— General Motors headlight failures caused recalls, extended warranties and a federal investigation that was opened in 2017.
But after nearly four years, the National Highway Traffic Safety Administration (NHTSA) has closed the investigation without taking any additional action.
About 318,000 of these vehicles are included in the investigation.
- 2005-2009 Buick LaCrosse
- 2006-2007 Chevy TrailBlazer
- 2006 Chevy TrailBlazer EXT
- 2006-2007 GMC Envoy
- 2006 GMC Envoy XL
- 2006-2007 Buick Rainier
- 2006-2008 Saab 9-7X
- 2006-2008 Isuzu Ascender
- 2007 Pontiac Grand Prix
The vehicles suffered low-beam headlight failures when the headlight driver modules failed, something that could happen to both headlights while driving.
GM says the modules can overheat inside the electrical centers under the hoods during normal driving conditions, causing module failures, headlight failures and failures of both daytime running lights.
Drivers have no warning of problems until the lights go out. In addition, it's possible the lights may come back on, or the problem may be permanent until repairs are performed.
The automaker recalled hundreds of thousands of vehicles in 2014 and 2015, then GM issued an extended warranty program in 2017 for vehicles that had both headlights fail at the same time due to module failures.
According to the headlight warranty extension, GM dealers will repair the headlight modules for free if both headlights failed within 12 years of the vehicle's in-service date or 150,000 miles, whichever occurs first.
NHTSA closed the investigation based on GM's actions related to headlight failures, but federal safety regulators say closing the investigation "does not constitute a finding by NHTSA that a safety-related defect does not exist."