Avoiding Unintended Acceleration & Floor Mat Recalls

How to Stop Unintended Acceleration
VIDEO: How to Stop Your Car in the Event of a Stuck Throttle Pedal
What is Unintended Acceleration?

How to Stop Unintended Acceleration

How do you stop a car that suddenly accelerates and seems to have a mind of its own? This is probably the most terrifying situation a motorist can find him- or herself in. Knowing what to do before it happens can help drivers react quickly to avoid an accident.

Floor mats have been identified as potential problems. When floor mats are improperly installed in nearly any vehicle, or when heavy winter floor mats are stacked on top of the carpeted mats, they can prevent the accelerator pedal from returning to idle. Edmunds' Inside Line uncovered potentially dangerous floor mats in several vehicle models during a floor mat walkaround evaluation of our own vehicles.

Sticking accelerator pedals have also been identified as a potential problem in some Toyota vehicles, and the company has issued a voluntary recall to address the issue.

"If a driver ever feels as if the accelerator is stuck, he or she should try pull the pedal up with a toe, put the car in neutral, pull the car over to a safe place, shut the car down and have it towed to the dealership," advises Edmunds.com's Director of Vehicle Testing Dan Edmunds.

As industry experts continue to probe for any other possible cause of the problem, the recalls of various affected models continue. To help concerned owners we've put together a guide to all the latest Toyota accelerator pedal recall information as well as an essential report about how to stop a runaway vehicle.

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What is Unintended Acceleration?

"Unintended acceleration" is a term we hear a lot lately. But what is it, exactly? What causes it?

Unintended acceleration describes any situation where your car accelerates when you do not want it to. There are many factors that can cause this frightening, but very rare, situation.

In some cases, unintended acceleration is the result of the driver accidentally stepping on the gas pedal when he/she means to apply the brakes. In the 1980s, this was found to be the cause of the Audi's much publicized sudden acceleration cases. It turned out that the brake was too close to the gas pedal. Once Audi made changes to the pedal layout it solved the problem.

Unintended acceleration sometimes occurs when the driver is wearing wide shoes, or winter boots, and their footwear catches the edge of the gas pedal and pushes it down, too.

The first of Toyota's recalls involved heavy winter floor mats, which were made of thick rubber, which interfered with the gas pedal. This occurs when the mats become free of their retaining hooks or are stacked on top of the standard carpet mats, locking the gas pedal in the fully open position. Such a scenario happens when a driver presses the accelerator all the way down to pass someone, climb a grade or merge onto the freeway. The driver is finished with the maneuver and releases the gas, only to have the trapped pedal keep the car driving ever-forward.

Toyota's second recent recall involves a gas pedal hinge mechanism that can develop excess friction until it sticks and does not return to idle. Again, this situation occurs after the driver accelerates, only to be surprised when the car fails to respond when it's time to slow down.

Other possible causes include software problems, electromagnetic interference or other unseen electronic faults that may confuse today's modern electronic throttle systems. However, no such cause has yet been duplicated in controlled conditions.

Some reported vehicle problems are less clear instances of unintended acceleration. There have been reports of cruise control systems that don't cancel with a tap of the brake, but the "off" switch still works as intended (or vice versa). Initial hesitation in acceleration response followed by a surge as the engine and/or transmission finally responds is not unintended acceleration in the normal sense of the term. It's unsmooth and it's annoying, but it's not the sort of runaway condition we usually associate with unintended acceleration.

So-called brake override systems exist on some cars to combat unintended acceleration. These systems monitor gas pedal and brake inputs and cut acceleration if both pedals are pressed at the same time. Most systems are set up to delay this action until pressing on the brake is forceful enough to indicate that the driver does indeed have a problem. Such a system offers a way out of a scary unintended acceleration situation, but it's not the ultimate solution because it addresses the symptom, not the root cause. And a brake override has no effect in cases where the driver simply steps on the wrong pedal.

Describing all these scenarios should not be interpreted to mean that unintended acceleration is common. It is a rare condition that most drivers will never experience. But knowing what might be going on can make the situation a little less scary, and it will help you drive your way out of a dangerous situation.

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