It seems like a common convenience in a digital age: a car that can be powered on and off with the push of a button, rather than the mechanical turning of a key. But it is a convenience that can have a deadly effect.
On a summer morning last year, Fred Schaub drove his Toyota RAV4 into the garage attached to his Florida home and went into the house with the wireless key fob, evidently believing the car was shut off. Twenty-nine hours later, he was found dead, overcome with carbon monoxide that flooded his home while he slept.
"After 75 years of driving, my father thought that when he took the key with him when he left the car, the car would be off," said Mr. Schaub's son Doug.
Mr. Schaub is among more than two dozen people killed by carbon monoxide nationwide since 2006 after a keyless-ignition vehicle was inadvertently left running in a garage. Dozens of others have been injured, some left with brain damage.
Keyless ignitions are now standard in over half of the 17 million new vehicles sold annually in the United States, according to the auto information website Edmunds. Rather than a physical key, drivers carry a fob that transmits a radio signal, and as long as the fob is present, a car can be started with the touch of a button. But weaned from the habit of turning and removing a key to shut off the motor, drivers — particularly older ones — can be lulled by newer, quieter engines into mistakenly thinking that it has stopped running.
Seven years ago, the world's leading automotive standards group, the Society of Automotive Engineers, called for features like a series of beeps to alert drivers that cars were still running without the key fob in or near the car, and in some cases to shut the engine off automatically.
The National Highway Traffic Safety Administration proposed a federal regulation based on that idea, a software change that it said could be accomplished for pennies per vehicle. In the face of auto industry opposition, the agency let the plan languish, though it says a rule is still under consideration.
For now, regulators say they are relying on carmakers to incorporate such warning features voluntarily. But a survey of 17 car companies by The New York Times found that while some automakers go beyond the features recommended by the standards group, others fall short.
Safety measures have been a matter of contention among automakers, sometimes even internally. Toyota, for example, has a system of three audible signals outside the car, and one inside, to alert drivers getting out of a vehicle that the motor is still running. But when Toyota engineers determined that more effective warning signals were needed — like flashing lights or a unique tone — the company rejected the recommendation, according to testimony in a wrongful-death suit.
Toyota models, including Lexus, have figured in almost half of the carbon monoxide fatalities and injuries identified by The Times. Toyota says its keyless ignition system "meets or exceeds all relevant federal safety standards."
Some automakers have designed newer models that alert drivers more insistently when the engine is left running — or that shut it off after a certain period. Ford's keyless vehicles now have a feature that automatically turns off the engine after 30 minutes of idling if the key fob is not in the vehicle, the company said recently. (According to a federal lawsuit, Ford began introducing the feature in 2013.)
But many older vehicles have not been retrofitted to reduce the hazard, despite the modest expense of doing so. It cost General Motors $5 per car to install the automatic shutoff in a 2015 recall, according to a G.M. report to the safety agency.
Regulations require automakers to address other hazards associated with keyless vehicles — theft and rollaways — and those measures might also reduce the carbon monoxide danger. But the safety agency has found shortcomings and inconsistencies by automakers in meeting those rules.
As the number of carbon monoxide deaths grows, the hazard is no secret. A Florida fire chief saw so many cases that he took to handing out carbon monoxide detectors. And litigation against the companies is mounting.
"We're going to continue to see deaths and injuries," said Sean Kane, founder of Safety Research and Strategies, an auto safety research group. "And the manufacturers will continue to settle cases."
The exact number of deaths related to carbon monoxide from keyless-ignition vehicles left running is unknown, as no federal agency keeps comprehensive records. Through 2016, the most recent year for which data is available, the safety agency had investigated only four fatal incidents. From news reports, lawsuits, police and fire records and incidents tracked by advocacy groups, The Times has identified 28 deaths and 45 injuries since 2006, but the figures could be higher.
Carbon monoxide is odorless and colorless, depriving the heart, brain and other vital organs of oxygen. Victims are sometimes found with a cherry red rash, a symptom of carbon monoxide molecules attaching to red blood cells. Some who survive live with irreversible brain damage. One couple described a life where they now struggle with severe memory loss and are dependent on hired assistants.
The gas level in Fred Schaub's home was at least 30 times the level that humans can tolerate. His body was found in his bed, with a rash on his head and chest.
"The plants inside the house lost their leaves," said Doug Schaub, his son.