Check the Power Source Circuit

Disconnect the connector from the ABS (ESC) control module.
Turn the ignition switch ON, measure the voltage between terminal 3(31) of the ABS (ESC) control module harness side connector and body ground.
Specification: approximately B+
Is the voltage within specification?
YES
- Check the ground circuit.
NO
- Check the harness or connector between the fuse (10A) in the engine compartment junction block and the ABS (ESC) control module. Repair if necessary.
  
  Fig 1: Measuring Voltage Between Terminal 3(31) Of ABS (ESC) Control Module Harness Side Connector And Body Ground
  Courtesy of HYUNDAI MOTOR CO.