The jury returned the verdict Thursday in a Houston courtroom.
Zachary Stevens and his parents had sued GM, claiming a faulty ignition switch in Stevens' Saturn Sky jostled off, causing him to lose control of his car and hit another vehicle, killing its driver.
Attorneys for GM told jurors the accident was caused by Stevens' reckless speeding on a rain-slick road.
The ignition switch can slip out of the on position, making it difficult to steer or stop as the car stalls. GM says it has fixed the problem.
GM won two other ignition cases that were tried earlier this year.