my warning sound comes on when braking on a left hand turn. has anyone experienced this with there car and how can i fix this

There is an hydrolic sensor / regulator device near the rear axle which controls the amount of brake applied to the rear. This sensor will leak brake fluid. The replacement part from KIA is $300 or so. A very effective fix is to ensure that your brake fluid is topped up. (Owner of 2004 Sedona EX). Look for a box about 2 x 3 inches, white cover.