This feature lets you use the high-beam headlamps to signal the driver in front of you that you want to pass. It works even if your headlamps are off.
Pull the turn signal lever toward you briefly to flash-to-pass.
If the headlamps are off or on low beam, the high-beam headlamps will turn on. They will stay on as long as you hold the lever toward you and the high-beam indicator on the instrument panel cluster will come on.