TSB: MDPS FLEXIBLE COUPLING REPLACEMENT CUSTOMER SATISFACTION PROGRAM (CS1604) - This bulletin provides information regarding the replacement of the flexible coupling in the Motor Driven Power Steering (MDPS) on some 2011-2014 MY Optima (QF/TF/TFH) vehicles, produced from August 12, 2010 to December 18, 2013. The MDPS unit may experience noise when turning the steering wheel left or right, especially while the vehicle is stopped. Kia?s analysis has identified that this condition occurs mainly in extremely high humidity states adjacent to warm ocean waters due to the wear of the flexible coupling in the MDPS, after extended usage over years. The extremely high humidity states adjacent to warm ocean waters include: Alabama, Florida, Georgia, Hawaii, Louisiana, Mississippi, North Carolina, South Carolina, and Texas. For vehicles sold or currently registered in extremely high humidity states adjacent to warm ocean waters, replace the flexible coupling with a new one if it has not been previously replaced under warranty. Before conducting the procedure, verify that the vehicle is included in the list of the affected VINs. For vehicles sold or registered in all other states, Kia is extending the warranty on the flexible coupling in the MDPS from 5 years/60,000 miles to 10 years/unlimited mileage, starting from the date of first service in order to ensure customer satisfaction. If the MDPS unit experiences noise when turning the steering wheel left or right, replace the affected flexible coupling with a new one.