Regulators Upgrade Probe of GM Trucks

Federal safety regulators have upgraded a probe of tailgate failures on full-size pickup trucks built by General Motors Corp.

The National Highway Traffic Safety Administration classified its investigation of the trucks as an “engineering analysis” -- a step that can precede a recall.

Such a recall would involve nearly 4.5 million of the pickups, including the 1999-2003 Chevrolet Silverados and GMC Sierras and 2002-03 Chevrolet Avalanche and Cadillac EXT trucks, NHTSA said.

The company reported 96 injuries linked to the tailgate problem.