Defect
On certain vehicles, the automatic headlamps may not turn on soon enough as it becomes dark outside. Canadian regulations require automatic headlamps to turn on when the ambient light level drops below a certain point (1000 lux).
Safety Risk
Headlamps that don't turn on as it becomes dark outside could reduce visibility and increase the risk of a crash.
Remedy
General Motors will notify owners by mail and advise you to take your vehicle to a dealership to update the body control module (BCM) software.