2012 Hyundai Sonata HybridEnlarge Photo
With Hyundai’s recent announcement that brake throttle override, which it calls brake pedal throttle override capability, is now standard on all 2012 Hyundai models effective with May production, consumers may be curious about what this safety technology is all about, as well as what other automakers have it and why.
In essence, brake-throttle override technology lets drivers control a vehicle’s speed and stop it in case of unintended acceleration. With Hyundai’s system, any brake pedal input by the driver has top priority in all driving situations and overrides any throttle inputs.
The 'why' is fairly straightforward. Brake-throttle override, although called by different names, is an additional “failsafe” safety technology. Beyond that, the National Highway Traffic Safety Administration (NHTSA) has issued a Notice of Proposed Rulemaking that is posted on its website (a 98-page PDF document). The proposed brake-throttle override regulations would go into effect September 1 two years from the date of the final rule.
The NHTSA’s proposed brake-throttle override regulation would set minimum requirements for existing as well as future light brake-throttle override systems. Based on the agency’s experience with them, existing systems will meet the proposed standard without modification. In the event that some systems do require changes to meet the proposed standard, the NHTSA believes those changes would be minimal.
Automakers that have it
Although the safety technology is currently making news, some automakers have offered it for years, while others are just now implementing it, either on select models or across their lineup.
2012 BMW 3-Series long-wheelbase modelEnlarge Photo
BMW originated the electronic throttle pedal or “drive-by-wire” system in the 1988 BMW 750iL. By 1994 all BMW products sold in the United States had electronic throttle pedals. Since the very first system in 1988, every BMW Group electronic throttle system (including BMW, MINI and Rolls-Royce) has incorporated a brake override feature. The brake override feature is installed on all transmission versions: automatic, manual, sequential manual gearbox (SMG) and dual-clutch transmission (DCT).
See why our editors give the 2012 BMW 3 Series an overall 8.6 (out of 10) rating in this review.
2003 Dodge Ram 1500 HemiEnlarge Photo
Chrysler implemented brake override with production of the 2003 Ram 1500 with the 5.7-liter HEMI engine. The safety feature has been on all gasoline engines with Electronic Throttle Control (ETC) since that timeframe. The last production vehicle without ETC was the PT Cruiser, which ceased production in 2010.
Here’s how brake override works in all Chrysler, Dodge, Ram and Fiat vehicles built in the U.S.: The vehicles are calibrated such that the brake pedal must have been applied after the accelerator pedal to dial back throttle In addition, the duration of the accelerator-pedal application required to trigger this response is approximately two seconds.
2005 Ford Escape HybridEnlarge Photo
Ford began migrating brake-throttle override, or Brake Over Accelerator (BOA), as the automaker calls it, in 2004 and the first product it appeared on was the 2005 Ford Escape Hybrid. By the end of calendar year 2010, it was implemented on nearly 100 percent of Ford and Lincoln light-duty models (excluding select low volume vehicles, such as certain trucks with a Cummins diesel engine). Owners of these trucks may not want BOA because they are backing up trailers or putting boats in the water, etc.
Brake Over Accelerator is a Ford-designed system. It is on manual and automatic transmission vehicles and operates the same. BOA is also on Ford hybrid and electric vehicles but operates a little bit differently than conventional powertrain vehicles. The system works the same way but the software calibration is a little different.
The BOA system monitors the accelerator pedal and the brake pedal position. If it senses brake pedal application and accelerator position not changing (for example, the accelerator is stuck or trapped), the electronic throttle is driven closed to idle position by the powertrain control module. As the throttle is driven closed, the brake force acts on the vehicle and it slows down—to a complete stop if the driver continues to apply the brakes.
Ford says that the system acts “very quickly.” When the brake is released, the system resumes normal operations, but the throttle is ramped back to the requested pedal position to allow a controllable acceleration. It also works in reverse.
2011 Chevrolet CruzeEnlarge Photo
At General Motors, the safety feature is known as “enhanced smart pedal technology,” and will be implemented globally on all its passenger cars with automatic transmissions and electronic throttle control by the end of 2012.