On a small number of vehicles, a bolt in the rear suspension control arms may not have been manufactured correctly. As a result, the bolt could break. If this happens, there can be a sudden change in rear wheel alignment that could lead to a loss of vehicle stability.
A loss of vehicle stability could cause a loss of control and increase the risk of a crash.
General Motors will notify owners by mail and advise you to take your vehicle to a dealership to replace both rear suspension outer control arm bolts.