General Motors Recalling Nearly 500,000 Diesel Trucks And SUVs

General Motors is recalling approximately 461,839 trucks and SUVs due to a transmission control valve defect that may cause rear-wheel lockup, greatly increasing the risk of a crash.

The affected models include all of GM's big boys equipped with diesel engines: 2020-2022 Chevrolet Silverado 1500, 2500, and 3500 models, the corresponding GMC Sierra trucks, along with 2021 Cadillac Escalade, Chevrolet Tahoe, and GMC Yukon SUVs. Gasoline models are equipped with a different transmission and are not affected by the recall.

According to NHTSA documents, the issue stems from the transmission control valve, which may experience excessive wear over time. This wear can lead to a gradual loss of pressure within the valve, causing harsh shifting. In rare instances, the defect may result in a momentary rear-wheel lockup, increasing the risk of a crash.

To address the issue, dealers will install new transmission control module software designed to monitor valve performance. The updated software can detect excessive wear about 10,000 miles before a wheel lockup condition could potentially occur.

If wear is detected, the software will limit the transmission to fifth gear, preventing the possibility of a wheel lockup, which typically happens during a downshift from eighth gear. Additionally, a service engine light and a reduced propulsion warning message will be displayed on the instrument panel, alerting drivers to the issue. GM has instructed its dealers to halt the delivery of the affected vehicles until the necessary repairs are completed.

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