6 Reasons Your Car Accelerates on Its Own [Fixed]

Last Updated on April 22, 2022 by Auslar Chukwuka Chimuanya

Your car accelerates on its own for some annoying reasons that can be fatal. Thus, if you have this problem, you want it fixed ASAP.

The typical experience when your car is accelerating by itself is that the engine RPMs will increase, and so will the speed.

This will happen severally, not constantly but intermittently. A diagnosis may be able to indicate what the problem is, but in the meantime, this article explains the possible causes. For some of the causes, you may not even need a mechanic to stop your car from accelerating without matching the gas.

car accelerates on its own

What does unintended acceleration mean in a car?

Unintended acceleration is considered a glitch involving a car that accelerates on its own without the driver’s input. Sometimes, you would experience a loss of braking when this happens. This means you have no control or whatever over the situation, which can cause an auto accident.

Read also: stiff steering wheel is also dangerous: how to fix

A malfunctioning vehicle electronic system will prevent the mechanism responsible for controlling the power train of a car from operating properly.

Unintended acceleration can be dangerous in newer vehicle models as a result of malfunctioning throttle control mechanisms. Of course, this happens suddenly while the car is in motion without hitting the gas pedal.

Apart from suddenly accelerating without touching the gas, you may also be unable to use the brake. It can also be difficult to return the vehicle to idle if it is already in gear.

Another common occurrence is that you cannot control the car at this point.

Sudden unintended acceleration, as the name implies, happens at any least expected time. However, it occurs more commonly when you match the brakes, shift gears, or change to cruise control.

The electrical current of the car is affected by this sudden change and can cause the car to accelerate on its own without your input.

Reasons your car accelerates on its own and how to fix

There are a few possible causes of a vehicle accelerating on its own. Let’s consider the major causes and what you can do to fix them:

  1. Failing throttle body

A car accelerating on its own without the driver’s input is commonly caused by a malfunctioning throttle body. If the throttle plate of your car sticks, it cannot return to the correct position, so the car will accelerate as a result.

How to fix

The common fix for a failing throttle body is to Inspect it to see if it is sticking. Clean dirt or debris off the throttle body if dirty. In extreme cases, you may need a replacement throttle body to stop your car from suddenly speeding up on its own.

  1. Pedal sticking to the floor mat

The pedal sticking to the floor may sound impossible but it happens, and many drivers have experienced it.

Read also: explanation for a car that keeps turning off while in motion

The pedal getting stuck on the floor mat is not a common cause of an automatically accelerating car. Nonetheless, a loose floor mat may slide up on the accelerator pedal or even jam between the pedal and center panel of the vehicle. This causes the pedal to remain in one position, so the car suddenly accelerates on its own.

How to fix

Lift the floor mat to check if it is pinning down the pedal.

  1. Faulty idle air control

The IAC (Idle Air Control) could be the reason your car accelerates on its own. IAC actuator or idle air control valve is located in fuel-injected vehicles and is responsible for controlling the idling rotational speed of the car engine. In a carbureted car, an idle speed control actuator is also used.

IAC also works with the ECU (Electronic Control Unit) of the car to electrically regulate airflow to the engine for smooth idling. If faulty, your car will accelerate on its own.

How to fix

The solution is to remove and clean the IAC to stop the vehicle from accelerating when you do not use the brake. Use carb cleaner to clean the inside and get rid of the carbon and gunk.

  1. Dirty mass airflow sensor

A dirty mass airflow sensor is a device in the engine that tells your computer system of the car the amount of air entering the engine.

The reason your vehicle accelerates on its own could be a mass airflow sensor. This sensor gets dirty, causing a surge in condition and excessive fuel consumption. Meanwhile, here is a low fuel consumption Toyota.

How to fix

You can fix a dirty mass airflow sensor by cleaning it. In some cases, a replacement is needed to stop the problem.

  1. Vacuum leak

The culprit could be a vacuum leak. This is, however, easy to inspect with a bottle of starter fluid.

The vacuum in a car is the difference in air pressure “between the inside of the intake manifold and the outside atmosphere”.

The difference in pressure creates suction and assists with drawing air into the car’s engine. Meanwhile, for a gasoline engine to run, an engine vacuum is needed.

If your vehicle leaks vacuum pressure, the engine will receive excessive air, creating an imbalance in the air and fuel mixture used for generating engine combustion.

The excess air can cause your car to accelerate to sputter or even refuse to respond when you attempt to pick up the speed.

  1. Falling vacuum hose

If you have a fuel-injected car, a failing vacuum hose could be the reason your car accelerates on its own.

A vacuum hose in a car is the flexible tube used for transmitting vacuum power throughout the car. It helps to maintain the proper pressure within the engine, allowing the fuel, the air, and the spark to operate in tandem. If faulty, your car will accelerate on its own.

It can be difficult to spot a pinhole in a vacuum hose. The suspect components are failing fly-by-wire speed sensors between the throttle position sensor and accelerator pedal.

What to do if your car accelerates by itself without your input

What do you do when your car accelerates on its own

This is a problem you need to have fixed as it can cause a severe auto accident. Do the following when your car suddenly starts accelerating on its own:

  1. Do not panic

Staying calm may be difficult when your car suddenly accelerates without your input or matching the gas. You need to stay calm to be able to get the car off the busy road.

Some drivers may already be yelling at you, not knowing that it is not your fault. Since this problem can happen at any unpredictable time, you need to immediately review the cause to see if you can fix it yourself.

  1. Match the brakes

The brake may not be immediately responsive when the car suddenly accelerates. However, the moment you gain control of it again, hit the brakes to maximize the vacuum power assist.

  1. Put the car in neutral

Put the car in neutral while bringing it safely off the road. Ensure to go in a straight line. While switching the lanes, be careful to manage your movement properly. If the car refuses to shift to neutral, turn it off.

The key should be in the ignition to stop the steering wheel from jamming when the engine turns off.

  1. Seek help

When the car is parked safely, contact a mechanic to diagnose and fix the problem. Some certified mechanics may be able to visit your current location, home, or office to diagnose and repair the vehicle.

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