ABC News Investigation: The Risk of Keyless Ignitions

— -- A keyless ignition uses a push button in your car to start the engine instead of a key. It’s a feature that’s standard equipment on many new vehicles, but consumer safety advocates say keyless ignitions could pose a danger if you walk away with the fob and forget to turn off the engine.

Noah Kushlefsky is an attorney who has represented several families whose loved ones died from carbon monoxide poisoning after the key fob was removed and the car was left running. "When you're disassociated from the car by removal of the mechanical key, it's an easy step to forget" Kushlefsky said. "It's a senseless situation that should never occur and should never have occurred."

Most keyless ignitions allow drivers to walk away from their car with their key fob and leave the motor running. There are an estimated 5 million keyless cars like this on the road, according to a lawsuit against 10 automakers filed in August in a federal court in Los Angeles — which critics say could put your family at risk.

That’s exactly what happened to the parents of Cesare Fontanini, 50, of Highland Park, Illinois. Often after his shift as a lieutenant for the Highland Park Fire Department, he would stop by his parents’ house to have an espresso. In June 2015, that ritual changed forever.

He found both his parents — Rina Fontanini, 76, and Pasquale Fontanini, 79 — dead after they left their car running in their attached garage.

“It’s etched in your brain for the rest of your life. And a moment like that, that is a game changer in life,” Cesare Fontanini told ABC News’ Alex Perez.

The 2013 Lincoln MKS that his parents drove had a push button ignition. That model makes an audible warning if someone leaves with the key fob while the engine is running, but investigators said that, despite that, Rina Fontanini left the car running. Officials said carbon monoxide from the engine built up in the garage and seeped into the house, eventually killing the elder Fontaninis.

“I was unaware that there was a problem with keyless ignitions until this happened to my parents,” Cesare Fontanini said.

To find out how quickly the carbon monoxide fumes in a running car could turn fatal, ABC News conducted a demonstration with Tom Feiereisen, a forensic engineer specializing in carbon monoxide, to monitor carbon monoxide levels from the exhaust of a car left running in a garage. The Bay Shore Fire Department on Long Island in New York was there to help keep participants safe.

An ABC News producer drove a 2015 Chrysler 300 — one of many vehicles on the market with a keyless ignition — into the garage and took the key fob with him as he exited the running vehicle. Watch the demonstration in the video above.

The producer said he heard no alarm outside the car, and as the demonstration continued, there was no automatic shut-off.

The freestanding garage used in the demonstration was more ventilated than an attached garage. Therefore, ABC News covered its vents to mimic an attached garage. Every 30 minutes, Feiereisen checked the carbon monoxide levels in the garage with a gas analyzer.

After about 2 1/2 hours, Feiereisen said, “We’re currently at 890 parts per million, and that could be ... lethal, given a long enough exposure.”

And about 4 1/2 hours into the demonstration, the level of carbon monoxide in the garage was highly lethal.

“If you were to go inside this garage right now and close the door, you would feel the effects immediately, and you would probably lose consciousness within five to 10 minutes, and death would follow shortly thereafter,” Feiereisen said.

“If this was an attached garage you would get carbon monoxide leaking into the house, almost certainly get lethal levels within the house,” he added.

At this point, Chief John Ippolito Jr. of the Bay Shore Fire Department became worried that the demonstration would become too dangerous if continued, so the test was stopped. Firefighters with masks and safety gear approached the garage.

The firefighters opened the garage door and used several fans to air out the garage and make it safe again.

Most cars with a keyless ignition have some kind of visual or audio alert when the car is left running with the key fob not in the car. Some cars have an automatic shut-off. The 2015 Chrysler 300 used in this demonstration makes a beeping sound in the car, but critics say that’s not much use if no one is in it.

Chrysler told ABC News its cars “meet or exceed all applicable federal safety standards.”

Critics said even an alert that sounds outside a running car isn’t enough and are calling for a standard automatic shut-off, which is on only a few models.

“If you know it’s a safety risk and you have an easy way to fix the problem, then why wouldn’t you do it on all cars? Why are there cars still being purchased by the public that have this risk?” said Ted McNabola, a lawyer who represents the Fontanini family in a lawsuit against Ford, the maker of the elder Fontaninis’ car.

The National Highway Traffic Safety Administration proposed a rule almost four years ago that would require a brief but piercing alarm but not an automatic shut-off if someone leaves a car with the key fob while the engine is running.

However, the Alliance of Automobile Manufacturers, which represents 12 automakers, says it’s opposed to the proposed rule.

“No rationale has been offered for concluding that the proposed audible alarms would actually reduce the identified risks of carbon monoxide poisoning or rollaway,” the organization said in 2012.

Today the Alliance of Automobile Manufacturers told ABC News that its position has not changed and that auto safety is its top priority. It says it continues to work to develop best practices.

NHTSA officials say they are reviewing public comments and plan to issue a final rule in February.

Ford, the the maker of the Fontaninis’ Lincoln MKS, told ABC News in a statement, “Ford takes the safety of our customers very seriously; the keyless ignition system has proven to be a safe and reliable innovative feature that has been well received by customers. Ford vehicles equipped with keyless ignition alert drivers when the driver’s door is opened and the vehicle’s engine is running.”

The company added that many of its current models with keyless ignitions have an automatic shut-off feature, which turns off the vehicle after 30 minutes of inactivity.

Cesare Fontanini hopes his efforts will help educate others about the risk.

“It’s just a matter of educating anybody who does buy any keyless ignition cars so this doesn’t happen,” he said. “This was a senseless accident. It could have been prevented. Hopefully ... it is prevented for future consumers buying cars.”

ABC News’ Thomas White, Hannah Yoo, Brian Broder and Angel Feliciano contributed to this report.