U.S. safety regulators have upgraded an investigation more than 382,000 Saturn Ion cars for possible steering problems.
The National Highway Traffic Safety Administration said it opened the engineering analysis after it and Saturn, a brand General Motors discontinued in 2009, received more than 4,000 complaints about sudden loss of electronic power steering assist in cars from model years 2004 through 2007.
Sixteen of the complaints said the power steering warning lamp had illuminated before or during the loss of power steering assist and the increased effort required to steer contributed to a crash, according to documents filed by NHTSA. Two of the crash claims indicated the driver was injured.
NHTSA also said GM had received 17,385 warranty claims related to the issue.
A GM spokesman said the automaker was cooperating with NHTSA.
Last year, GM recalled 1.05 million Chevy Cobalt and Pontiac G5 vehicles to correct a defect in the electronic power steering assist motor, according to NHTSA. The defect was described as a buildup of brush debris mixed with oily material that caused the motor to stop functioning; "the same problem identified in the current subject vehicles," NHTSA said.
Previously NHTSA investigated the sudden loss of power steering assist in model year 2005 through 2010 Chevrolet Cobalt vehicles.
In May 2011, GM provided safety regulators with complaint, warranty and power-steering system information for the Ion, as well as the Pontiac G6 and Chevy Malibu, according to NHTSA. In that response, GM indicated the power-steering system used in those vehicles was the same as that used in model year 2005 to 2010 Cobalts and Pontiac G5s.
NHTSA said it has duplicated the power-steering system failure in both a Cobalt and an Ion previously tested.