Chevrolet Blazer loss of power problems

Filed Oct 20, 2026 · Electrical · SC · fire

My 2020 Chevrolet Blazer experienced severe mechanical problems, including stuttering, loss of power, and the engine shutting off unexpectedly while I was driving. The vehicle subsequently would not operate normally. On February 25, 2026, Rick Hendrick Chevrolet Duluth performed a diagnostic inspection and recommended nearly $20,000 in repairs, including transmission-related repairs. However, the dealership did not identify or disclose any alternator fire damage or related electrical safety concerns. In October 2026, an independent mechanic discovered significant burn damage on the alternator. The damage was visible externally, and further inspection of the alternator’s interior revealed additional evidence of burning. I believe this condition may have contributed to the vehicle’s sudden loss of power and shutdown. This presents a serious safety concern because an unexpected engine shutdown while driving can increase the risk of a collision, and an electrical failure involving burning components may present a fire hazard. The vehicle has not been driven since the dealership’s inspection. The damaged alternator has been preserved, and photographs were taken documenting its condition. The component is available for further inspection upon request. I am requesting an investigation into this alternator failure and the associated vehicle safety risks.

Filed Oct 20, 2026 · Electrical, Engine · TX

1. Vehicle completely shut off at a stoplight during the nighttime. The vehicle lost all power including lights, hazard lights, horn and electrical system. Would not start back up for several minutes while sitting in the middle of the highway during the nighttime, creating an immediate safety hazard in traffic. Vehicle self-corrected after a few minutes.

Filed Sep 17, 2026 · Brakes, Engine · WI

Vehicle Information: 2021 Chevrolet Blazer 2.5L engine, VIN [XXX]. Odometer 118000 miles.Description of Incident: While operating the vehicle, the mechanical brake vacuum pump experienced a catastrophic internal failure. The drive gear housing shattered violently without warning, shearing off the end of the connecting engine camshaft. Because this was an instantaneous mechanical failure, the vehicles computer did not trigger any dashboard warning lights, check engine lights, or safe mode protocols prior to the failure.Safety Hazards and Component Damage: First, the total destruction of the vacuum pump caused an immediate compromise to the brake booster vacuum lines, resulting in a sudden, dangerous loss of power braking assistance. Second, the sheared camshaft breached the engine valve cover or head, causing the engines pressurized oil system to instantly dump all engine oil externally onto the ground. Third, shrapnel or violent structural torque from the instant engine seizure punctured or severed the adjacent transmission cooler fluid lines and compromised brake fluid lines, causing total loss of transmission fluid and brake fluid simultaneously.Request for Action: This failure mirrors the exact mechanical defects documented in GM Technical Service Bulletin 21-NA-268 and previous GM vacuum pump recalls like the federal safety agency Recall 19V‑645, which excluded the 2021 Blazer. I am filing this report because the lack of an electronic warning indicator before a catastrophic mechanical brake and engine failure poses an extreme, immediate threat to highway safety. GM must expand recall coverage or issue a Special Coverage Adjustment for this model year. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jul 6, 2026 · Engine, Fuel system · AZ

"While attempting to merge onto a high-speed freeway on-ramp, the vehicle suffered a sudden and catastrophic loss of engine power, rendering it unable to accelerate and creating an immediate life-threatening safety hazard. The vehicle was restarte and driven home, where an onboard diagnostic check revealed an emissions system failure. The dealership later confirmed that BOTH close-coupled catalytic converters on the 3.6L V6 were damaged. The check engine light was a solid light. Not flashing.

Filed Jun 23, 2026 · Electrical, Engine · IN

The vehicle experiences a constant cooling system failure that appears to be related to the thermostat. Beginning at approximately 40,000 miles, the engine cooling fan started running continuously at high speed whenever the vehicle is operating. At the same time, the air conditioning stopped functioning properly and the vehicle began displaying a warning message indicating that steering assist is unavailable or reduced. The vehicle is available for inspection upon request. This condition creates a safety concern because the steering assist warning indicates a potential reduction or loss of power steering assistance, which could increase steering effort and make the vehicle more difficult to control, particularly during low-speed maneuvers or emergency situations. The warning appears during normal vehicle operation and can distract the driver. The ongoing failure of multiple vehicle systems raises concerns about the safe and reliable operation of the vehicle. The problem has been present continuously since first appearing at approximately 40,000 miles and is fully reproducible. The condition occurs every time the vehicle is driven and has not corrected itself. Symptoms include the engine cooling fan running continuously, loss of air conditioning, and a steering assist warning message. Based on reports from other Chevrolet Blazer owners experiencing similar thermostat-related failures, this may represent a common defect that warrants investigation and consideration for a safety recall.

Filed Jun 17, 2026 · Transmission · AL

I am submitting this complaint regarding the transmission in my 2020 Chevrolet Blazer. My vehicle has fewer than 100,000 miles and has experienced significant transmission failure symptoms, including hard shifting, jerking during acceleration, RPM fluctuations, slipping, loss of normal power, and inability to safely reach highway speeds. The vehicle struggles to accelerate properly and at times will not shift correctly into higher gears. Diagnostic trouble codes related to transmission operation have been present, including pressure control solenoid and transmission control faults. Repairs have already been attempted, including replacement of transmission-related components, but the transmission continues to malfunction. Through online owner groups, forums, and discussions with other Chevrolet Blazer owners, I have found numerous reports from owners experiencing similar transmission problems in 2019-2022 Chevrolet Blazers. Many owners report transmission slipping, harsh shifting, torque converter issues, valve body failures, pressure control solenoid failures, and complete transmission replacement at relatively low mileage. These failures create a serious safety concern because the vehicle may hesitate, lose power, fail to accelerate properly when entering traffic, or be unable to maintain safe highway speeds. Drivers and passengers are placed at risk when a vehicle cannot respond normally during merging, passing, or other traffic situations. Owners are frequently being quoted between $7,000 and $12,000 for transmission replacement or repair despite the vehicles being relatively new and often having less than 100,000 miles. Many consumers believe these failures indicate a widespread defect rather than normal wear and tear. I request that the federal safety agency investigate transmission failures in the 2020 Chevrolet Blazer and related model years to determine whether a manufacturing or design defect exists and whether a recall or other corrective action is warranted.

Filed May 27, 2026 · Driver assistance, Electrical · MO

Complete and total failure of the telematics module resulting in loss of self driving, onstar, WiFi, gps, and all connected services. Severe battery drain due to module forcing the vehicle to completely shut down while driving, resulting in loss of power steering and brakes.

Filed Apr 29, 2026 · Engine, Fuel system · SC

Re: Vehicle Safety Defect Complaint – 2023 Chevrolet Blazer To Whom It May Concern, I am submitting a formal safety defect complaint regarding my 2023 Chevrolet Blazer. This vehicle has exhibited multiple system failures that present a serious risk to driver safety and public roadway safety. The vehicle was purchased new on July 20, 2023. Beginning on April 21, 2025, at approximately 27,610 miles, the vehicle developed a progressive defect initially presenting as oil-related issues. Despite multiple repair attempts, the condition worsened and required a full engine replacement in January 2026. Following the engine replacement, the vehicle continued to experience critical safety failures, including engine stalling, reduced engine power warnings, and electronic stability control (ESC) alerts. On April 26, 2026, the vehicle experienced a driver assistance system malfunction in which it attempted to steer off the roadway. I was forced to manually disable the system to maintain control of the vehicle. On April 27, 2026, the vehicle exhibited a fuel system failure, including fuel leakage and fuel odor, along with multiple simultaneous warning indicators: • Reduced Engine Power • Service ESC • Steering Assist Reduced / Drive with Care • Power assist driver system disabled This combination of failures presents both a fire hazard and a loss-of-control risk. Additionally, I was informed by the dealership that a high-pressure fuel line, a one-time-use component, was not replaced during the engine installation. This raises concerns regarding improper repair and continued unsafe operation of the vehicle. The vehicle has undergone multiple repair attempts and a major powertrain replacement, yet continues to present serious safety concerns. Due to these ongoing issues, I do not feel safe operating this vehicle. I respectfully request that the federal safety agency review this matter for potential safety defects that may impact other vehicles of the same make and model.

Filed Feb 27, 2026 · Brakes, Electrical · NY

On two separate occasions the vehicle lost all power while driving. On December 5, 2025 turning on to a main road from parking lot the vehicle shut off with no prior warning lights. Shifted vehicle to park. No power to anything, unable to unlock doors, unable to turn on hazard flashers, stuck in the middle of the road at night. Waited a minute and pressed the start button and vehicle started with no problem. Again, on February 24 , 2026 making a left turn in intersection, without any warning the vehicle shut off… no power at all. Stuck in middle of road with no lights , no hazard flashers ,unable to get out of the car. Few minutes later vehicle started again. The vehicle did not stall while stopped, it completely lost power while moving. Reported problem to West Herr Chevrolet of Hamburg NY , brought vehicle in to dealership on February 25, 2026 and they were “unable to duplicate the concerns” The dealership paperwork states that the vehicle stalled while stopped, this vehicle lost all power while it was moving. We now have the vehicle back in our possession but are extremely concerned for our safety and the safety of others.

Filed Feb 19, 2026 · Electrical, Engine · CA

This submission is an additional report related to the federal safety agency complaint #11714381. At approximately 55,000 miles, my 2021 Chevrolet Blazer experienced a sudden throttle body failure while driving. The vehicle entered reduced engine power/limp mode without warning and acceleration was significantly limited. This created a safety concern while driving in traffic, particularly when merging and crossing intersections. Diagnostic code P2101 (Throttle Actuator Position Performance) was present. A Chevrolet dealer confirmed an internal throttle body failure and replaced the throttle body assembly. Although the repair was completed, this failure occurred at relatively low mileage for a critical engine control component. A sudden loss of acceleration can pose a safety risk depending on traffic conditions. Since filing my original complaint, I have identified multiple similar reports online and in owner forums describing premature throttle body failures in GM vehicles with similar symptoms (reduced power/limp mode and limited acceleration). This suggests the possibility of a broader pattern involving this component. I am submitting this additional report so that the federal safety agency has a complete record of the incident and potential pattern of premature throttle body failures. If this issue is widespread, it may warrant further review or investigation as it affects vehicle acceleration and safe operation.