TSB: SERVICE ACTION: FRONT SEAT HEADREST ELEVATOR MODULE REPLACEMENT (SA177) - THIS BULLETIN PROVIDES THE PROCEDURE TO REPLACE THE HEADREST ELEVATOR MODULE OF SOME K900 (KH) VEHICLES, PRODUCED FROM MARCH 20, 2014 THROUGH SEPTEMBER 19, 2014 AND EQUIPPED WITH MANUALLY ADJUSTABLE HEADRESTS, WHICH MAY EXHIBIT DIFFICULTIES WHEN ADJUSTING THE HEADREST HEIGHT. TO PREVENT AND/OR CORRECT THIS CONDITION, REPLACE THE HEADREST ELEVATOR MODULE WITH A NEW ONE BY FOLLOWING THE SERVICE PROCEDURE OUTLINED BELOW. KIA IS REQUESTING THE COMPLETION OF THIS SERVICE ACTION ON ALL AFFECTED VEHICLES, INCLUDING DEALER STOCK, PRIOR TO DELIVERY.