Nissan announced Tuesday that it's including a safety feature designed to help prevent the tragedy of children being left in hot cars on more of its 2019 models.

The Rear Door Alert appeared first in the 2018 Pathfinder SUV and will expand to all four-door Nissan vehicles by 2022, including the 2019 Rogue and 2019 Altima.

More than 700 children have died from heatstroke in cars since 1998 (an average of 37 deaths per year), according to Jan Null, a certified consulting meteorologist and lecturer at San Jose State University. Heat stroke remains the leading cause of non-crash-related vehicle deaths for children younger than 14 years old, according to the National Highway Traffic Safety Administration (NHTSA).

To address these risks, child car seat manufacturers and automakers have rolled out heatstroke-prevention solutions integrated into the seats and in vehicles over the past couple of years. The goal is to remind parents or caregivers about children in the rear seats so that adults don't leave kids behind. 

More on the Dangers of Hot Cars

Nissan Rear Door Alert is designed to use “door sequence logic,” messages on the driver instrument panel, and multiple horn honks as a way to remind drivers to check the rear seats after they park. General Motors' Rear Seat Reminder also provides visual and audible warnings in the display but doesn’t use horn honks. 

How Rear Door Alert Works

2018 Nissan Pathfinder with rear seat minder

The Pathfinder owner’s manual says that the Rear Door Alert is activated when any rear door is opened and closed within about 10 minutes of the vehicle being started. Once the vehicle has been started, a “Rear Door Alert is activated” message is displayed; drivers can either “Dismiss Message” or “Disable Alert.”

When the driver shifts from Drive into Park, the message reappears with the option to “Dismiss” or “Disable.” After the driver turns off the car and opens the driver’s door, a “Check Back Seat For All Articles” message is displayed (shown above). To deactivate the alert, one of the rear doors must be opened in a short time (Nissan doesn’t specify how short a time) after the driver exits the vehicle. Otherwise, the horn will honk several times to alert the driver.

The Pathfinder’s owner’s manual describes two scenarios where the alert will sound after the driver has exited the SUV: If the doors are locked before one of the rear doors has been opened, or if the rear hatch is opened and closed before a rear door has been opened.

The factory setting for Nissan Rear Door Alert is off, so car owners must enable this safety feature. “To mitigate possible customer annoyance, Nissan decided to set this feature as default off, with the expectation that customers who specifically want the reminder will be able to activate it easily,” says Nissan spokesman Steve Yaeger.

CR evaluated the system at the CR Auto Test Center to better understand how it works. Here’s what we found. 

CR's Evaluation of Nissan Rear Door Alert

2018 Nissan Pathfinder with rear seat minder

We started by ensuring that the Rear Door Alert system was enabled. That was a task in itself, as it required us to use buttons on the steering wheel and navigate the settings in the instrument cluster. Drivers can opt to set the system to Off, Alert & Horn, or Alert Only. We selected the Alert & Horn option (shown above).

We evaluated two key elements of the system: whether the system engaged as expected after starting the engine within 10 minutes of opening and closing a rear door, and whether the visual and horn alerts appropriately warn drivers.

To determine the timing issue, we conducted multiple trials. These showed that the Rear Door Alert activation depended on the time between opening and closing the rear door and then the driver’s door, and not by when the engine was started.

In our trials, when we entered the driver’s door at any point after 9 minutes and 44 seconds past the point when we opened and closed the rear doors, the system did not activate. This makes sense; it's natural for parents to quickly enter the car after putting their kids in a back seat, even if they don’t turn the engine on immediately.

When the visual alert launches, the alert message appears in the driver instrument cluster when the SUV is in Park and the engine has been turned off, as expected. Open any door, though, and that warning message gets obscured by a “Door Open” message.

The audible alert—multiple horn honks—also sounded as expected if we did not open a rear door within 10 to 12 seconds after stopping and exiting through the driver’s door. The “Check Back Seat . . . ” message displayed for about a minute after the audible alert sounded, giving the driver time to respond. We also tried locking the doors with the key fob after exiting the vehicle, as well as opening and closing the rear hatch, and both times the audible alert sounded as expected.

We also simulated two real-world scenarios:
• A driver stopping while conducting an errand, such as going through a drive-through or ATM; and
• A driver dropping off a child at school.

If stopping for an errand, drivers typically don’t shut off the car, but they do place the car in Park. In our errand testing, the alert sounded after we reached our final destination and exited the SUV.

However, in the drop-off scenario, a rear door opened and closed at the stop (the car was placed in Park with the engine running) and a child exited the vehicle. The driver continued on. But when the driver finally parked and exited the SUV, there was no visual or audible alerts given, which was not the expected outcome. 

Bottom Line

CR applauds Nissan for recognizing the importance of an integrated vehicular heat stroke prevention system and making Rear Door Alert standard equipment on the Pathfinder. We firmly believe that no parent or caretaker thinks such a tragedy could happen to them and therefore, they’re unlikely to buy an aftermarket product to deal with that situation.

Still, with that understanding in mind, we would prefer for the Rear Door Alert default to on for owners, requiring them to opt out if this feature does not fit their lifestyle rather than having to opt in.

“The only thing worse than not having an alert like this is having one and thinking it is enabled when it is not,” says David Friedman, director of cars and product policy and analysis for Consumers Union, the policy and mobilization division of Consumer Reports. “These alerts should be enabled by default and they should not be easy to routinely disable.”

In addition, this feature works only if the rear doors are opened and closed before the driver enters the SUV and turns on the car. If the driver gets in the car and starts it to warm it up before opening the rear doors, then the system is not engaged. And, as we noted above, opening a rear door to drop off a passenger would not engage the system, even though a toddler or infant might still be in a child seat back there.

Lastly, the activation and visual alert messages are accompanied by a hard-to-notice single chime, which doesn’t really grab the driver’s attention; we think the warning sound should be more distinctive and repetitive.

We hope that Nissan will fine-tune Rear Door Alert as the safety feature appears in more vehicles and that the alert will be a factory-defaulted-on system. We implore other automakers to follow Nissan and GM's lead. 

2018 Nissan Pathfinder with rear seat minder

Keeping Kids Safe From Hot Cars

Just how hot can the inside of a car get? On the "Consumer 101" TV show, Consumer Reports expert Emily Thomas, Ph.D., shows host Jack Rico how rapidly interior temperatures can rise—and what you can do to protect your kids.