The sleek Infiniti G37 Cindy Marsh bought last August was the car of her dreams, equipped with the latest keyless electronics technology that allows her to start the engine with the touch of a button.
But right away, the system gave her trouble. To get the engine started, she would sometimes have to tap the power button repeatedly. Sometimes it wouldn't start unless she opened and closed the car doors, Marsh recalled.
She eventually adapted to the system's quirks but said that even now she isn't sure how to shut off the engine in an emergency.
"I don't know if I ever read it in the owners manual or not," said Marsh, who lives in Columbus, Ohio.
Old-school car keys appear headed for extinction, as automakers rush to install wireless systems that allow drivers to unlock their doors and start their engines with an electronic fob that they never have to take out of their purse or pocket.
Introduced less than a decade ago on luxury models, the push-button systems are rapidly spreading to all segments of the market, including bargain-priced Kias. The number of models with them as standard or optional equipment has quadrupled in the last five years.
Many drivers don't fully understand how the systems work, however, leaving them vulnerable to potentially serious safety problems.
In complaints to federal regulators, motorists have reported that they were unable to shut down engines during highway emergencies, including sudden acceleration events. In other cases, parked vehicles accidentally rolled away and engines were left running for hours without their owners realizing it.
And although traditional keys all work the same way and are universally understood by consumers, automakers have adopted different procedures for using the keyless ignition systems. As a result, owners may not know how to operate their own cars in an emergency, let alone a rented or borrowed car.
"Where you have a second to make an emergency maneuver, you shouldn't have to search around for the right procedure to use on a switch," said Henry Jasny, general counsel at Advocates for Highway and Auto Safety, a nonprofit group based in Washington, D.C., that pushes for laws to make roads safer.
The risk is considered serious enough that federal regulators and an auto industry trade group are looking at adopting standard procedures.
All of the systems rely on a similar architecture that uses a fob: a small transmitter that communicates with the vehicle's computer. The fob can automatically open door locks when the owner approaches the vehicle, and then the engine can be started with just the push of a power button on the dashboard.
But to shut down the engine while the vehicle is moving, drivers must hold down the power button for one to three full seconds, depending on the make. In some cases, two or three successive taps on the button will work. Mercedes-Benz allows drivers to kill the engine with a single push of the power button, but only if the transmission is in neutral. At least one manufacturer prevents emergency engine shutdowns if the vehicle is moving at less than 5 mph.
Industry officials say that the devices have become wildly popular with buyers and that glitches will be eliminated through the normal course of technological improvements, making new regulations unnecessary.
"We really haven't seen too much confusion with these systems," said Dave Proefke, a vehicle security engineer at General Motors Co.
"As they become more widely adopted, I think we'll find that they converge in how they operate," he said.
Besides offering convenience for motorists, Proefke said, the technology gives auto designers greater styling freedom because there's no longer the need for a key cylinder in the steering column. It also benefits older people who have difficulty removing keys from their pockets or turning a key in a lock.
And "it has that cool factor," said Dan Edmunds, director of vehicle testing at www.edmunds.com, an Internet automobile research site.
Auto safety experts say the industry needs to do a better job explaining the functions of advanced technology to motorists and needs to adopt common operating procedures.
Automakers are offering the systems on 155 models this year, compared with 41 in the 2006 model year, according to Edmunds.com. Ford Motor is planning to make keyless ignition an option in its entry-level 2011 Fiesta, due out later this year.
But some owners say that confusing software rules have put them in peril.
Wally Brithinee was in his 2007 Toyota Avalon last August when it began to speed out of control on Interstate 5 near San Diego. Thinking quickly, Brithinee, president of an electric motor repair business in Colton, pressed the sedan's power button, but nothing happened.
"This car isn't stopping," he told a passenger as he felt panic swelling in his chest. "I really didn't know what to do at that point."
Five terrifying miles later, Brithinee managed to halt the runaway Avalon by braking hard and shifting to a lower gear. He walked away unharmed. All that could have been avoided, he later learned, had he depressed the button for a full three seconds, the emergency shut-off procedure used in Toyota Motor Corp. vehicles.
A keyless ignition system may also have played a role in the Aug. 29 crash that took the life of California Highway Patrol Officer Mark Saylor and three members of his family when a Lexus ES 350 lent to Saylor by a car dealer accelerated out of control to speeds of more than 120 mph before hitting an embankment in suburban San Diego County.
Some safety experts believe that a warning label should be included on the dashboard, telling motorists how to shut off the engine. But industry analysts say manufacturers typically resist installing such labels.
What's more, automakers maintain that shutting off the engine may not be the best option in an emergency, because doing so will cause the driver to lose power steering and possibly braking ability.
Toyota has blamed the San Diego accident on a floor mat that trapped the accelerator pedal. But a September memorandum by investigators for the National Highway Traffic Safety Administration also identified the Lexus' push-button ignition as one of the "significant factors" in the crash and noted that "there was no ignition key" that could shut down the engine or warning label on the power button to explain how to shut off the engine.
In the aftermath of the Saylor tragedy, Toyota issued a recall covering 4.3 million of its vehicles and said it would modify gas pedals, change floor padding and install new software.
Toyota spokesman John Hanson said the company is also discussing internally whether to change the function of its power button.
And Thursday, Toyota launched another recall targeting 2.3 million vehicles, including many of the models subject to the floor-mat recall, saying their gas pedals could stick.
Paul Green, a human factors expert at the University of Michigan Transportation Research Institute, said he sees the issue with keyless technology as part of a growing problem of high-tech features being introduced faster than the industry is able to agree on common operating procedures.
"The amount of research we are doing is not adequate," Green said.
Motorists are confused even when they pay top dollar for advanced features. The Insurance Institute for Highway Safety found in a recent survey that a majority of owners of Infinitis equipped with automatic lane departure warning systems did not know that a button on the steering wheel turned the system on and off.
"They had no idea that they had a button on the steering wheel that could activate the system," said Russ Rader, a spokesman for the institute.
The highway safety administration said in a statement that it has begun to look into possible standards for the keyless systems. And the Society of Automotive Engineers formed a committee in July to examine keyless technology and "study a possible standard on how long the ignition button should be depressed to shut off the engine."
But new federal safety rules or industry standards typically can take years to adopt. The scrutiny is coming eight years after the first system was introduced by Mercedes-Benz.
Beyond safety problems, the push-button technology has some idiosyncrasies that have left motorists stranded but also provided loopholes for car thieves.
In early General Motors vehicles with push-button start systems, owners would sometimes shut down the engines with the transmission still in gear.
That would not electronically lock the ignition system, and thieves soon found they could simply get in the vehicle, push the start button and drive away, said Forrest Folck, a forensic mechanic in San Diego who investigated the issue for an insurance company.
"Cars were being stolen all over the United States," he said.
Larry Stewart, a former Times sportswriter, discovered an opposite problem with the technology in his 2007 Toyota Camry.
After he parked at a Granada Hills restaurant last summer, the car would not start. The tow truck driver who came to Stewart's rescue wasn't surprised, telling Stewart he had been there several times recently for the same reason.
The driver blamed the problem on stray radio signals, possibly from a powerful police or fire station transmitter nearby. He towed the car 100 yards, and it started immediately.
"It's really unnerving that such a thing could happen," said Stewart, who lives in Arcadia.
Even GM engineers found themselves in the same situation when they parked test vehicles at a Detroit-area shopping mall and found that the keyless ignition system was disabled, according to Proefke, the GM expert.
"It was a dead zone," he said.
Proefke said the problem was traced to interference from a nearby nightclub's lighting system, which was broadcasting unlicensed high-power radio signals.