GM says weight on a key ring or jarring road conditions could unintentionally switch the ignition from the run position to off, causing the engine to turn off or the airbags to fail to deploy during a crash.
"If the key is not in the run position, the air bags may not deploy if the vehicle is involved in a crash, increasing the risk of injury," said a recall notice on the National Highway Traffic Safety Administration website.
A spokesman for the Detroit automaker said GM is aware of five frontal impact crashes in which six people were killed when the front airbags did not activate. There were also 17 crashes with non-fatal injuries involving frontal impact where the air bags failed to deploy, the Detroit News reported.
"All of these crashes occurred off road and at high speeds, where the probability of serious or fatal injuries was high regardless of airbag deployment," GM said. "In addition, failure to wear seatbelts and alcohol use were factors in some of these cases."
The recall affects 619,122 2005-07 Chevrolet Cobalts and 2007 Pontiac G5 models in the United States, 153,310 cars in Canada and 6,130 in Mexico. The Cobalt and the G5 were discontinued in the United States.
GM will notify owners and dealers will replace the ignition switch fee of charge.