DETROIT -- U.S. regulators have opened an investigation into General Motors' Hummer H2 after three consumers said a wheel came off the large SUV after a steering part cracked.
The National Highway Traffic Safety Administration said it began a "preliminary evaluation" -- a step that often precedes a recall -- into the 2003 and 2004 model year Hummer H2, which has scored poorly in quality studies conducted by J.D. Power and Associates.
Four consumers complained that the steering knuckle fractured at the lower ball joint attachment, causing them to lose control of the H2, including three who said a wheel separated from the SUV, NHTSA said.
One consumer crashed into a parked vehicle, and a second veered into oncoming traffic before running into a ditch on the opposite side of the road, NHTSA said.
All four consumers said the H2 was not driven off-road or under any abusive conditions.
"We're aware of the investigation and we're cooperating," said GM spokesman Alan Adler.
Despite the poor quality score for the H2, GM has touted its improvement overall in J.D. Power quality studies, including in a full-page ad in the New York Times on Monday.