For a third time, GM is under investigation for headlight defects after owners of previously unrecalled vehicles claim similar, sudden failures while driving.
To be clear, this isn’t a recall, yet, but the National Highway Traffic Safety Administration is currently evaluating whether a 2015 recall by General Motors involving half-a-million pre-bankruptcy vehicles susceptible to headlight failure should be expanded by a further 312,000 cars and trucks.
Excessive heat under the hood was literally cooking the headlamp driver module which would then predictably cause the low-beams and daytime running lights to stop working while driving.
Should the NHTSA order a callback it would be the second expansion of a 2014 recall already affecting 497,000 vehicles, including the 2005-2009 Buick LaCrosse, the 2006-2007 Buick Rainier, Chevrolet Trailblazer and GMC Envoy, the 2006-2008 Saab 9-7X and Isuzu Ascender and the 2007 Pontiac Grand Prix.
Repairs on affected vehicles began in May 2016, but since then the NHTSA has received a further 128 complaints from owners claiming nearly identical issues on vehicles not included in the original callback.
For example, one owner of a 2004 Trailblazer crashed into a creek after the alleged loss of exterior lighting. Another complaint filed in November of 2016 alleges a 2008 Pontiac G6 lost both its low and high-beams after suffering from the issue intermittently for several months.
The federal agency is currently combing through the data to plot the best course of action, but based on the empirical evidence another recall seems a matter of when, not if.
A version of this story originally appeared on GM Inside News