NHTSA Preliminary Evaluation PE13033

On October 28, 2013, Hyundai Motor Company (Hyundai) submitted a Defect Information Report (DIR) to NHTSA describing a safety defect in the braking system of approximately 43,500 model year (MY) 2009 through 2012 Hyundai Genesis sedans (NHTSA Recall No. 13V-489).The Hyundai report indicates that the recalled vehicles may contain brake fluid that does not sufficiently inhibit corrosion on the zinc plating of control valve armatures in the Hydraulic Electronic Control Unit (HECU) module. The DIR indicated that, over time, the build-up of corrosion products may affect operation of HECU control valves, resulting in a low/soft brake pedal with reduced brake effectiveness, which may increase the risk of a crash.In October 2011, the HECU supplier notified Hyundai that the brake fluid used in production plants was causing corrosion of valve armatures in the control module.The supplier changed the coating of the valve armatures in late March 2012 to correct the problem in production vehicles.Hyundai's recall includes Genesis vehicles produced prior to the implementation of the HECU change.In March 2013, Hyundai initiated a Service Campaign (TL6) to replace brake fluid in the subject vehicles with brake fluid with better corrosion resistance properties.According to Hyundai's DIR letter, after PE13-033 was opened, the company noted that some of the vehicles serviced in the TL6 campaign subsequently required HECU replacement.This was an indication that internal corrosion had progressed enough to affect valve operation and brake performance, prompting Hyundai to conduct a safety recall.Hyundai's repair procedures for 13V-489 require brake system flushing and replacement in all recalled vehicles with a new fluid containing the necessary corrosion inhibitor.In addition, for vehicles produced prior to June 1, 2010, dealers will perform an inspection procedure to verify that the HECU is functioning properly and replace units that do not meet the test requirements.Hyundai indicated t