General Motors has issued a recall for nearly 464,000 pickup trucks and sport utility vehicles equipped with Duramax turbo-diesel engines. This is mainly because of a potential safety hazard. The issue involves the transmission control valve; this component can experience excessive wear over time.
This wear can then lead to harsh shifting and, in rare cases, cause the rear wheels to lock up while the vehicle is in motion, according to the National Highway Traffic Safety Administration (NHTSA), as noted by Truck Master in a video discussing the recall.
To address the problem, GM has outlined a two-phase plan. Initially, dealerships will provide a free software update to the transmission control module. This update will actively monitor the transmission control valve for signs of excessive wear.
This software will detect potential issues about 10,000 miles before a possible wheel lock up occurs. As Truck Master explained, “…the software will closely monitor the performance of the transmission control valve – apparently this software can detect excessive wear in the transmission…”
Upon detection, the software will limit the transmission to Fifth gear, reducing the vehicle’s speed to about 45 mph. This action serves as a clear warning to the driver to seek immediate service. Subsequently, the long-term solution involves replacing the affected valve body.
However, GM reports a current unavailability of replacement parts. The company states it is actively working to obtain the necessary parts as quickly as possible. This parts shortage presents a considerable challenge for owners who require immediate repairs. In addition, GM has issued a stop-sale order for the recalled vehicles at dealerships.
Prior to the recall, the company became aware of the transmission problem on June 5, 2024, after a customer submitted a complaint. Following this report, GM started an internal investigation on July 16, 2024.

Truck Master owns 7-8 diesel trucks and most of them are Chevys. According to him, it is really looking bad for GM.
Before these dates, GM possessed knowledge of the excessive wear in the control valve. Unfortunately, they did not consider it a safety risk that warranted a recall. GM was supposed to begin sending owner notification letters on December 9, 2024. You can learn more about this recall by clicking here.
As if that wasn’t bad enough, 450,000 trucks have also been recalled for a brake fluid issue as well.