2020 Chevrolet Silverado 1500: sudden loss of power

Filed Oct 26, 2026 · Engine · CA

Incident: Twice our Chevrolet Silverado 2020 Duramax has experienced while operating, sudden with no warning "reduced engine power" and "check engine light" the engine sounds very different and does not operate as it should and presents a safety issue when you are driving and traveling at a high rate of speed. These incidences occurred on 10-4-2026 and 10-23-2026. The vehicle experienced a sudden failure of the engine coolant control valve, triggering Diagnostic Trouble Code P1006. This component failure restricts proper engine thermal management and poses a risk of sudden engine overheating while driving. General Motors has formally acknowledged this identical part failure as a chronic manufacturing and safety defect via Special Coverage Bulletins N252508341 and N252508340, which extend warranty coverage to 15 years/150,000 miles. However, GM has arbitrarily excluded the 2020 model year from this coverage, despite the vehicle utilizing the exact same defective part assembly number as the covered 2021-2023 models. This identical component failure across model years constitutes an unaddressed defect pool that requires immediate regulatory expansion to protect consumers from unsafe engine component failure. please fix this situation TY

Filed Oct 23, 2026 · Brakes, Electrical · TX

It said on the dash, "Brake System Failure 43MPH Top Speed," "Service ESC," and lights on were the ABS light, BRAKE light, Engine Light, and Wheel Traction light. My wife and my [XXX] son's safety were at risk while driving on a busy 75mph highway and trying to turn around and make it home as the brakes did not work and having to cross busy streets. It was not able to reproduce but my local mechanic found the bulletin from way back that had not been addressed by GM after numerous times to a dealer for other repairs. I then took it to a local GM dealer that confirmed software update was not applied and they did the repair and I was charged to pay even though this was a known GM issue that never contacted me about this potential fatal random occurrence that could happen after I have taken great care of this truck. There not any warnings before randomly losing power on the highway once she hit 60mph on the on ramp and just started failing slowly. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 12, 2026 · Engine · IN

I was driving the vehicle at around 50MPH after leaving a set of traffic lights when the engine lost all power and a series of warning lights came on. I pulled over safely to the side of the road and had the vehicle towed to a local vehicle mechanic shop. On investigation the engine had seized and a number of internal components had failed. The engine/vehicle I have owned since new and had approximately 103000 miles on it at the time of the incident.

Filed Oct 7, 2026 · Acceleration, Fuel system · TX

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.

Filed Sep 1, 2026 · Engine · WY

My 2020 high country with a 6.2 l is 6 months away from the recall. Driving on the interstate with my family coming out of devil's Tower lost all power!!. I just replaced my motor at 60000 miles total engine loss catastrophic bearing failure!! This is the exact sameproblem from the 2021-2024 recall on the GMC 6.2liter

Filed Aug 28, 2026 · Transmission · PA

Purchased used in 02/2022. Pickup started to shutter when shifting at 35-45 MPH. Took it to Turnpike Chevy who found thrust bearing in reaction carrier broken and damaged planetary gear set. They replaced the reaction carrier ASM and Reconditioned the transmission ASM. Replaced the valve body ASM. Took to John Sauder Chevy numerous times between July 19 2024 and July 7 2025 due to the shutter when shifting having returned. They tried the GM approved fix of flashing the computer to reprogram and kept saying they could not duplicate. On June 18, 2025 while towing a trailer on the highway while going highway speeds in the middle of rush hour traffic the transmission suddenly started making a shrill noise. Transmission disengaged and lost power. John Sauder Chevrolet found a broken oil pump drive and drive gears on the 10L80E transmission. GMC refused to replace the transmission and now it is out of warranty and starting shutter again when it shifts

Filed Aug 28, 2026 · Electrical, Steering · MI

On July 22, 2026 took truck to dealership for oil change and reported getting random (trailer brake, power steering) service alarms. Was told it might be a ground strap issue and was sent on my way. After investigating, there is a GM service bulletin (#23-NA-201) on the issue but does not cover my truck. After a week of vacation, began driving truck again and alarms became more frequent, including loss of power steering and jerking of steering wheel while driving. Arranged with dealership to replace the ground strap (at my expense). By the time they could schedule, the alarms were constant and the truck had completely lost power steering. One of the power steering failures nearly resulted in an accident while turning.

Filed Aug 28, 2026 · Electrical, Engine · 10,000 miles · FL

The contact owns a 2020 Chevrolet Silverado 1500. The contact stated that the infotainment center intermittently went black, and there was water leaking into the vehicle through the top and lower center of the front windshield and the rear windshield. The vehicle was taken to a dealer, where the rear windshield was replaced without a diagnostic being performed; however, the failures persisted. Additionally, the side view mirrors intermittently failed to unfold when starting the vehicle. The contact stated that while driving approximately 40 MPH, white smoke emitted from the exhaust, the vehicle hesitated, and it lost power. The Check Engine warning light illuminated, along with "Service Electronic Stability Control", "Trailer Brake System", "Steering Assist Reduced", "Service Brake Assist", and "Brake System Failure" messages, and the vehicle failed to exceed 40 MPH. The vehicle was towed to a second dealer, Arcadia Chevrolet Buick (210 S Brevard Ave, Arcadia, FL 34266), where it was diagnosed that the lifter and torque converter had failed. The lifter and torque converter were replaced, and the system was flushed. Approximately 800 miles later, the engine failed again. The vehicle was towed to an independent mechanic, who diagnosed that the torque converter and transmission had fractured. The torque converter and transmission were replaced; however, the warning lights and messages illuminated again, and the vehicle continued to hesitate when driven over 42 MPH. After being parked for a few days, the warning lights were no longer illuminated and the mirrors opened, but the engine hesitation persisted. The vehicle was not further diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was approximately 10,000.

Filed Aug 27, 2026 · Engine, Transmission · NM

Vehicle: 2020 Chevrolet Silverado 1500 4x4 LT (5.3L V8 Engine) Component: Engine (Piston Rings, Lifters, and Motor Assembly) / Powertrain Component Availability: Yes, the failed components/vehicle are available for inspection upon request. What Happened and Safety Risk: While operating the vehicle on Prince Street in Clovis, NM, the engine suddenly began knocking violently without any prior warning or symptoms. Immediately following the mechanical failure, dashboard warning lights illuminated (including the Check Engine light, ABS, and Traction Control) and the vehicle dropped into "Reduced Engine Power" mode. This caused an immediate and hazardous loss of acceleration on an active roadway, forcing an emergency maneuver to navigate out of traffic and pull over safely. This sudden powertrain failure poses an unreasonable and severe safety risk to the driver and surrounding traffic. Confirmation and Inspections: The mechanical failure has been confirmed and diagnosed by Hamilton Chevy in Portales, New Mexico, and Sanders Repair Services in Portales, New Mexico. The vehicle and components have not been inspected by the manufacturer, police, or insurance representatives. There were no warning lamps, messages, or symptoms of any kind prior to the sudden failure.

Filed Aug 11, 2026 · Acceleration, Electrical · CA

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.

Filed Jun 24, 2026 · Engine · NE

while driving pulling a trailer with my kid in the car engine began knocking and lost power. upon investigation it was a failed lifter causing bent pushrod

Filed Jun 20, 2026 · Engine · CA

I am filing this complaint regarding a major engine failure in my 2020 Chevrolet Silverado 1500 equipped with the 5.3L V8 engine. At approximately 56,000 miles, my vehicle experienced a failed valve lifter, resulting in loud engine ticking, a check engine light, loss of power, and unsafe driving conditions. The vehicle was no longer operating properly and required immediate repair. Although the vehicle had been regularly maintained and had relatively low mileage for such a significant engine issue, I was informed that the failed lifter damaged the camshaft and related engine components, requiring extensive repairs. The total cost of the repair was $6,180, which I paid out of pocket. My Silverado was just outside Chevrolet's 5-year/60,000-mile powertrain warranty period by time, despite having only 56,000 miles. A major internal engine failure should not occur on a well-maintained vehicle with such low mileage. After researching this issue, I discovered that lifter failures involving the Active Fuel Management (AFM) and Dynamic Fuel Management (DFM) systems in GM's 5.3L engines have been widely reported by other Chevrolet Silverado owners. This indicates a potential design or manufacturing defect rather than normal wear and tear. I am requesting that General Motors provide reimbursement or goodwill assistance for all or a substantial portion of the $6,180 repair cost. I believe customers should not be responsible for paying thousands of dollars to repair a known issue on a low-mileage vehicle. I respectfully request that this matter be reviewed and resolved promptly.