2020 Chevrolet Silverado vehicle speed control problems

“I received a notice via OnStar of a P129 code of a critical issue with engine or transmission system on my 2020 Silverado pickup after I pulled on to the highway. Vehicle reduced engine power warning and engine light came on. I was forced to put vehicle in neutral and restart vehicle several times. This code indicates fuel pump control module being defective. After researching, there seems to be issues with this on the the following; General Motors has issued voluntary emission recalls (such as bulletins N252516900 and N262558690) for the fuel pump power control module on select 2021–2023 Buick, Cadillac, Chevrolet, and GMC vehicles. The issue with my vehicle is the same.”

“1) The vehicle experienced a rear axle/rear-wheel lock-up after the recall-related repair was performed and the same diagnostic codes associated with the initial repair reportedly returned. 2)The rear axle/rear wheels locked while the vehicle was being driven on the highway, creating a significant loss-of-control and collision hazard. A sudden drivetrain/axle lock-up at highway speed causes the vehicle to stop or behave unpredictably, potentially resulting in a severe collision 3) Yes. Huffines Chevrolet performed the initial recall-related repair and subsequently the same diagnostic codes reportedly returned after said repair 4) The vehicle has been inspected by 2 Chevrolet dealerships, including Huffines Chevrolet and El Dorado Chevrolet/Motors. The matter has also been reported to GM Customer Assistance under Case No. 110236243 5) Yes. Diagnostic codes associated with the recall-related issue were present when the vehicle was initially taken to Huffines Chevrolet on August 10, 2026. Huffines performed recall-related repairs, including replacement of the transmission module as part of the attempted repair. After the vehicle was returned, the problem recurred.…”

“Unknown which system failed. While driving on the freeway, truck lost power for a few seconds. Dash lights turned off and back on. Our safety and the safety of others on the freeway were at risk as we had no control of the vehicle. Have not had the truck checked for the problem. Scared to drive it. No warnings appeared.”

“The contact owns a 2020 Chevrolet Silverado 1500. The contact stated that while driving at an undisclosed speed, the RPM became extremely elevated. The accelerator pedal was depressed; however, the vehicle failed to respond. The vehicle was turned off and restarted. No warning lights were illuminated. The vehicle was towed to the local dealer, where it was diagnosed and it was determined that the torque converter was inoperable, and that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline. The approximate failure mileage was 80,000.”

“Intermittent issue where info says brake failure/steering assist not working/limited speed to 43 mph. Very dangerous if you’re on the interstate. Becomes hard to steer, brakes don’t work, brakes start burning up. Have to carry tools with me to reset ecm. Very common problem with Silverado with 5.3 gas engine. Chevy needs to fix this issue before someone gets killed. I would give them my truck back if I could.”

“My truck started acting sluggish like the parking brake was applied while driving. At a traffic light I put the vehicle in park applied and released the parking brake. I put the vehicle back in gear an let off the brake. The vehicle did not move so slightly pressed the accelerator. The vehicle still acted as if the brakes were applied. I could feel the slight movement and torque being applied but only slightly lurching. The traffic light turned green so I proceeded up to 45mph. A vehicle in front of me slowed to make a turn. Applied the brakes and nothing happened. I pressed the brake so hard that I lifted myself off the seat. I swerved to miss the vehicle avoiding a collision. Then warnings started popping up; "brake system failure max speed 62mph", "brake system failure max speed 42mph", Brake system failure", service traction control", "service trailer baking system". among others I was too busy to see all of them. I coasted to a stop in a nearby parking lot with visual and audible warnings still going. I shut the vehicle off then restarted it. Some warnings remained like traction control and the engine light. The vehicle appeared to be operating correctly…”