GM says the affected vehicles, all manufactured in late 2012, may have been built with a broken parking lock cable or a defective part in the steering column. Those flaws could allow the car to slip out of “park” after the driver has walked away.
The recall includes certain Cadillac Escalades, Chevy Suburbans and Tahoes, G-M-C Yokons and Sierras, along with other G-M vehicles. So far, the car maker says it knows of no crashes or injuries related to the defects.
http://www.knoe.com/story/20505248/recall-your-suv-could-roll-away-while-parked