.

Turning off the Ignition Key: The Last Resort

While shifting into neutral is typically sufficient to regain control during unintended acceleration, there may be exceptional circumstances where the throttle stubbornly persists despite this maneuver. In such rare cases, resorting to turning off the ignition key could be contemplated as a last-ditch effort.

Important Note Again: Certain vehicles equipped with electronic power steering may compromise steering control when the engine is disengaged. It is of utmost importance to evaluate the situation meticulously before considering this measure.

Other Causes of Sudden Acceleration

Misapplying the pedalsDriver error in pressing the wrong pedal (brake instead of gas or vice versa)
Mechanical MalfunctionRecalls on certain car models due to unsecured floor mats that obstruct proper brake pedal usage
Electrical MalfunctionElectrical problems causing the throttle to open when the car is in “P” mode, leading to acceleration
Shifter LinkageWorn-out shifter linkages in older car models may cause resistance and unintended acceleration when shifting gears
Poor MaintenanceTrial-and-error maintenance by untrained mechanics leading to additional mechanical problems, including unintended acceleration
Vehicle ProgrammingModern vehicle features, such as brake-ignition-shift lock systems and in-car computer networks, reducing the likelihood of unintended acceleration

Can I Stop a Car with Full Acceleration?

First and foremost, it is essential to recognize that even with the throttle held wide open, the brakes still have significant authority to slow down and stop the vehicle. Numerous tests and demonstrations have proven that brakes can overpower a fully accelerated engine. This knowledge provides reassurance that you have a reliable means of deceleration.


What are the situations that could lead to unintentional acceleration?

Instances of unintended acceleration can occur due to various factors. Engaging in routine driving actions such as shifting gears, disengaging cruise control, or applying the brakes has the potential to alter the electrical current within a vehicle. This alteration, in turn, may trigger malfunctions that manifest as sudden acceleration and give rise to a range of related issues.

What controls acceleration in a car?

The accelerator, also known as the gas pedal, is situated adjacent to the brake pedal on the vehicle’s floor. Its primary function is to control the amount of fuel injected into the engine, thereby determining the car’s speed and acceleration.

How to improve car brake efficiency?

Here are 10 concise points to improve car brake efficiency:

  1. Regular maintenance
  2. High-quality brake components
  3. Brake fluid flush
  4. Brake cooling
  5. Avoid overloading
  6. Smooth driving technique
  7. Avoid unnecessary brake usage
  8. Tire maintenance
  9. Brake system upgrades
  10. Professional inspection

What does a brake booster do?

The brake booster plays a vital role in enhancing the hydraulic pressure transmitted to the master cylinder by intensifying the force exerted on the brake pedal. This component is of utmost importance in ensuring the efficiency of braking in every vehicle, significantly contributing to overall safety.


Experiencing car acceleration even when braking is a nerve-wracking situation. So, it is important to know, as knowing how to respond can save lives. Remember to remain calm and focused if you encounter such an event. Only consider turning off the ignition key as a last resort. By following these steps, you can effectively address unintended acceleration and ensure your safety on the road.

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