2020 CHEVROLET BLAZER Complaints

The contact owns a 2020 Chevrolet Blazer. The contact stated that while attempting to park the vehicle, the shift lever became inoperable. The contact stated that the shift into park message was displayed. The vehicle was taken to the dealer, where it was diagnosed and determined that the shift assembly had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 20,500.

The contact owns a 2020 Chevrolet Blazer. The contact stated while driving at approximately 55 MPH and driving up an incline in the road, the check engine warning light had illuminated. The contact stated that the vehicle was shuddering. The contact stated that the failure only occurred while driving uphill. The contact had only recently taken the vehicle to a local dealer because the check engine warning light was illuminated. The vehicle was diagnosed, and the dealer determined that the thermostat and the engine control sensor needed to be replaced. The vehicle was repaired. The contact stated that approximately 1,800 miles after the first repair, the check engine warning was illuminated again. The vehicle was taken back to the same dealer. The vehicle was diagnosed, and it was determined that the air flow shutters had been damaged and needed to be replaced. The vehicle was not repaired. The manufacturer was informed of the failure and had referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 97,000.

To Whom It May Concern, I am writing to formally file a complaint regarding ongoing and persistent issues with my 2020 Chevrolet Blazer. The vehicle has exhibited repeated problems that I believe may indicate a broader safety or mechanical defect, and I am requesting that the NHTSA investigate these concerns further. Since purchasing the vehicle, I have experienced the check engine light turning on and off repeatedly, without consistent resolution. The following issues have occurred over time, all seemingly related to the engine or control systems: Engine Cooling System Failure: The first major issue involved the engine cooling system. This caused the vehicle to overheat and required service. I was concerned about the potential for engine damage or fire risk due to excessive heat. Variable Valve Timing (VVT) System Malfunction: Shortly after the cooling system issue, the vehicle began experiencing problems with the variable valve timing system. This not only affected performance and fuel efficiency but also caused the check engine light to illuminate again. Steering Control Assist Sensor Warnings: Most recently, the steering control assist sensor has started to malfunction, with warnings frequently popping up on the dashboard. This has impacted steering feel and raises serious safety concerns. Despite multiple service appointments and repairs, these problems persist or reappear. This cycle of temporary fixes without a lasting resolution is both frustrating and concerning from a safety standpoint. I am requesting that the NHTSA look into whether these recurring engine and control system issues are part of a known defect or recall-worthy problem affecting the 2020 Chevy Blazer. Thank you for your attention to this matter.

Car gets “assisted steering is turned off. Drive with caution.” Warning, temperature gauge in vehicle remains at zero/cold. Engine fan runs at full blast. Sensor gauge/thermostat is broken.

The thermostat is getting stuck open and giving me a reduced steering assist error. My safety was put at risk because of the steering assist being reduced. The problem has not been reproduced but there are many issues online about the same model, year, and mileage all having the same issue. The component is going to be inspected by a service manufacturer. There were no warning lamps prior to error.

Ongoing Engine and Steering Sensor Issues – 2020 Chevrolet Blazer I am filing a complaint regarding repeated safety and mechanical issues with my 2020 Chevrolet Blazer. The vehicle’s check engine light frequently turns on and off, and I have been informed by technicians that it is related to the thermostat system. This issue negatively affects the vehicle’s performance and reliability. Additionally, the “Steering Assist is Reduced – Drive with Care” warning continues to appear while driving, even when weather and road conditions are normal. This error is reportedly due to a steering control assist sensor, and it raises serious concerns about the safety and handling of the vehicle. The alert causes uncertainty and could potentially impact the power steering functionality, creating a hazardous driving situation. These issues have occurred multiple times despite maintenance, and they appear to be part of a broader pattern of defects affecting other owners of this model year. It is unacceptable for a vehicle this new to have persistent problems that affect both engine operation and steering safety. I urge the NHTSA to investigate these recurring issues with the 2020 Chevy Blazer’s thermostat system and steering assist sensor to determine whether a recall or manufacturer intervention is warranted. Safety should not be compromised due to what seems to be systemic defects. Thank you for your attention to this matter.

What component or system failed or malfunctioned, and is it available for inspection upon request? Multiple components in the engine timing and transmission system have failed. These include: Camshaft actuator solenoid valve failed twice (at ~30,000 and ~60,000 miles), each time with different DTC codes. Camshaft positioning sensor failed, triggering P0024 (“timing advanced and bouncing around”). Timing chain tensioner spring failed, requiring re-timing. Camshaft carrier case gasket experienced a major oil leak at 59,000 miles. Thermostat failed. Battery was replaced, but no diagnostic testing was performed—only code clearing. At 82,000 miles: Torque converter has failed, transmission fluid is tarnished, and the radiator is leaking internally. Yes, the vehicle is available for inspection upon request and has been registered as non-operational. How was your safety or the safety of others put at risk? The vehicle exhibited repeated hesitation, delays when accelerating, and revving while braking. In stop-and-go traffic, it now sputters as if it may stall. These behaviors create unsafe driving conditions, especially at intersections and in congested areas, putting both myself and other drivers at risk. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. The torque converter failure and transmission issues were confirmed by National Transmission in Long Beach, CA. Prior component failures were confirmed by Martin Chevrolet, who performed both camshaft actuator solenoid valve replacements under warranty. Multiple DTC codes were recorded and cleared, but no electrical testing was performed. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? The vehicle has been serviced by authorized GM dealerships, but GM did not escalate the issue to their TAC (Technical Assistance Center) or assign a field engineer, in violation of GM's internal escalation policy. No inspections

Failure of either coolant temperature sensor or thermostat or both. The A/C is disabled, the temperature gauge does not function, and a message appears on the dash display regarding steering assist not working. With all these issues, it’s impossible to feel safe driving any distances, not knowing whether the vehicle will overheat and damage the engine or other components, or if the steering will actually fail. Both parts have been replaced, at the time, May 4, 2025.

The thermostat has failed, causing hot air to blow into the car. This is a known and common issue with the 2020 Blazer.

In March 2025 a Steering assist reduced warning came on briefly. Over the next several weeks intermittent. April 2025 Engine warning light came on. 4-14-25 Went to ToddWenzel Chevrolet for diagnosis to be told the Thermostat needs to be changed and due to a small amount of crystallization on the radiator that as well. I had just had oil changed and fluid levels topped off that morning at Parkway express who did not identify concerns. 4-15-25 brought to Parker Brake who diagnosed and identified there was a glitch that prompted the warning and they can tell that fired when not driving, temp 125Degrees. "it may have been parked cooling down". They noted not need for additional service. Thermostat fine and no evidence of radiator leak. They cleared codes/engine warning. After about a week experiencing intermittent assist reduced warning again. I am understanding that this is a known problem w/ these Blazers and changing thermostat for many does not work. Where does this leave me? GM needs to help with the cost and figuring this out. I am concerned about sudden failure of something while driving that could be unsafe for myself/others.