Japanese carmakers are considering following Toyota Motor's lead in adopting a brake override system that would potentially address all sources of unintended acceleration, including driver error.

Under fire after recalling more than 8 million vehicles globally for problems of uncontrollable acceleration, Toyota said last month it would add the function to all future vehicles worldwide. The system cuts engine power when the accelerator and brake pedals are applied at the same time.

Nissan Motor, held 44 percent by France's Renault, is the only Japanese carmaker that has a function on nearly all of its cars that prioritizes the brakes when both pedals are depressed. This excludes 660cc minivehicles sold in Japan under the Nissan badge and cars produced by other automakers on an original equipment manufacturing (OEM) basis.

Among Japan's eight carmakers, Mazda Motor said it would add the system to all future models as soon as possible starting this year.

We decided to do this because it's the right thing to do, Mazda spokesman Garett Carr said on Tuesday. He added that Mazda currently has the feature on some diesel cars sold in Europe.

Morgan Stanley auto analyst Noriaki Hirakata wrote in a recent report that the cost of installing a brake override system was about $50 a vehicle, adding that it could come down if more brands adopt it.

Honda Motor, Suzuki Motor, Mitsubishi Motors, Subaru-maker Fuji Heavy Industries and Toyota unit Daihatsu Motor all said they were considering adopting the system. The timing and scope of the roll-out were still under study, they said.

I think (it) could eventually become a standard feature, just like airbags or anti-lock brake systems, said Daihatsu spokesman Haruki Mori.

Unintended acceleration in Toyota and Lexus vehicles -- at the heart of the automaker's recalls -- has been linked with at least five U.S. crash deaths since 2007. The causes of many cases of unintended acceleration are unknown, and are often blamed on driver error.

U.S. Transportation Secretary Ray LaHood has said that safety regulators may require all new cars to have braking systems that tell the engine to return to idle when both accelerator and brake pedals are depressed.

Toyota estimates that about one-fifth of vehicles sold in the United States have brake override systems. That includes vehicles sold by Mercedes-Benz (DAIGn.DE), Volkswagen (VOWG_p.DE) and Chrysler.

(Editing by Chris Gallagher)