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Sudden Unintended Acceleration: Causes and Solutions

ByTsukasa Azuma-March 01, 2024

Acceleration works like fire – a cruel master and a good servant. Acceleration can be joyful, but when you don’t want to, it can turn into a nightmare. Sudden unintended acceleration is the most deadly defect in the history of automation.

It happens when the car’s electronics cause the throttle to expand wide open. It makes it difficult for the driver to return the car to idle if it remains in gear.

Further, it severely limits the ability of the brakes to bring the vehicle under control – leaving the driver at the mercy of a fast running uncontrollable car.

Millions of people injure and die because of a suddenly accelerated vehicle issue, in today’s world.

What Causes Unintended Acceleration?

The primary reason for sudden unintended acceleration while braking is the malfunction in the electronics, controlling the vehicle’s power train.

The cases of the throttle control mechanism have risen to a next level since the introduction of throttle control mechanism in modern vehicles.

Indubitably, advancement in vehicles has made the cars safer, but the modern electronics increase its complexity. However, the possibility of malfunction remains high and sudden acceleration is still a major issue to deal with.

When does Sudden Unintended Acceleration Occur?

Sudden unintended acceleration can cause car breakdown (Photo source: Depositphotos)

There is nothing fixed – a sudden acceleration can happen anytime. Because of certain design changes in vehicle electronics, most accidents happen when the vehicle is under way.

Shifting gears, disengaging the cruise control, applying brakes, etc. gives rise to sudden acceleration. These common conditions cause a disturbance in the electrical current that prompts a dangerous malfunction.

Solutions For The Sudden Unintended Acceleration

Controlling the car with sudden unintended acceleration requires some knowledge – it may not be possible for a neophyte. Here are some ways to deal with it:

1. Use Brakes

Although, it is a natural reaction, yet using the throttle emergency is imperative to use brakes as hard as possible. Do not keep pumping the pedal instead keep it steady.

The brakes will need more force than usual, so, muster more force than you can. The car won’t slow down at a normal speed but brakes are more powerful than the car’s engine, so eventually, the brakes will win.

2. Shift to Neutral

This is the best option in an emergency. In case, the throttle is wide open, the engine might alarm high. Do not worry about throbbing the motor as most electronic limiters comes with automatic spinning, which controls the disturbance due to the sudden shift.

3. Turn off the Engine

Ways to stop sudden unintended acceleration (Photo: web.sonoma.edu)

By now, your car is well under control. But to be safe, shut off the engines. Some modern cars have push-button starters, which you may have to hold for 2-3 seconds to stop the engine.

While doing so, be careful as the break-pedal pressure may slightly increase. In order to maintain safety, pull the car off the road and call for help.

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FAQs on Sudden Unintended Acceleration (SUA)

  1. How can I prevent Sudden Unintended Acceleration?

To reduce the risk of SUA, ensure regular vehicle maintenance, promptly address any warning lights or unusual behaviors in your vehicle, and be attentive to recalls or safety-related notices issued by the manufacturer.

  1. What should I do if my vehicle experiences SUA?

If your vehicle suddenly accelerates uncontrollably, prioritize safety. Shift into neutral, apply the brakes firmly, and steer to a safe location.

Turn off the engine only if it’s safe to do so. Seek immediate professional inspection and report the incident to the manufacturer and relevant authorities.

  1. Are there recalls related to SUA?

Manufacturers occasionally issue recalls related to Sudden Unintended Acceleration concerns. Stay informed about recalls by regularly checking the National Highway Traffic Safety Administration (NHTSA) website or contacting your vehicle manufacturer.

  1. Can Sudden Unintended Acceleration be caused by driver error?

Yes, in some cases, these incidents can be attributed to driver error, such as pedal misapplication, where the driver mistakenly presses the accelerator instead of the brake pedal. Proper driver training and attentiveness are essential for preventing such errors.

  1. Are there any legal actions or lawsuits related to SUA?

There have been legal actions and lawsuits involving the incidents against vehicle manufacturers.

These cases often seek compensation for damages related to accidents allegedly caused by SUA. Consult with legal professionals for specific information on ongoing cases.

  1. How are manufacturers addressing Sudden Unintended Acceleration concerns?

Manufacturers continuously work to enhance vehicle safety and address these concerns through improved technology, design, and rigorous testing. They may also issue recalls and implement software updates or modifications when necessary.

  1. Is there technology to prevent SUA?

Modern vehicles are equipped with safety features like brake override systems and electronic throttle control that can help mitigate incidents. 

However, no technology can guarantee absolute prevention, so driver awareness and maintenance remain crucial.

  1. Where can I report a suspected Sudden Unintended Acceleration incident?

If you experience or suspect a Sudden Unintended Acceleration incident, report it to the vehicle manufacturer, the National Highway Traffic Safety Administration (NHTSA), and your local authorities. This helps ensure proper investigation and potential resolution of the issue.

Check out this video from Scotty Kilmer to learn how to stop unexpected car acceleration!

Overall, to win a sudden unintended acceleration situation, do not panic and stay calm. To face the dangerous situation, gather professional knowledge and learn some more tips. After all, safety comes first!

Tsukasa Azuma is an awesome car blogger of Car From Japan. He owns a car repair shop at downtown Osaka, and he put all that experience to good use in his sharing posts. Tsukasa’s blog is one of the best resources for information about keeping your favorite imported car running smoothly. Moreover, because of being passionate to learn about the recent happenings in auto industry, he doesn’t only provide great car maintenance tips, he also always updates latest trends in among car brands and share them in his own interesting viewpoint.

Comments

Thomas10:41 September 05, 2019
Reply

I had a Subaru Forester, 2018 model. I pulled up at the kerb to do a right angle carpark. I stopped the car at the kerb. I had my foot on the brake and was moving the gear lever from drive to park to turn the car off when the car took off with enormous acceleration. The car collided with a building only 3 meters away. Apart from front end damage, almost all of the airbags were triggered. Fortunately I still had my seatbelt still on. Subaru took the ECU and Eyesight system out of the the car and had it analysed. They came back with an email saying that it was my fault as I had my foot on the accelerator. I may have put my foot on the accelerator after the car took off but this does not explain the magnitude of the collision. I have done my own tests on another Subaru and found that the maximum velocity I could achieve over three metres (from stop position) was about 8 kph. It’s not possible to write off a car at this speed. The threshold for airbags going off is 20 kph. A person in the building felt the building shake and commented on the enormous torque that the car must have achieved. For me, it felt like I was in a drag race over three metres. I believe that the velocity at impact was at least 20 kph. I have read that sudden acceleration is caused by electrical leakage across the drive system which causes an open choke situation creating very high RPM and sudden unexpected acceleration. I’ve described my own test to Subaru and asked them to do their own analysis and to provide me with a report and the data from the ECU such that i can do further evaluation. They have said they won’t provide the data as this is commercial and confidential. I’m open to suggestions as to the next step I should take.

UGUR Akar23:55 February 26, 2019
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By pass all firing, fueling realeted computirez device & sensors.Leave the realeys alone.Now you have electrical mechanic power supply delevery system.You just need can of w40.

JM Mitchell18:21 February 18, 2019
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02-18-19
I don’t know how many are still reading this, however I feel compelled to share the “sudden unintended acceleration” experience that I had last Tuesday 02-12-19. I slowed to pull into my driveway (slight downward incline toward my garage), and gently applied the brakes. My 2014 Mercedes GLK 4Matic shot forward faster than a roller coaster car on the Millennium Force speeding down from it’s highest point! I can still feel the shock of helplessness as my car crashed through my closed garage door and into the west corner of my garage. It accelerated so fast that it took out drywall and support boards between my office and garage and both of the rooms’ walls to outside. My right wheel was hanging outside 3 feet above the ground. I cannot believe that I jwas not injured as I just opened the door and stepped out. Debris was everywhere inside and outside of the garage. I just stood there looking at my car like a deer in headlights! Learned two days later that my car was totaled. I am still reeling from the experience. Had never heard of SUA but thankfully, I have a learned friend who shared the information with me. NOTHING about my car’s performance warned me that this could occur. Thank you all for sharing your experiences so that others will take heed.

Elizabeth09:25 January 13, 2019
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Please know that you are not alone with your SUA. Mr. Azuma has some very good suggestions for a car that makes its own decisions. Please continue to pass these thoughts along. Automation of so many things is definitely in every human’s future. These are really very good ideas, and I believe all new drivers should now have this kind of information passed along to them. There are so many drivers with more automated cars who should have this information also! So here’s my story and the truth—– I was rolling very slowly forward in a parking lot. I had decided that I was going to back up and move on to position the car for leaving the lot. Unfortunately, when my event happened with my 2016 Mercedes SUV GL 350, the car took off on its own within seconds and ran me into a curb at a high speed. I am talking probably 10 to 15 seconds. I should’ve just shut off the car but I was in shock. All I thought was that my car is driving me now at very high speed heading right for curb. My foot never hit the brakes or accelerator ever because I was in shock. However, I tried to shift the car with the controls being on the column.This would’ve been so much easier if shifting had been by the console like my BMW especially for this situation. I thought I had made some kind of mistake, but the car definitely did this on its own. Earlier, the car actually had shifted down into D5 a few times on its own and that should’ve alerted me to the computer problem. I had to pull the car over to the side of the road, and turn it on and off. I was able to put the car back into gear. But then once again, I thought I was doing something wrong. The reality is…… the more that car is automated, the more likely a computer might make a poor decision. Of course, I got charged with driver error. There was no hope for a lawsuit against Mercedes either. I wanted to destroy the car, but it wasn’t the best choice financially. To all of you who have experienced this, I send my support and totally understand what you feel.

cor20:53 November 02, 2018
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Suing the manufacturer must be done in SUA.cases filed against manufacturer and success rate? can you give us statistics of Subaru forrester 2016 to 2018 SUA. mine had SUA.thank you.

Steve09:05 February 01, 2019
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Our 2017 Forester has SUA and an incident happened that nearly killed my mother? What can be done?

Ben08:37 October 04, 2018
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driver error does not cause unintended acceleration. It is a auto malfuncsion in the elecktonicks (computer error). It is a time bomb to go off at any time with instant damage. Manufacturers will always claim driver error, what a sad note. Car manufactures should be sued every time it happens until such time they fix the problem. It has happened to me twice with complete denial from the manufacturer.

Howard Wheatley00:42 August 31, 2018
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Er, no… The most common cause is driver error – usually when driving an unfamiliar car. Take your feet off the pedals and check that you are actually depressing the brake pedal and not the accelerator. Brakes will stop a car under full acceleration almost as quickly as when under no acceleration.

Joe lunchbox07:34 December 28, 2018
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Do you work for Ford motor company. 🤓

bloof20:48 December 01, 2018
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Nonsense – I stopped at a junction, with gear in forward and foot firmly on brake. Decided to pull back a yard, so checked mirrors, put gear into reverse, and eased foot slightly off brake. Car shot back like a bullet. Lucky nothing behind. Foot never near accelerator.
Do not trust car now, and want to change – are there any models not subject to this ?

Caren05:06 September 16, 2018
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That wasn’t the case with my 2017 Subaru. Three times it has suddenly started accelerating, and it was quite difficult to stop. Thankfully, I was going very slowly, under 30, when it happened. I am now terrified to drive it. Subaru doesn’t want to know anything. They said if it’s driving normally after that, there’s nothing they can do. (I turned it off, and half an hour later drove it home, which is less than a mile from where it has happened.) I don’t want to drive it to the dealership as I would have to go on high speed highways to get there.

Lisa13:51 August 15, 2018
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One victim of sudden acceleration stated she could not put the car in neutral and could not turn it off. In her case your advice would not be helpful.

Andrew Buckeridge12:50 May 04, 2018
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As the software is defective all bets on any safety features are off. For example, the engine may no longer stop so just get away and let it burn.

bloof21:59 December 01, 2018
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Sorry, the speed you are now going means that the car is out of your control. You have to stop asap. You can’t ” just let it burn “

Gerry00:07 April 24, 2018
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Can an unintended acceleration be caused from a signal sent from another car passing you on the right and turning while you are sitting at a traffic light?