NHTSA Complaint #11685047 — 2019 HYUNDAI ELANTRA

The Knock Sensor Detection System (KSDS) software malfunctioned by failing to detect abnormal vibrations or knocking sounds. As a result, there was significant internal engine damage that caused the vehicle to seize unexpectedly in the middle of traffic on 4/10/25. The car started and abnormal noises were noted from the engine though not significant. week later, car stalled several times on interstate. Prior to the failure, the vehicle exhibited a progressive knocking noise in the engine. After seizing, the vehicle would struggle to start, idle briefly, then stall. It also randomly shut off while driving, creating a serious safety risk. The vehicle was taken to Precision Tune Auto Care, where technicians confirmed problems with the crankshaft, excessive oil consumption/leakage, and metal shavings in the oil, which they attributed to rod bearing and crankshaft wear consistent with Hyundai Campaign 203 (improperly heat-treated piston rings). Despite the KSDS being installed during the initial recall remedy, the system did not activate prior to engine failure. Additionally, no engine or oil warning lamps were illuminated. An oil change was performed at the time, but the vehicle had already burned through excessive amounts of oil since the prior change. Precision Tune Auto Care advised me to take the vehicle to Allen Turner Hyundai. At the dealership, staff confirmed issues with the engine but refused to acknowledge Recall Campaign 203, even when presented with documentation. They also failed to address the malfunctioning KSDS system or the lack of functioning engine/oil warning lamps. They were asked to perform inspection relating to piston ring and rod bearing, though refused. This situation raises major safety concerns, as my engine seized in the middle of traffic without warning. Other owners with a malfunctioning KSDS system could face the same risks, leading to sudden engine failure, potential engine fires, or serious traffic accidents.