Hyundai Elantra: Operation Principle - DC/DC Converter. Description and 
Operation - ISG (Idle Stop & Go) System - Fuel System - Hyundai Elantra MD 2010-2015 Service manualHyundai Elantra: Operation Principle

In the ISG mode, if the power of an audio system turns OFF by drawdown while Auto Starting or Idle Starting function operates, replace the DC/DC converter.