GM Recalling Nearly 462,000 2020-2022 Pickups and SUVs Including Silverados and Tahoes Because the Back Wheels Can Lock Up

General Motors is recalling nearly 462,000 of its most popular pickups and large SUVs because of a transmission problem that can cause the back wheels to lock up. The recall only involves vehicles with diesel engines. The recall involves 2020-2022 Chevrolet Silverado 1500, 2500 and 3500 pickups, as well as 2020-2022 GMC Sierra 1500, 2500 and 3500 trucks. The recall also includes the 2021 Cadillac Escalade, Chevrolet Tahoe and Suburban and GMC Yukon. According to documents posted on the National Highway Traffic Safety Administration website, a transmission control valve can wear out.

What is Causing the Problem

According to the Recall Safety Report,

"A transmission control valve in some of these vehicles may be susceptible to excess wear over time, resulting in a gradual loss of pressure within the valve that can cause harsh shifting. In rare cases, the rear wheels may experience a momentary lock up. If the rear wheels lock-up momentarily while driving, there is increased risk of a crash.”

The report goes on to explain why the wheels lock up.  “Excessive wear within the transmission control valve body can cause a fluid leak leading to a pressure drop that causes certain valves to move unexpectedly.”

Drivers may notice harsh shifting before the wheels lock up.

The majority of the vehicles being recalled are the larger pickups. There are 66,897 Chevrolet Silverado 1500 trucks included, and 166,541 Chevrolet Silverado 2500/3500 vehicles affected by this recall. Similarly, there are 80,033 GMC Sierra 1500 vehicles affected by this recall and 135,323 GMC Sierra 2500/3500 vehicles.

During the investigation, GM and NHTSA identified 1,888 field reports alleging a “lock up” potentially related to this problem. GM also identified eleven alleged incidents potentially related to the condition, including vehicles veering off the roadway and, in some cases, incurring minor property damage. Three minor injuries were also reported, none of which were associated with a crash.

How GM Will Fix the Problem

The Recall Safety Report says that dealers will install new transmission control software that will monitor the valve and detect excess wear 10,000 miles before the wheels lock up. If wear is detected, the transmission will be limited to fifth gear, preventing wheel lockup, which happens when the transmission downshifts from eighth gear. GM will provide warranty coverage to fix transmissions that have a defective control valve. Owners will be notified of the recall by letter on Dec. 9. Again, it is important to stress that this recall only affects vehicles with diesels engines. Gas-powered vehicles have a different type of transmission

Chevrolet Photo

Mary Conway is a professional automotive journalist and has decades of experience specializing in automotive news analysis. She covered the Detroit Three for more than twenty years for the ABC affiliate, in Detroit. Her affection for the Motor City comes naturally. Her father ran a gas station while Mary was growing up, in Wisconsin.

Follow Mary Conway at @MaryConwayMedia and send her car news tips for future stories.