This bulletin announces availability of new audio system amplifiers to address the following operating concerns with the Harman Kardon Gen 3 infotainment system: Symptom 1: No audio output is heard but, the volume level displayed changes when turning the knob Symptom 2: Audio volume increases to maximum intermittently without turning the knob Symptom 3: A buzzing, screeching or crackling-type sound is heard coming through the speakers.