Toyota Launches its Vehicle Throttle Suppression System to Prevent Unintended Acceleration

author: Eric Walz   

Although self-driving vehicle technologies are being developed at a rapid pace, it will likely be some time before self driving cars appear on public roads. A lack of regulatory framework around the technology as well as the public acceptance over the safety of self-driving cars are leading automakers to focus instead on developing advanced driver assist systems (ADAS) for when a human is behind the wheel.

Toyota Motor Corp has been a industry leader in developing advanced automotive safety systems and its latest technology will reduce the chance of an accident and vehicle damage if a driver misapplies the accelerator pedal. 

The feature is called "Acceleration Suppression System" and it's being introduced on the Toyota Prius and Prius PHV models in Japan starting July 1 and will gradually be rolled out to other models. The optional feature costs US$358.00 plus installation.

Toyota initially launched this system as part of its "Plus Support" for new cars and added the function in the "Pedal Misapplication Acceleration Control System II" retrofit device for use with existing Toyota models in Japan.

The new feature is an expansion of technology first introduced in 2012 on the Toyota Camry. For the 2012 Camry, Toyota introduced its "Intelligent Clearance Sonar" (ICS). In 2018, Toyota launched a retrofit "Pedal Misapplication Acceleration Control System" for existing models equipped with ICS.

Toyota's ICS was designed to aid when navigating tight parking spaces. The system includes 8 ultrasonic sensors located on the front and rear of the vehicles, as well as on the front and rear corners of the Toyota Camry sedan. It detects objects around the vehicle and provides an audible alarm if a driver gets too close to an object.

The ICS system is designed to automatically apply the brakes if a driver continues to move closer. The ICS system is now standard on the Camry XLE and Camry XSE trim levels.

Examples of Prius and Prius PHV with pedal misapplication prevention functions, including Plus Support.

By combining its existing ICS and retrofit device functions with the Acceleration Suppression function, Toyota believes it can reduce the number of serious accidents caused by pedal misapplication in parking lots and other urban areas. 

The "Plus Support" system in the Prius starts automatically when the vehicle doors are unlocked using a Plus Support enabled Smart Key, which is a dealer-installed option in Japan starting around US$123.00. However with the new system, even if obstacles are absent from the vehicle's surroundings, it's able to detect accelerator pedal misapplication from the driver and suppresses acceleration.

The system only works with a Plus Support enabled Smartkey. If the vehicle's doors are unlocked using a conventional key, the Plus Support feature will not activate, and the vehicle can be driven normally.

These existing systems help prevent accidents caused by accelerator pedal misapplication when sensors detect obstacles such as a wall or glass near around the vehicle.

For example, if a driver was attempting to park in a tight space near a wall of a building the system would detect if a driver inadvertently applied the accelerator too much to help prevent a collision by suppressing the driver's input to the accelerator.

According to data confirmed by Toyota, ICS helps prevent roughly 70 percent of all potential accidents that could occur due to accelerator pedal misapplication. However, the automaker believes that new technologies such as its accelerator suppression system are needed to reduce the remaining number of accidents, including accidents in situations where obstacles are not detected near the vehicle.

In designing its new system, Toyota analyzed actual accidents where the cause was determined to be accelerator pedal misapplication, particularly analyzing situations where the accelerator pedal was unintentionally pressed too fully. 

These incidents were then compared with data collected from Toyota's connected vehicles. By eliminating instances where it was determined that drivers were genuinely required to rapidly accelerate intentionally, such as when turning right or accelerating from a stop, Toyota was able to identify and log instances of accelerator pedal misapplication for further evaluation. 

This led to a function setting to reduce the number of accidents caused by accelerator pedal misapplication by controlling acceleration even in the absence of obstacles.

To prevent false applications of accelerator suppression, the system automatically shuts off whenever the turn signals are on, accelerating up a steep hill or just after applying the brakes.

Toyota was previously under investigation for sudden acceleration incidents in its vehicles, although its was unrelated to pedal misapplication.

In 2002, the National Highway Traffic Safety Administration (NHTSA) opened an investigation after reports of sudden, uncontrolled acceleration on some Toyota Lexus models which led to fatalities. The investigation eventually expanded to 2005 Toyota models.

In Jan 2010, Toyota announced a recall to repair sticking accelerator pedals in 2.3 million vehicles. The recall was eventually expanded to 1 million more vehicles, so Toyota is fully aware of the serious problems caused by unintended acceleration. 

The automaker said it's also willing to share the new technology with Japan's other automakers. Toyota said its is open to sharing the operational logic of the Acceleration Suppression function.

This latest technology is part of Toyota's ongoing commitment to safety. The automaker is taking a three pillar approach to safety, including improving upon existing systems, initiatives to help educate drivers about new safety technology, and other initiatives that seek to improve road safety for all.

Eric Walz

Originally hailing from New Jersey, Eric is a automotive & technology reporter covering the high-tech industry here in Silicon Valley. He has over 15 years of automotive experience and a bachelors degree in computer science. These skills, combined with technical writing and news reporting, allows him to fully understand and identify new and innovative technologies in the auto industry and beyond. He has worked at Uber on self-driving cars and as a technical writer, helping people to understand and work with technology.