"To our knowledge, no one is asking for this protection. If these tariffs are imposed, consumers are going to take a big hit," said John Bozella, President of Global Automakers, a trade group representing foreign manufacturers doing business in the U.S. "This course of action will undermine the health and competitiveness of the U.S. auto industry."
According to the department, over the past two decades, passenger vehicle imports have grown from 32 percent of cars sold nationwide to 48 percent, while employment in motor vehicle production has declined.
The investigation "will consider whether the decline of domestic automobile and automotive parts production threatens to weaken the internal economy of the United States," the Commerce Department said.
Mexico, Canada, Japan, Germany an South Korea are among the biggest exporters of cars to the U.S.
But automakers' advocates argue that domestic production remains strong.
"Contrary to the assumption underlying the investigation on import vehicles, the U.S. auto industry is thriving," Bozella said.
"Last year, 13 domestic and international automakers manufactured nearly 12 million vehicles in the U.S. The auto sector remains the leading exporter of manufactured goods in our country," Bergquist said. "During the last 25 years, 15 new manufacturing plants have been launched in the U.S. – resulting in the creation of an additional 50,000 direct and 350,000 indirect auto jobs throughout America – and new plants are on the way."
"We urge the Administration to support policies that remove barriers to free trade and we will continue to work with them and provide input to achieve that goal," she said.
This isn't the administration's first foray into a Section 232 investigation.
In March, Trump used his Section 232 authority to slap tariffs on steel and aluminum — another hotly contested policy move.
ABC News' Meridith McGraw contributed to this report.