Vehicle gives warning that steering assist is disabled. I should drive carefully. Also cooling fans run on high and temp gauge reads zero. P0128 I'd code given by computer. When code is cleared vehicle returns to normal operation. I read many, many people have this same problem with no clear correction. Many have replaced thermostat, temp sensors, and problem returns. Sounds like defective wiring to me and if it impacts steering should be an OEM problem to remedy
2020 Chevrolet Blazer engine complaints
Page 3 of 4: complaints 41 to 70 of 74, newest first, as owners wrote them.
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 federal safety agency 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 federal safety agency 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 federal safety agency 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.
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 federal safety agency 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.
To whom it may concern, I purchased a new 2020 Chevy Blazer from the dealership five years ago. Since then I have had to replace my battery twice, radiator and now the thermostat all of which have been done at the dealership. The car and all receipts of the repairs are available for inspection if requested. This most recent mechanical issue with the thermostat included the following; fans blowing on high, no AC, check engine light, steering assist reduced message, and temp gauge on C. The car was immediately (same day) taken to the dealership for investigation. Upon inspecting the car the mechanic found the thermostat sticking open and indicated that it would need to be replaced as it was unsafe to drive. A total cost of $1400. It seemed odd that my car is only 5 years old with 75k miles and needing to have the thermostat replaced so I started researching this issue further. I found several complaints on the www.chevyblazer.org forum from other 2020 Chevy Blazer owners with the same mechanical issue. There is one comment on the forum from a mechanic stating that this issue is caused by a faulty wire harness and will continue to cause similar issues until the wiring is fixed. You can find those comments in the forum on www.chevyblazer.org This continues to be an ongoing issue with this make and model of Blazer with no consistent fix from the dealer. I believe my previous battery and radiator issues are all related. I am reaching out to you for assistance and/or guidance to help get this mechanical issue reported as a recall by the dealer and properly fixed at dealer cost. I am happy to provide any additional support you may need to research this further. Thank you in advance.
Engine fan stuck on high, air conditioner does not work, temperature gauge stuck on cold, driving assist warning light on.
I have had to replace the radiator 3 times since I've owned this vehicle. I see where there are others with the same issue. Now I have to replace the thermostat my first radiator was replaced at 16k miles. This is a safety issue because my car over heated and broke down on the highway left me stranded
Chronic code P0128, causes cooling fans to go on high, AC doesn't work and steering assist reduced. GM calls for the thermostat to be replaced, at the cost of $1400 at my local Chevrolet dealer. Worked fine for two months then code and issues come back. Online forums are full of people with the same problem. Clearly there is an issue with these vehicles with the 3.6l motor.
Continues "reduced steering assistance', thermostat won't register, stay on Cold, a/c blows warm air. We added coolant, replaced battery. Code goes off, within a few weeks comes back on. About to replace the whole thermostat and sensor. Many many blazers having the same issues.
Radiator was found to be leaking. Now thermostat is sticking. This could have caused my engine to overheat and catch fire. I have had a mechanical shop replace the radiator but could not afford to replace the thermostat yet. I had been seeing warning lights and still see warnings after radiator was replaced. They said “Steering Assist Reduced” and “ESC” and the engine light came on. I went to Auto Zone Dec 9th to have them tell me what was wrong. I took to shop on Dec 13th. I have googled several complaints about Chevy blazers having this particular problems. This is apparently a widespread issue that needs to be recalled.
Steering assist warning and engine check light are on. I had an scan done and was told it was the thermostat and coolant temperature sensor which seems to be a common problem. There are no safety concerns to my knowledge. I feel this problem needs to be addressed as repairs are very costly.
The 2020 blazer is having the same coolant temperature problem the 2021 blazer has and the recall needs to be expanded. Thermostat messed up, constantly losing coolant, check engine light, steering reduced
Thermostat is faulty at 55k miles. Purchased 2020 Blazer RS, certified used from Chevy in October 2023. Less than 1 yr later, thermostat is stuck on cold, no ax or heat, drivers assist reduced notice. Same issues as previous documented complaints. The frustration is why this known issue is not covered under warranty or recall! I just had my 50k maintenance service done while this issue was occurring- service told me “well we cleared the codes” , 2 days later check engine is on, temp stuck on cold, fan is over worked and no a/c or heat- and driver assist turns off. The safety issues around causing more engine damage by improper cooling and reduction of driving assistance. Additionally, parking issue with vehicle not recognizing it’s in park and having to wiggle or jam the shifter- car drains battery and won’t lock until resolved. Car is took expensive to have a $1200 replacement not covered under warranty!
2020 Chevy blazer with 50,000 miles just had to have the thermostat housing replaced. Check engine light would everntually come on. But it would say "Steering assist reduced drive with care" When hooked up to the computer it read code P0128. I have the extended warranty and still had to pay over $600 to have this fixed which is completey ridiculous for how new and expensice this car is.
Shift to park issues. Car not reading that it’s in park.
6/12/2024 In Damon Parking lot in Rochester MN. Going less than 10 miles an hr- cars in front of me and behind me looking for a parking spot. Stop and go at times. Went to turn corner to go from one level to the next and my BLAZER took off "like a bullet". No control over accelerated speed- hit outer cement wall and slammed into 2 parked empty SUVS. Could not go any farther. The 2 SUVs slammed into cement wall in front of them. Injuries to both my passenger and myself. I have no idea what happened - it was so fast- I do know I had no control over accelerated rate causing accident. My 2020 Chevy Blazer was totaled- It was inspected by American National Insurance CO. Absolutely no warnings. Police report did not include any witness. Blazer is in the hands of the Insurance Co. Chevy Blazer took off like a bullet - could not stop it!!Police report 24026393 Rochester Police Dept Unable to upload . Checked no police report below so I could continue report.
Esc message on dashboard & all wheel drive disabled & lane assist traction control liggt turns on & parking brake light turns on while driving caused for my electric component to act all crazy including my sunroof I’ve been in the dealer over over try to fix it and that is concerning reason for my safety while u are driving and all those lights come on And yes I have took it to the dealer multiple times to fix this situation And yes the vehicle has been inspected by the manufacturer And yes it has happen before i have a 1 year with the car the problem first came about couple month after I got the car and been having problem since then I bought the car 5/13/23
Approximately three weeks ago, our 2020 Chevrolet Blazer's check engine light came on. It has a little over 63,000 miles on it. I took it to a private service garage where they diagnosed the code as P0128, or coolant system issue. They concluded that it was the thermostat. I did some checking on the warranty and it turns out that the warranty on this car expired at 61,066 miles. I then took it to Serra Chevrolet in Grand Blanc, MI where they diagnosed the same error code, or P0128. They took the car back to give me a service estimate and when they returned they diagnosed not only the thermostat as defective. This has become a common problem with this car and the 3.6 liter engine in particular. We have been told that this is a "known issue" by two different General Motors dealerships, specifically in their respective service departments. However, the owners are now having to pay for the complete replacement, both parts and labor, for these issues. Given the fact that these are a known issue, it seems to me that these need to be elevated to at least a bulletin, if not a full recall. The repair and replacement for the thermostat and sensor is in excess of $1,000. Again, since this is a known issue, it is my belief that General Motors should pay these expenses.
This vehicle is currently on its third radiator since it was purchased, 4 years ago. That’s almost 1 radiator per year. The vehicle also has transmission issues on the highway. The dealer replaced the torque converter but vehicle is still hesitant and bucking on the highway. This vehicle only has 64,000 KM and would cost thousands in repairs if it wasn’t under warranty.
The "steering assist reduced; drive with care" notification began coming on the dash with significant changes in outdoor temperature, as of last fall 2023. The temperature gauge on the dash would then not work and would remain at cold. Eventually the check engine light will come on however all of this will clear when the outdoor weather is stable again. As I live in MN you can imagine there are many variations to our temperatures. This occurred at the beginning of fall 2023, then winter 2023, then spring 2024. It is clear from consult with mechanics that this is all related to the thermostat being stuck open/closed. This is a very well documented issue for Blazers and I would even refer you to [XXX] which has pages and pages of both concerns related to this issue as well as radiator cracks; which I am dealing with also. This car has less than 60,000 on it! The radiators are also obviously faulty in these Blazers as well given the amount of people needing to replace these before 60,000. Some even reporting replacement under 30,000 miles which is ridiculous for a $52,000 vehicle. I would also direct you to a Facebook group of Blazer owners and the complaints about these two issues are rampant. (2019+ Chevy Blazer Official Group) [XXX] I had an appointment at Rosedale Chevrolet in MN on [XXX] and after diagnostics, and all of the above was confirmed. This issue poses a safety risk given the potential impact to the steering assist, air conditioning in hot temperatures, the car overheating and engine damage which WOULD be covered under the powertrain warranty, as well as the potential of being stranded due to a break down. This issue appears to be primed for a class action lawsuit. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Steering assist reduced warning came on as I was driving. Electric steering module has gone bad.Temp gage and AC stopped working as well. No accident yet but this is a KNOWN SAFETY DEFECT that needs to have a recall. The steering wheel could lock up. Force GM to recall this vechile before people die!!
Transmission issue, computer repair, constant issues.
My vehicle needs a new purge pump which is part of the emissions system. This is a common problem on this vehicle so it should be covered by GM since it is part of the emissions system.
The car repeatedly has an error pop up that states steering assist is no longer activated and to drive with caution. The thermostat during this is also fully on cold. The check engine comes on after. The sensor and thermostat are repaired based on the code and problem persists. Same problem all over forums but Chevy refuses to fix as no recall. This is very concerning as the car may randomly go into limp mode while driving on the highway at 70mph putting at risk for crashing. The steering assist is also out putting at further risk. This is despite fixing and clearing the codes shown. This is a known issue that Chevy is refusing to address/recall.
I was driving on express way 96W Left lane busy 5 o'clock traffic Car just died it was stop n go I could have been killed if it wasn't for a man that stopped behind me he couldn't help another person stopped and push the car in N To a grass area where at least I wouldn't be smashed in Called 911 state police inform help van He didn't look at it my friend was there to pick me up Called tow truck they dropped it off at Chevy dealership in Howell Mi
My 2020 Chevy Blazer began demonstrating possible problems with the transmission in November 2021 which have continued to date. The RPMs will rapidly increase and the car will feel as if it is jolting forward. If driving below 20 mphs, when I try to accelerate to a higher speed, the car will drag and then skip forward. I have videos showing this and have taken it to the dealership on two occasions but it couldn't be replicated and no codes show during diagnositics. The car is currently being repaired (at the dealership since 3/18/22) due to 3 separate concerns that are co-occuring which seems quite strange to me. The thermostat has gone bad, causing my check engine light to come on while driving (and having to have it towed). The car is also not recognize my remote key to operate the car. I am also getting "steering assist reduced" notifications while driving. I had the battery replaced 3 weeks ago because that was felt to be the cause of the steering assist notice, but after 1 week the notices started occurring again. I will also occasionally get "ECM" notices while driving. I don't see how all of this could be happening at the same time and it not be indicative of a more major Powertrain issue. I do not feel safe driving the car, even when these separate issues are repaired because I am fearful of the core, underlying cause.
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