WASHINGTON -- U.S. auto safety regulators have stepped up their investigation into the Pontiac G6, bringing the discontinued sedan a step closer to a recall for brake light problems.
The National Highway Traffic Safety Administration started an investigation Feb. 4 into 2005-08 G6s. In a new filing on its Web site, NHTSA says it has begun an engineering analysis of those G6s "to determine whether the subject vehicles present a safety-related defect trend."
The investigation could affect 551,511 cars.
"We have been and continue to work with the NHTSA on this investigation," a GM spokesman said in an e-mail.
Owners of the G6 have complained that its brake lights will illuminate when the brake pedal is not depressed, and will turn off even when the driver presses the brake. Some drivers also reported problems while shifting out of park -- which requires the brake to be pressed -- and problems with the cruise control.
GM has provided NHTSA more than 1,100 reports about the brake lights in these vehicles, and NHTSA has received 314 complaints. The agency and GM say they have each received one report of a crash.
GM sold more than 150,000 Pontiac G6 sedans in both 2006 and 2007 before sales dropped to about 140,000 in 2008 and 87,000 in 2009.
NHTSA begins an engineering analysis when its preliminary evaluation suggests that a vehicle may have a harmful defect.
Based on the outcome of the engineering analysis, a vehicle may be recalled or the inquiry may be closed without further action.
Reuters contributed to this report.