- GM is recalling 44,787 trucks and SUVs over a transmission issue.
- Due to excessive valve wear, the rear wheels can lockup while driving.
- There are two recalls and they’re being addressed with software.
General Motors has issued two separate recalls for a transmission control valve that can cause the rear wheels to lockup. The issue affects a mix of full-size SUVs and pickups, and while the risk appears limited, the potential consequences are serious enough to prompt action.
The first recall impacts 43,732 full-size SUVs from the 2022 model year including the Chevrolet Tahoe / Suburban, GMC Yukon / Yukon XL, and Cadillac Escalade / Escalade ESV. The NHTSA says a transmission control valve in the ten-speed automatic is susceptible to excess wear over time, which can cause a gradual loss of pressure. This can result in harsh shifting or a rear wheel lockup in “rare cases.”
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GM became aware of the issue last fall after a customer alleged their transmission locked up, causing them to lose control and crash into a guard rail. The automaker opened an investigation and noticed the incident echoed an earlier recall involving excessive transmission control valve wear, which could cause a momentary (<150ms) lock up of the rear wheels.
Why Do The Wheels Stay Locked?
The new investigation found a “distinct condition” that is specific to vehicles equipped with a ten-speed automatic featuring electronic transmission range select. In these models, “excessive wear within the transmission control valve body could cause the rear wheels to remain locked until the vehicle comes to a stop.”
GM found 13 reports potentially related to the issue and believes the problem is limited to transmissions built between April and September of 2022. These are said to have “unique internal hardware that may increase the rate of wear in the transmission control valve.” They also weren’t equipped with software that monitors valve performance and detects excess wear.
Only 1% of the vehicles are believed to have the defect and GM will address the problem by installing new transmission control module software. It’s designed to detect excess wear approximately 10,000 miles (16,093 km) before a wheel lock up could occur.
Once the software detects something is wrong, the transmission will be limited to fifth gear to prevent the possibility of lock up, which occurs when downshifting from eighth. Drivers will also be notified by a service engine light as well as a warning message.
Recall Number Two (In More Ways Than One)
The second recall is much smaller and involves 1,055 full-size pickups. This includes the 2020-2022 Chevrolet Silverado 1500 and GMC Sierra 1500 as well as some 2500 and 3500 models from both brands.
They’re suffering from recall redux as they might have been repaired incorrectly under a previous campaign from 2024 that involved 461,839 vehicles. This is the earlier recall mentioned above and it involved valve wear and momentary wheel lockup.
GM opened an investigation last September after they discovered an “issue” with their Global Field Action Management system. They wanted to see if the problem could have allowed dealers to install incorrect software versions as part of the recall process.
The automaker reviewed 56 different recalls and didn’t find any evidence of incorrect software installation. However, on January 19 of this year, an investigator discovered that some vehicles may have been affected due to a previously unknown delay in the software rollout.
100% of these vehicles are believed to have the incorrect software and dealership techs will check to see which version they’re running. If needed, they’ll update the software.
