2020 Chevrolet Blazer Complaint Log

The blazer's check engine light came on and I had it scanned. The code was PO128 indicating that the engine coolant temperature is consistently below the thermostat regulating temperature. We are also getting a message on the vehicle that states the steering assist is reduced, drive with care. The car is also blowing hot air when the AC is on, the temperature gauge is staying at the lowest setting and the fans are running full blast. This seems to be a very common problem with the Chevrolet Blazer.

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

When car is parked and shifted to Park massage is sent put car in Park.was a shifter problem dealer fix for 463.00.58000 mi. 2020 Blazer

Almost every time I start the car up it asks me if the vehicle is a Demo. I will sign in as a user and identify the vehicle and keys, but it seems to lose some of the information when it is turned off. It has happened hundreds of times.

when you put your Blazer in Park you get the warning light and chime to 'shift it into park'. So far it has happened to me 5 or 6 times in the past couple days. I can jiggle the shifter handle to get the chime to stop but it has me concerned. I have seen numerous posts about this same problem.

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.

I have an oil leak and now they are saying both of my camshaft housing gaskets are leaking it's going to take weeks to repair cause it's such a major leak

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.

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.

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.

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

Steering assist reduced warning is on all the time. Fan is on overdrive and thermostat needle on cool all the time. Leaking camshaft actuator solenoids

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 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.

Blazer was brand new purchase, I have experienced the following issues so far (several issues appear to be common based on internet searches): 1. Oil pan replaced 4 years 2. Thermostat replaced around same time, this impacted steering 3. Today I replaced a transmission seal for $600, looks like a recall was issued on bolts, my vin was not in population 4. At todays appointment was told the radiator is leaking and I will need a new radiator.

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.

Coolant temperature would not read, steering assist malfunctioning, air conditioner intermittent. Wiring harness for sensors loomed together with coil pack wiring interrupting signals.

Engine fan stuck on high, air conditioner does not work, temperature gauge stuck on cold, driving assist warning light on.

I started receiving the message “steering assist reduced, drive with care” although I’ve noticed no reduction in power steering. This has happened multiple times. The A/C stops working, the Temperature Gauge moves to 0 degrees and the engine fan goes to maximum speed. I have noted that this is a common issue with the 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.

Very bad clunnk on driver side when hitting any bump on the road and it's loud.dealer ship sold me the car like that . Electrical issue gauge cluster radio cluster turn signals your first camera anything that works off the instrument cluster of the radio TV screen goes off while I'm driving comes back on hit a bump it comes back on no headlights driving at night time. The dealership sold me the car like this.

Where do I start. Spring of 2024 I believe, less than 55,000 miles, my transmission went out. No warning. I just went out to my vehicle to go to work and when I put it into reverse, my vehicle make a awful noise, jerked forward almost going into my garage door, then wouldn't move.. I put it back in park, tried to put into reverse again and it wouldn't go. It was stuck in park. Had to get it towed to the dealership where they advised me the transmission went out. It was covered under the drivetrain warranty, but the GM warranty doesn't cover rental. It took almost 4 weeks for GM to approve for a new transmission due to parts being on back order to rebuild my transmission. Several months later, I was driving down the road when the ESC light and then it said "shift to neutral & press start" and I lost power. I coasted into a parking lot, got it fired up, but had no air conditioning (of course it was summer). Took it to the dealer and they said my radiator and A/C Compressor had to be replaced. Luckily my extended warranty covered the $5000 repair. Now 4 months later I got "steering assist reduced, drive with care" with codes. Took to shop and the codes basically was the temp was to low, but the shop couldn't find anything wrong. Cleared the codes and so far so good, but now my ESC light pops on once a week again. I don't even have 60,000 miles on my vehicle.

Check engine light came on, gave error code P0128

Thermostat failure. No a/c, no power steering, engine light on.

I purchased this vehicle in March, 2025 from a used dealer. When I got it, I noticed the vehicle was leaking oil on my garage floor. I took it back to used dealer who also agreed there is a leak but couldn't detect it. They sent me to Chevy Dealer. It has been 3 months now and dealer states the transmission has a seal leak. It seems like a similar recall on same year and model, however my vehicle is not listed as a recall. Why isn't there one?

When putting the car in park the car don’t recognize it’s in park cause the car to stay running.

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

Cooling ran would never shut off, 'Steering Assist Reduced Drive with Care', the smell of sweet syrup (coolant), and the temp gauge would not leave 'C'. All of this happened at once. Brought it in as it was subsequently throwing codes. Chevy Heiderbrecht dealership said that the radiator seal at 53k is completely eroded away and needs to be replaced. They said this is a very common issue with these cars (2020 Blazer/Original Owner), and looking online there is a plethora of people with the exact same issue (low mileage, complete radiator replacement due to seal going bad on upper driver side). This is insane, you spend 40k on a car, maintain it well, and the parts fail this prematurely with no available recall? Now I am stuck with an $1,800 bill with no legal recourse? I mean the dealership said it is a widely known issue, and GM has admitted that the seal is bad, but there's no consumer protection from this big of a company? Only thing covered under powertrain warranty is the thermostat (wow thanks GM!) Thanks for any help you can provide.

On Saturday, March 8, 2025 I was crossing a busy intersection when my car shut off completely and accelerated into oncoming traffic almost causing a collision or fatality. My brakes locked and steering wheel locked. I had to put the emergency brake on in order for the car to come to a stop. We got out of the car in the middle of the street and ran for safety. Scariest experience I’ve ever been in especially with my family in the car!!

Frequently when shutting off my Blazer, I will get an alert that the vehicle is not in park. I have to squeeze and jiggle the shifter in order to get the alert to go away. On several occasions, when I have turned the engine on and back off again without ever touch the gear shifter, I will get the same alert that the vehicle is not in park. If the issue is not just the sensor/switch, this could mean that the transmission could potentially fall out of park and the vehicle start to roll on its own with no one inside.

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.

At around 55,000 miles my Blazer began to show error codes for “Steering Assist Reduced” and “ESC”. After 60,000 it began to intermittently populate the Check Engine Light paired with the "Steering Assist Reduced" message. Then, the engine fan would turn on high, auto-start when breaking would disable, and the steering would become more stiff. Finally, I was able to get a scan on the code and found out that it was my thermostat. After taking it to my local Chevy dealer I was quoted $1100 to repair. When I called my local mechanic I was told they could fix it for cheaper, but they were unable to find an OEM thermostat in stock which usually means there's a widespread issue with that part. Upon further research, I've found a plethora of complaints online where others with Chevy vehicles are experiencing the same issue. This causes: -Greater fuel consumption -Risk for the engine to overheat -Stiffened steering which could cause accidents

“Shift to Park”message appears when I shift to park and turn car off.

A few months ago had Blazer in for oil change. That same day check engine light came on. Was told thermostat needed to be replaced. Needed to order part. Check engine light went out then steering maybe reduced just a week ago eventually check engine light came on. Took to dealership and thermostat needed to be replaced also radiator developed a leak. Just over 60000 miles

The contact owns a 2020 Chevrolet Blazer. The contact stated that upon reaching the destination and shifting the vehicle into park, a warning message displayed reading "Please shift to Park." After, the contact observed that he was unable to switch the vehicle off. No warning lights were illuminated. The vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was 128,000.

COMMON ISSUE, The steering assist is reduced and temp gauge is stuck on C. This either a thermostat or temp sensor issue.

Shift to park message on display when car is already in park, preventing the car from turning off completely draining the battery completely.

The contact owns a 2020 Chevrolet Blazer. The contact stated while attempting to shift to park, the engine remained running, and the message "Shift to Park" was displayed. A mechanic was called to diagnose the vehicle, and the contact was informed that the transmission control, shifter harness, inline shifter wiring harness jumper, park switch, and other related components were faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 77,340.

My vehicle has been throwing an error code related to the thermostat. The temperature gauge will remain on C resulting in the fan running loudly, the air conditioner not cooling the cabin of the vehicle well, and a message displaying "steering assist is reduced drive with care". When I check the fluid levels everything is fine without issue. I'm VERY frustrated and want to get rid of my Blazer ASAP.

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.

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

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.

Questions Answered Below: What component or system failed or malfunctioned, and is it available for inspection upon request? The vehicle is at a GM Dealership now and is available for inspection. I have not authorized repairs as of yet. I am being told by the dealership: The ball joint on the control arm on the left side seized snapping the axle shaft - causing the tire to to turn out. The dealership has suggested: Mechanical repair costs $1,850, Plus an additional $2,000 due to wheel well damage caused by the failure. Has the problem been reproduced or confirmed by a dealer or independent service center? I am being told by the dealership: The ball joint on the control arm on the left side seized snapping the axle shaft - causing the tire to to turn out. How was your safety or the safety of others put at risk? Due to my slow speed turning out of the parking lot ~10 mph - the vehicle came to a sudden halt. However, had this occurred while driving any faster - it would have been very dangerous and put myself and others at significant risk. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? It was towed by AAA and has been inspected by the GM Dealership. That is the only inspection thus far. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? Earlier in the day while pulling out of a parking spot and turning the wheel to the left I thought I felt some type of resistance then it went away as I started driving. No other symptoms or warning prior to the failure.

When I parked and tried to turn off car it would continue to run. I had to put it in park and drive back to park several times before car would turn off. There’s a recall for this issue on other blazers and I feel 2020 blazers should be included. The dealer replaced the shifter assembly, cleared OTC

P0128 code- Assisted steering fault Check engine light Ac blowing cold Temp gauge flat lined Need to replace temp sensor and thermostat. Others with this issue have reported steering can completely lock up, which could cause serious accidents which could result in fatalities.

We have experienced 2 issues that are very well known issues, I will list them here. First, is the Shift to Park issue, that involves an electrical switch and wiring harness on the shifter assembly. Second, is regarding a "driver assist reduced drive with care" alert message that includes Diagnostic Trouble Code (DTC) P0128, but is actually related to either the engine cooling sensor or the cooling thermostat housing assembly. Both issues are very well known, and many owners have had these issues.

When putting the vehicle into park, we are receiving a “Shift to Park” error. This issue appears to be common among thousands of General Motors vehicles. However, the dealership is unable to assist us because the repair bulletin only applies to the 2019 model year and does not include the 2020 model year. Despite this, the issue we are experiencing is identical to the one reported for the 2019 model.

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.

I am getting the message "Shift to Park" displayed while vehicle in park after turning the vehicle off. Looking online, it seems to be a common issue with Blazers as well as other GM vehicles. I found online that "the cause of the condition may be that the park switch in the transmission control (shifter) assembly is not pulling the BCM signal low to electronically show that the vehicle is in the Park position." If this is such a common issue on similar vehicle to mine since 2018 it appears, why is this not a Recall already?!

When you shift it into park, it often doesn’t recognize that it’s in park and begins to roll backwards. This doesn’t happen every single time but at least twice a week and I have to use the parking break.