On Friday, Toyota said its announcement covered about 450,000 Sienna minivans produced between 2004 and 2011, including 370,000 in the U.S. and 80,000 in Canada.
The offer is 15% higher than Pfizer's last bid.
Last bid was made May 2.
Pfizer said it would not attempt a hostile takeover.
Last year, China's auto sales surged to 21.98 million vehicles, according to an industry group, but sales of "new energy" vehicles -- which includes fully electric cars and hybrids -- were tiny at around 25,000 over the past two years.
Japanese reports said bonuses typically make up between 35% and 50% of an executive's remuneration.