Defect
On certain vehicles, the transmission control valve body could wear and lose pressure. If this happens, the transmission could shift harshly and cause the wheels to lock up. Note: This recall only affects vehicles equipped with a 10-speed automatic transmission.
Safety Risk
Wheels that lock suddenly could cause a loss of control and increase the risk of a crash.
Remedy
General Motors will notify owners by mail and advise you to take your vehicle to a dealership to update the transmission control module software to detect excess wear in advance of a wheel lock up. If detected, a service engine light would turn on, a message would display in the instrument panel and the vehicle would be limited to fifth gear.