The vehicles affected are equipped with diesel engines and may experience rear wheel lockup, increasing the likelihood of an accident.

The recall is targeting specific models, including the Chevrolet Silverado and GMC Sierra 1500, 2500, and 3500 pickups from model years 2020 through 2022. Additionally, the recall affects the 2021 Cadillac Escalade, GMC Yukon, and Chevrolet Tahoe and Suburban.

According to documents released on the National Highway Traffic Safety Administration (NHTSA) website, the issue stems from a transmission control valve that can deteriorate over time. In rare instances, the valve may fail entirely, leading to rear wheel lockup. Drivers might notice harsh shifting prior to experiencing any wheel lock issues.

GM's solution involves dealers installing new transmission control software designed to monitor valve wear, detecting excessive wear approximately 10,000 miles before potential wheel lockup. If excessive wear is identified, the system will limit the transmission to fifth gear, thereby preventing lockup, which typically occurs when downshifting from eighth gear. GM will also provide warranty coverage for transmissions with defective control valves.

Owners of the affected vehicles will be officially notified by letter on December 9. The recall follows an owner complaint discussed with U.S. safety regulators in January, leading GM to initiate an investigation in July. In September, the investigation uncovered 1,888 reports of wheel lockup related to the defective valve, along with 11 related incidents, including cases where vehicles veered off the road, resulting in minor property damage. Three minor injuries were noted, though GM clarified that these injuries were not linked to any crashes.