general problems of the 2020 Chevrolet Blazer - part 1

62 problems related to power train have been reported for the 2020 Chevrolet Blazer. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2020 Chevrolet Blazer based on all problems reported for the 2020 Blazer.

1 Power Train problem

Failure Date: 03/16/2026

Just took my car to the chevy dealership today and had them go over the car because I keep getting the message steering assist has been reduced and the fan is constantly running at the highest speed and it also makes it where I can not use the a/c or heat in the car! I don’t know the code off hand but it has something to do with the cam shaft and the thermostat for the antifreeze! from what chevy told me today it is a $9000 job to tear down the left side of the engine because the camshaft carrier gasket is leaking oil! which is probably why that code is popping up. Or from what I was told today it could be from the battery which I believe they were trying to shift blame. Either way this camshaft stuff really needs to be investigated!!.

2 Power Train problem

Failure Date: 02/18/2026

The contact owns a 2020 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed with vvt sensor failure. The sensors were replaced; however, the failure recurred. The vehicle was taken back to the mechanic, where a solenoid was replaced. The vehicle was repaired. The contact was informed that if the failure recurred, there might be an internal engine failure. The dealer was not contacted. The manufacturer was notified of the failure and referred the contact to the NHTSA hotline to report the failure. The failure mileage was approximately 70,000.

3 Power Train problem

Failure Date: 12/11/2025

The contact owns a 2020 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed, the vehicle hesitated with a grinding sound coming from the vehicle, with the check engine warning light illuminated. The contact stated that the vehicle was jerking while driving and while accelerating from a stop. In addition, the contact noticed fuel leaking from the front end of the vehicle while the vehicle was parked at the residence. The vehicle was taken to the dealer, where it was diagnosed that the start/stop accumulator end cap had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA hotline for assistance. The approximate failure mileage was 157,236.

4 Power Train problem

Failure Date: 11/13/2025

Steering assist reduced message followed by check engine light came on and temperature gauge not moving from cold. Immediately took it to the dealership hiley Chevrolet in rockwall, TX. After $250 for diagnostic, failed thermostat is the cause and $1216 repair cost. Known issue that Chevrolet issued special coverage for 2021 Blazers, but none for 2020. My vehicle has a little more than 51,970 miles. Same vehicle just had battery replaced two weeks ago at same dealership and no other issues showed up during diagnostic then.

5 Power Train problem

Failure Date: 10/09/2025

I backed my vehicle out of the garage and put it in park and stepped out of the driver's door. I was going to put my son in his car seat in the rear seat when the vehicle started moving backwards and the opened driver's door knocked us down. I was able to push my son out of the way, but the vehicle continued and the front left tire rolled over both of my legs. The vehicle continued in reverse along the driveway, struck a trash container and went up the incline at the main road. It crossed a busy two lane road and into my neighbors yard. The vehicle came to a stop about 10 feet from our neighbor's house without striking anything else. We purchased this car used with just under 300 mile on it. During the time that we've owned it, it has randomly flashed a "shift to park" warning lamp on the dash when I shift it to park and turn it off. It has never done what happened to me today. A few months ago, my husband and I took the car to the gm dealership to have it checked out before the warranty expired. We told them about the "shift to park" warning lamp and that the car was shifting hard while driving it. They kept the car a few days and told us they were unable to find anything wrong with it.

6 Power Train problem

Failure Date: 09/03/2025

My vehicle lost complete power while I was sitting at red light. The dashboard went completely out and pop back on stating to put the vehicle in park and push the brake to start. After following those instructions the vehicle failed to start and I left disability until onstar notified mpd to assist. While waiting for assistance I was almost hit 3 times. When mpd arrived on the scene they were able to push the vehicle out of traffic. After my vehicle arrived at the shop I was told the power failure was caused by the malfunction of the DC/DC converter output voltage. I see a bulletin was put out but a recall was my made available. I feel this is a major issue due to the vehicle losing power.

7 Power Train problem

Failure Date: 06/26/2025

The contact owns a 2020 Chevrolet Blazer. The contact stated that while his wife was driving 80 mph, the vehicle failed to accelerate as intended while depressing the accelerator pedal. In addition, the contact stated an abnormal sound could be heard coming from the engine. The vehicle stalled and the contact's wife was unable to move to the side of the road. The message "shift to neutral and press the start button" was displayed. The police assisted with traffic control while the vehicle was pushed to the side of the road. The vehicle failed to start. The contact stated that prior to the most recent failure, the gear shifter would be stuck in park(p). The contact would move the gear shifter several times to cause it to move. The contact stated that the failure recurred several times, and the vehicle responded as needed after several attempts. After several attempts, the check engine light was illuminated. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure and referred the contact to the nhsta hotline for assistance. The approximate failure mileage was approximately 40,000.

8 Power Train problem

Failure Date: 06/23/2025

The contact owns a 2020 Chevrolet Blazer. The contact stated that while parking the vehicle and shifting to park(p), the message "shift to park” was displayed. The contact turned off and restarted the vehicle several times and shifted from drive(d) to park(p) several times before the message disappeared. The contact stated that the vehicle was also showing electrical failures. The contact stated that after shifting to park(p) and turning off the vehicle, the contact heard chimes as if the vehicle was still running. There was no warning light illuminated. The contact stated that one morning the vehicle had to be jumpstarted and on another morning the battery was completely drained. The battery was taken to an auto parts store to be checked. The contact was informed that the battery was in good operating condition. The contact stated that the battery was drained again and was replaced. The contact had not taken the vehicle to a local dealer or independent mechanic to be diagnosed or repaired. The manufacturer was informed of the failure and referred the contact to the NHTSA hotline for assistance. The failure mileage was approximately 40,000.

9 Power Train problem

Failure Date: 06/02/2025

I am experiencing the well known "shift to park message" while the shifter is in park. I cannot turn the vehicle off and I am worried the battery will die. This is a well documented issue with this vehicle, and several other models outlined in TSB 19-na-206, for years and yet they refuse to issue a recall to repair the faulty design or component . I have reached out to them via email, but no action has been taken, see email below. ------------------------------------------------------------------------------------- gm customer care, I am writing to request assistance regarding an issue with my 2020 chevy Blazer VIN# [xxx] . This is my fourth new gm vehicle, and while it is currently outside the 36-month warranty period, the vehicle has only 18,800 miles on it. Recently, the vehicle began displaying a persistent "shift to park" message on the driver information center, despite the gearshift being in the park position. As a result, the vehicle remains in the on position and cannot be turned off. This is a well-documented issue affecting several gm models, including the Blazer, acadia, malibu, traverse, and volt. For reference, please see TSB 19-na-206 attached. Repair costs for this issue appear to vary widely, sometimes exceeding $1,000 depending on location and dealership. Given that this appears to be a known design or component issue, I do not believe this should be an out-of-pocket expense for the customer. As a long-time gm customer, I respectfully request that gm cover the cost of this repair. I am disappointed that there has been no proactive recall or service campaign, especially considering the volume of customer complaints reported online. Thank you for your time and attention. I look forward to your response and hope gm will stand behind its products in this matter. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

10 Power Train problem

Failure Date: 06/02/2025

The contact owns a 2020 Chevrolet Blazer. The contact stated upon shifting to park(p) and attempting to turn off the vehicle, the message that the transmission was not in park(p) was displayed. The contact stated that the failure recurred several times, and the vehicle responded as needed after several attempts. The dealer was not notified of the failure. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure, but no assistance was provided. The failure mileage was approximately 38,000.

11 Power Train problem

Failure Date: 05/21/2025

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.

12 Power Train problem

Failure Date: 05/16/2025

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.

13 Power Train problem

Failure Date: 05/02/2025

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.

14 Power Train problem

Failure Date: 04/24/2025

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. . Read more...

15 Power Train problem

Failure Date: 04/19/2025

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

16 Power Train problem

Failure Date: 04/14/2025

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.

17 Power Train problem

Failure Date: 04/01/2025

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.

18 Power Train problem

Failure Date: 03/29/2025

Check engine light came on, gave error code p0128.

19 Power Train problem

Failure Date: 03/17/2025

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

20 Power Train problem

Failure Date: 03/10/2025

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.

21 Power Train problem

Failure Date: 03/08/2025

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!!.

22 Power Train problem

Failure Date: 03/01/2025

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.

23 Power Train problem

Failure Date: 02/10/2025

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.

24 Power Train problem

Failure Date: 01/31/2025

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.

25 Power Train problem

Failure Date: 12/26/2024

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.

26 Power Train problem

Failure Date: 12/12/2024

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.

27 Power Train problem

Failure Date: 11/21/2024

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.

28 Power Train problem

Failure Date: 11/14/2024

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.

29 Power Train problem

Failure Date: 11/02/2024

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?!.

30 Power Train problem

Failure Date: 10/28/2024

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.

31 Power Train problem

Failure Date: 10/20/2024

The contact owns a 2020 Chevrolet Blazer. The contact stated that the transmission was slipping while driving in the lower gears. The contact stated that the message “reduced steering - drive with caution” was displayed. The vehicle was taken to the dealer but was not diagnosed or repaired. The contact stated that the failure persisted, and the vehicle became inoperable. The manufacturer was informed of the failure and opened a case. The failure mileage was approximately 50,000.

32 Power Train problem

Failure Date: 09/24/2024

2020 chevy Blazer - shift to park while gear is already in park: while putting the gear in park, the warning chime to shift it into park is initiated. It has happened 3 to 4 times in the past three days. I took the vehicle to the local chevy dealership. The service team/dept. Diagnosed that the transmission shifter unit assembly must be replaced. The 2019 chevy Blazer had these issues which prompted a TSB/recall however it wasn't extended to the 2020-year models and chevy dealership refused to include it as a warranted repair which just passed 44,000 miles. This is a safety issue, and it should be replaced without additional cost to customer as this issue was already identified as a safety concern in 2019, however chevy does not want to identify the issue as a covered repair per the manufactures warranty.

33 Power Train problem

Failure Date: 09/11/2024

2020 chevy Blazer- bad transmission at 130,000 miles.

34 Power Train problem

Failure Date: 09/10/2024

The contact owns a 2020 Chevrolet Blazer. The contact stated that upon arriving to his destination, the vehicle failed to detect that the gear shifter was in park(p), preventing the vehicle from being turned off. The contact stated that the message "please shift to park" was displayed. There were no warning lights illuminated. The vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 50,000.

35 Power Train problem

Failure Date: 09/01/2024

Component/system involved: the shift-to-park sensor in my 2020 chevy Blazer is malfunctioning. After shifting into park, the vehicle does not detect it and displays a “shift to park” message. The issue is ongoing, and the component is available for inspection if needed. Safety risk: the vehicle cannot be fully shut off or locked, increasing the risk of battery drain or unintended movement. This poses a safety risk if the vehicle is left in public or on an incline. Inspection history: the vehicle has not been inspected warning signs: the “shift to park” message appears when trying to turn off the vehicle, despite the gear being in park. This started around fall 2024 and has occurred regularly since.


Other Power Train related problems of the 2020 Chevrolet Blazer


Blazer Service Bulletins
Blazer Safety Recalls
Blazer Defect Investigations