One Daytime Running Light (DRL) intermittently flickers. One Daytime Running Light (DRL) intermittently lights up with more intensity then dims back to normal. The headlight beams still function normally. The LED DRL control unit's PWM output reacts to an intermittent system voltage change, causing the LED to flicker or change intensity. DTCs will not be logged in the vehicle electrical system control module, J519 (09). The customer complaint can only be sporadically reproduced.