Brake Fluid Level Warning Switch

Remove the connector (A) from the switch located at the brake fluid reservoir.
Verify that continuity exists between switch terminals 1 and 2 while pressing the switch (float) down with a rod.

Fig 1: Locating Brake Fluid Level Warning Switch Connector
Courtesy of HYUNDAI MOTOR AMERICA
If continuity is not as specified, replace the brake fluid level warning switch.