Congress ordered the automakers to invent a smart airbag, one that could sense a child and turn itself off, by next year. However, some automakers are now telling the government the bag is not ready and could still do harm.
Ford Motor Company tells CBS News, "the company is concerned about the reliability of (smart airbag) technology."
Chrysler made a videotape showing how its smartest bag can be faked out. The bag turns off when a small grown-up takes weight off the seat.
The smart bags that have been developed to know how much you weigh. They can sense the position of your seat.
They can change the force of the airbag depending on the crash's severity. But the technology hit a wall where it came to one critical point - distinguishing a small grown-up from a child.
Veteran analyst John McElroy says the industry is specifically worried about killing a light adult, say a 105-pound woman, who sits out of position and fools the system into thinking she's a child, or not there.
"What they are terrified about is being forced to put in some sort of technology that could end up killing some of their customers," he says.
Federal regulators watching the development of the smart airbag have agreed to be flexible about next year's deadline, but are demanding 100 percent compliance in three years.
"It is a technological challenge, and the agency believed and still believes the challenge can be met by the industry and its suppliers," says National Highway Traffic Safety Administrator Jeff Runge.
Out of the big three automakers, there is one, General Motors, that claims it has solved the child versus grown-up problem, even for that lightweight grown up moving around.
"Our system is smart enough to know that that it is still an adult seated in that position and that that person should still get an airbag. "
Passengers can protect themselves by always wearing seatbelts and always seating small children in the back. The smartest airbag out there will still not be safer than the lowly seat belt.