WASHINGTON (CNN) -
Federal authorities have opened an investigation of more than 1.2 million General Motors Corp. pickup trucks and sport utility vehicles in 21 "salt belt" states amid questions about the vehicles' antilock brakes.
The National Highway Traffic Safety Administration said that it initiated the investigation into an estimated 1,276,000 1999-2002 General Motors (Research) C/K series trucks in Salt Belt states on April 28.
The agency said a buildup of corrosion on the antilock brake system may cause it to activate improperly at low speeds, increasing stopping distances.
Last November, the automaker recalled approximately 150,000 of its vehicles from eastern Canada to fix the same problem. The company said then that the failure rate was 0.32 incident per thousand of the recalled vehicles.
The rate in the United States was a tenth that: 0.03 incidents per thousand vehicles, NHTSA said. That's about one incident for every 30,000 vehicles.
The agency's office of defects investigation said it has received 123 complaints involving 1999-2002 C/K trucks in U.S. salt-belt states.
In 22 cases, a crash is alleged to have occurred, including one that involved six vehicles and four injuries, the agency said.
The vehicles covered are the 1999-2001 GMC Sierra, 1999-2001 Chevrolet Suburban, 1999-2001 Chevrolet Silverado, 2001 Cadillac Escalade, 1999-2000 GMC Tahoe and the 1999 GMC Yukon Denali.
Salt-belt states are Connecticut, Delaware, Illinois, Indiana, Iowa, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, Virginia, West Virginia and Wisconsin. The District of Columbia is also included.
A GM spokesman did not immediately return a call.
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