2019 Hyundai Santa Fe Rear Occupant Alert.
Hyundai rolled out a new technology in the redesigned 2019 Santa Fe SUV that could help prevent parents from leaving a child in the back seat of a hot car. Hyundai’s system, called Rear Occupant Alert, goes a step beyond competitors’ systems because in addition to reminding drivers that the rear door was opened prior to the trip, it continues to monitor the rear seat for motion after the vehicle is parked and all doors are locked. “Hyundai’s two-stage warning system—which uses door logic as well as an ultrasonic motion sensor located in the ceiling behind the rear seat—is a step above what other automakers are offering, based on our evaluation,” says Emily Thomas, Ph.D., Consumer Reports’ automotive safety engineer. CR likes that Hyundai’s version defaults to “on,” rather than relying on parents to activate it. This is important because many people believe they would never forget their child and so might not turn on the system. CR hopes that Hyundai makes the system available on all Santa Fe trim lines, not just the SEL Plus and above.
Hyundai’s initial door logic reminder warning appears in the instrument cluster and worked reliably in our testing. (This is similar to the rear-seat reminder systems we’ve evaluated from General Motors and Nissan.) If a rear door is opened and closed and the car is turned on, the driver will get a visual and audible rear-seat reminder alert when the car is turned off and the driver begins to exit the vehicle. The second stage of Hyundai’s system is designed to provide an extra layer of protection. If the vehicle is locked and the ultrasonic sensor detects movement in the rear seat, the horn will honk on and off for approximately 25 seconds. If the alert is not disabled by unlocking the vehicle and opening the rear door, and the sensor detects movement again, the horn will sound for another 25 seconds. This sequence will be performed up to eight times. After the eighth time, the alert will not sound again, even if it has not been disabled. The system also can be configured to send a text message or an email to the owner via Hyundai’s Blue Link telematics when the second alert is triggered. (Subscription is free for the first three years.) “The ultrasonic sensor wasn’t always reliable in our testing, though,” says CR’s Thomas. “The movements need to be large and constant to set it off, possibly larger than most infants would make. It also might not detect a pet on the floor unless the animal got up and started moving around the rear cabin.” Hyundai officials told CR that the sensor’s limitations prevent it from detecting slight movements, such as the rise and fall of the chest when breathing.
2019 Hyundai Santa Fe Rear Occupant Alert warning.
Santa Fe rear-seat warning.
We were also concerned that the system requires the doors to be locked to trip the motion detector. We could envision a scenario when a driver parks the car at home but doesn’t lock the vehicle and forgets that a child is inside. Hyundai’s engineers told us they set it up this way to avoid triggering an embarrassing horn alarm in situations such as filling up at a gas station. Hyundai’s system can help parents avoid tragedies, and it goes beyond existing factory-installed warning systems, but it’s not foolproof.
“I wouldn’t rely on the movement of a young infant in a hot car to be the event that trips a sensor, especially for newborns or babies that are already asleep,” says Elizabeth Murray, D.O., spokeswoman for the American Academy of Pediatrics. While Murray says she can’t predict exactly how a child will react in a hot car, she told us it could be similar to what has been seen in children with hyperthermia. “There can be some mild irritation, they may cry, and their breathing will likely become heavy, but I would not assume large amounts of movement would happen.” Rear-seat reminder systems are becoming more important than ever. It looks like 2018 could become the deadliest year for child vehicular heatstroke deaths in U.S. history. There have already been 29 confirmed pediatric heatstroke deaths in cars this year thus far, according to NoHeatStroke.org. On average, 37 children die in hot cars in the U.S. each year. “We need more solutions that are integrated into the child seat or vehicle that are foolproof,” says Aditya Belwadi, Ph.D., of the Center for Injury Research and Prevention at the Children’s Hospital of Philadelphia. “We released a study funded by NHTSA in 2012 which evaluated commercially available aftermarket products designed to prevent children from being left behind in parked vehicles, and we found a series of limitations with the devices tested which were designed to detect the presence of a child in a car seat.”
2019 Hyundai Santa Fe rear occupant sensors.
Sensors in the Santa Fe's headliner.
CR’s take: We applaud Hyundai for its heatstroke prevention advances. Based on numerous CR tests, it offers a welcome protection against hot-car tragedies. But as with any of these systems, it’s important for parents and caregivers not to become overly reliant on technologies. Parents and pet owners need to understand how quickly a vehicle can heat up to dangerous levels, believe that it can happen to them, and implement multiple strategies to avoid child and pet heatstroke tragedies.

What You Can Do

The first step to preventing these hot-car tragedies is for parents and caregivers to understand that human memory is faulty and that these memory failures can happen to anyone. The key to avoiding such incidents is to use strategies aimed at overcoming memory lapses. Some strategies from the CR car seat team include:
•  Create safeguards. One idea is to create a mutual child safety agreement, such as Ray Ray’s Pledge, when parents promise to notify child-care providers if their child is going to be late or absent. In return, the child-care providers pledge to notify parents if children do not arrive at their usual drop-off time.
•  Set reminders on your phone. This can remind you to check with your spouse or partner to make sure he or she has dropped the child off.
•  Use visual reminders. Place the child’s diaper bag, jacket, or hat in the front passenger seat.
•  Force yourself to go to the backseat. Keep your backpack, lunch box, briefcase, or something else you may need there every day.
•  Never leave a child unattended. Vehicles can quickly heat up to potentially fatal levels even on mild-temperature days. So leaving a child in a vehicle is a no-no for any length of time, regardless of the outside temperature.

“When my now-14-year-old son was an infant, this almost happened to us,” says Jennifer Stockburger, director of operations at CR’s Auto Test Center. “My husband was responsible for dropping our son at day care one day, which was not his normal routine. He drove far past the day care, and only when our son made some noise did he realize his mistake. Even if you can’t imagine making such an error, I encourage parents to use the tips to safeguard their children.” Concerned parents can contact federal lawmakers at Congress.gov to urge them to support the bill known as the HOT CARS Act. The bill would require cars to come equipped with technology that alerts drivers if a child is left in the backseat after the ignition is turned off. It’s endorsed by Consumers Union, the advocacy division of Consumer Reports.