2021 Chevrolet Blazer

While idling in my driveway, the engine started to shake and the check engine light came on. Got it diagnosed and was told by a private repair center that we had lost compression in cylinder 4 and that it was not worth the repair and we needed to replace the engine. Got it towed to the dealership, Bill Fox Chevrolet, for a 2nd opinion and they confirmed what the private shop had said. Because the vehicle was well maintained with regular preventative maintenance, it was deemed the failure was not the fault of the owner. GM extended a goodwill warranty to help cover the cost of the engine replacement (70% coverage. We were 1 month and 2,000 miles past our warranty). They never told us root cause, only that it would have cost more money to repair it than it would be to get a new engine. The Blazer had been running fine up to that point and was my wife's main mode of transportation. The Blazer only had 62,000 miles on it when the failure occured.

Incident Feb 2, 2026

All 4 tires exhibit signs of dry rot impacting the inner sidewalls of each tire. The outer layer is showing significant signs of sidewall separation. There is no sign of damage visible on the exterior side walls, if an inspection was not done on this date 08/20/26 the driver and others would have been at significant risk of injury or death due to catastrophic failure. The worst separation occurred in the front drive / steering tires. While lesser damage was visible on the rear tire the damage was also significant. The driver side rear showed the least damage with only a 2 inch separation. The other 3 tires showed 12 inches or greater separation. Images are available for review.

Incident Aug 20, 2026

The contact owns a 2021 Chevrolet Blazer. The contact stated that while driving at approximately 50 MPH, the vehicle struck a deer, causing severe damage to the vehicle's front end. The contact stated that smoke was coming from the center of the steering wheel; however, the vehicle's air bags had not deployed. The contact was transported to the local hospital and treated for chest injuries. The vehicle was towed to a local collision center. No further information was available. A Police report was filed at the scene. The cause of the failure was not yet determined. The local dealer and manufacturer were not yet contacted. The failure mileage was 52,661.

Incident Jul 29, 2026

The contact owns a 2021 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed, the accelerator pedal was depressed, and the transmission was slipping gears before the vehicle lost motive power. The contact stated that the vehicle failed to drive forward or move while in reverse. The check engine warning light was illuminated. The vehicle was towed to the residence. The contact, who was an independent mechanic, diagnosed the failure as a clutch solenoid failure. The contact stated that the transmission needed to be replaced. The vehicle was not repaired. The contact referenced an unknown recall; however, the VIN was not associated with a recall related to the failure. The dealer was made aware of the failure but provided no assistance. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 100,000.

Incident Jul 16, 2026

XXX the car had gas, turned over, but would not start. I had it towed to a repair center who towed, did diagnostics and came up with the codes for a bad fuel pump control module. It was replaced and the car starts. There was no warning. Problem was confirmed by an independent service center. All documentation is available. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Incident Jul 4, 2026

fuel pump control module failed at 26000. recall number N252516900. This is a recall that other 2021 blazers have ben part of. Over 300000 recalls so far. GM says my car isn't. Ridiculous. They dont want to acknowledge their fault. I need a formal statement that this module should be recalled for my car.

Incident Jul 4, 2026

The thermostat malfunctioned causing an error message regarding “steering assist is reduced”. When I parked and turned off, the engine fan continued to run. When car was restarted, the temp gauge inside was stuck at C. Took to dealership and they assessed. They repaired the thermostat under power train warranty, however there was a crack in the radiator (top) resulting in the need for a new radiator. This vehicle had 35,000 miles on it. Upon research online, it seems there are MANY people who have had this same issue and worse. It appears cars produced during COVID era are most affected. Chevy refused to warranty the issue. The dealership offered a small cost reduction (due to our loyalty). The thermostat and the radiator issues seem to be well known by Chevy, they just refuse to accept responsibility. Now we are out thousands of dollars on a basically “new” vehicle.

Incident May 27, 2026

The thermometer and thermometer sensor are glitching . The engine temp needle will not rise at all, the engine fan will run the whole time driving and then when it is turned off will run for 10 min . Right before this happens a notice shows the guided steering is being limited. I disconnected the battery and it reset , I drove and there were no issues , next time I started my car the engine temp needle stayed down and the van started again. This car has 36k miles on it. I just bought it 2 days before it started happening

Incident Jun 21, 2026

Lost coolant temp so replaced sensor with one from auto zone and worked for one then pegged to cold again fan runs 100% so went and bought another coolant temp sensor from Chevrolet installed that worked two pegged back to cold again fan 100% now going to pay $700.00 dollars to remove the two sensor wires for the harness all the two the Ecm heard with it being wrapped in the coil wires it gets electromagnetic static due to degradation of wires. Also Radiator started leaking after couple years but they want $3100.00 dollars for that.Was told extended warranty ran out three days before they discovered radiator leak.

Incident May 6, 2026

The vehicle showed an error on the dash which stated "Action Required Steering Assist is Reduced Drive with Care" I tool the vehicle to the dealer I purchased it from McClusky Chevy at Kings Auto Mall in Mason Ohio. They informed me that the error code is C0460:58 and GM has a service bulletin 20-NA-215 which advises to replace the Steering Gear due to internal component interference. No one explained to me that this could cause catastrophic failure and lead to a crash before I left the dealership. They could not replace it as they said they do not have the part and it is on national backorder. Additionally they told me the repair would cost me $3,400. The vehicle has 42k miles on it and this repair is not under warranty as the warranty that would have covered it expired in March of 2026. I have taken the vehicle to a different GM dealer - Tom Gill GMC in Fairfield Ohio - they are waiting on the part and I have a case opened with GM regarding the costs. You would think that if there is a risk of a catastrophic failure which could cause harm to my self or someone else - the dealer would have an obligation to tell me so before i drive off. If not legally, certainly morally.

Incident May 4, 2026

Driving on straight road going speed limit. Heard a pop behind me like a tire pop. Car fish tailed uncontrollably and ended up crashing into a Ranch Fence on the right side of the road. 2 of my kids and myself had injuries. When we got off the vehicle witnesses and I saw A rear link broken which keeps the tires straight.

Incident May 11, 2026

I am reaching out regarding an ongoing issue with my 2021 Chevrolet Blazer. The vehicle is experiencing a noticeable stutter or hesitation when shifting between second and third gear. In addition, there are instances where the vehicle accelerates unexpectedly or more aggressively than intended. This behavior is particularly concerning, as it presents a potential safety issue during normal driving conditions. These concerns have become increasingly noticeable, and I am concerned they may indicate a transmission or related mechanical problem that requires prompt inspection and resolution. Please advise if there are any known service bulletins, recalls, or warranty coverage related to these issues. For reference, the vehicle has been properly maintained and this behavior is not consistent with normal operation. Given that this is now the third major issue I’ve experienced with this vehicle, I am hoping this matter can be addressed without additional out-of-pocket expense. After additional research, I have learned that other owners have experienced the same issue. Others have stated the following: 1. Hesitation, stuttering, or jerking between gears Owners of 2020–2021 Blazers report hesitation and jerking during acceleration, sometimes described as gears “shifting in and out rapidly.” Forum users mention sluggish shifting or slipping feelings, especially at certain speeds. Others report hard or delayed shifts at low speeds (like 15–25 mph). 2. Shuddering / vibration (often tied to torque converter) There are repeated mentions of “shudder,” “surge,” or vibration during acceleration. Some cases were linked to: Contaminated transmission fluid Torque converter clutch (TCC) issues One owner said the problem felt like a bad torque converter and required service attention. 3. Unexpected acceleration / lunging Drivers across GM vehicles (including similar transmissions) report: “Jerking,” “bucking,” or “lunging” during acceleration Some describe needing to

Incident Sep 1, 2025

Went to park car in a park to drop daughter off and it sputtered out and stalled out of nowhere with no warning. I had received a lamp warning very sporadically prior to this and on occasion that stated 'reduced steering assist drive with care' this resulted in heavy steering for that drive until car was shut off and then it would go away and be fine again, fixed the car through Knudtsen Chevy due to a recall about a month before on the issue with the engine being turned off and it thinking it was still hot and still running the fan (even though the car was not running). Knudtsen fixed that issue. Low battery voltage light did not come on however battery was older so had battery installed at park to ensure the issue was not due to the battery. The oil was fresh and showed no issues, changed 2 weeks before fresh oil no issues found during service. When tried to restart the car it would think it would try to start and then sputter out and not stay in idle. Les Schwab left and called a mobile mechanic to bring the computer. Computer was hooked up and it would try to start, however, it would not know it was already running and try to start again on it's own...the codes that came up were the PO101 code came up for Mass Air Flow issue...and then the codes would go in a wild sequence of fail.....mechanic checked for loose connections around air filter, took air filter out and it was clean no issues, checked pipe no visible issues. We walked away and walked around the park to give it some time to sit and then we tried it again and it tried and sputtered out and died again would not stay idling. Then all of a sudden we heard it try to start itself without us trying to start it and it clanked. We hauled it to Knudtsen for a diagnosis. They stated "the motor will not turn this way or that way and it is seized or locked up". This is a 2021 with only 89,000 miles it should have a longer life than this. Please investigate and is there anything we can do to fix it?

Incident Apr 18, 2026

Both camshaft carriers failed due to a manufacturing defect. According to NHTSA bulletins 21-NA-240 and PIP5755, the oil leak from the cam carrier is caused by improper sealant application during manufacturing. Although the dealer addressed the issue, it was clearly not a problem that arose from normal use. The leak had the potential to worsen and lead to a fire hazard. Chevy of Montebello confirmed the issue and repaired the vehicle for over $7,500. There were no warning signs, as the leak was difficult to detect on the driveway. The low-oil warning light came on the day before we took the vehicle to the dealer.

Incident Apr 1, 2026

The transmission (powertrain) developed a delay when shifting into reverse, followed by harsh engagement. The condition worsened over time and resulted in a complete loss of reverse. The vehicle will not move when shifted into reverse. This creates a safety risk when parking, backing out of spaces, or maneuvering in traffic, as the driver cannot safely control vehicle movement. The issue occurred at approximately 89,000 miles under normal driving conditions. No warning lights were present prior to failure. The problem was reported to a dealership and diagnosed as a transmission failure. The condition is reproducible and ongoing. I was also informed that multiple vehicles of the same model were experiencing similar transmission issues at the same time. The failure limits safe operation of the vehicle and increases risk in situations where reverse movement is required.

Incident Apr 23, 2026

The contact owns a 2021 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed, there was an abnormal sound coming from the vehicle with several unknown warning lights illuminated. The contact stated that the electronic parking brake independently activated. Additionally, the failure had occurred while the vehicle was parked. The failure was persistent. The vehicle was not diagnosed or repaired by an independent mechanic or a dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 31,000.

Incident Feb 18, 2026

The vehicle had an oil leak from both the left and right camshaft carriers. The dealer confirmed the issue and carried out the necessary repairs. Because the leak was not easily detectable, it could have led to engine failure while driving. There were no warning indicators; only small oil droplets were found on the ground.

Incident Apr 7, 2026

Once I turn the vehicle off, there is a loud sound coming from the engine area that sounds like a fan. Then the first incident of the fan ongoing after the vehicle was powered off, a battery light was on the internal driver dashboard and stayed on. The battery was recently replaced during 2026 so the battery should not be anywhere near dead, dying, or needing to be checked

Incident Apr 11, 2026

The contact owns a 2021 Chevrolet Blazer. The contact stated that while attempting to start the vehicle, several unknown warning lights illuminated, and other lights inside the vehicle flashed on and off. The contact stated that the failure also occurred while driving at various speeds. A dealer was contacted. The vehicle was taken to several dealers for diagnostic tests; however, the diagnostic result was unknown. The manufacturer was notified of the failure and informed the contact that there would be a callback about the cause of the failure; however, there has been no callback yet. The approximate failure mileage was 50,000.

Incident Aug 15, 2025

My 2021 Chevy blazer Lt v6, has a service bulletin extending warranty on thermostat malfunction, that also causes the fans to run after the car is off. My vechicle was experiencing this issue, went into my local dealer, they claim thats not my issue, I need a new radiator, that has never leaked, or the car running hot. Beyond that the radiator has a service bulletin, they can fail, do to poor quality from supplier, some were replaced under warranty, some were not. This vechicle has 47000 miles, I should not be responsible for this issue. Thank you [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Incident Mar 9, 2026

Coolant smell when parked with engine running. Radiator was replaced under warranty at 16,000 miles Coolant smell again 49,000 miles. "Pressure tested at dealership with following notes: "Found radiator core on driver side seeping/leaking. provided estimate on cost. no repair made during this visit." Many forums on 2021 Chevrolet Blazer note poor quality in radiators. This would be the 3rd radiator in less than 50,000 miles on the vehicle.

Incident Jul 24, 2025

At 48,000 miles, check engine light came on and loud fan sound continued after turning car off. Took car to dealership where I was informed I needed a new radiator and it is not covered by warranty.

Incident Feb 19, 2026

This submission is an additional report related to NHTSA 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 NHTSA 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.

Incident Jan 7, 2026

The 2021 GMC Blazer (and related Chevy Blazer models) is experiencing recurring radiator failures, often requiring multiple replacements within short timeframes. The radiator was replaced in March 2024 and in early 2025 I went for an oil change and complained of smelling coolant and asked if it could be checked and was told nothing was wrong. I was told again in November 2025 that it has a leak and went to have an oil change in February 7, 2026 and was reminded that the coolant was low and the radiator needs replacing when I was first told I did not believe it to be true as it has been replaced before and I asked that it be checked and was told nothing was wrong.

Incident Feb 7, 2026

Around 55,000 miles, my 2021 Chevrolet Blazer experienced a throttle body failure. The check engine light illuminated and the vehicle entered a reduced power/limp mode condition. Throttle response was significantly limited, and the vehicle could not accelerate normally. While the vehicle remained drivable, it took substantially longer to reach speed, which could pose a safety risk when merging into traffic or crossing intersections. Diagnostic trouble code P2101 (Throttle Actuator Position Performance) was present. A Chevrolet dealer confirmed an internal throttle body failure and replaced the throttle body assembly. This component is a critical engine control system, and failure could affect acceleration and vehicle control, posing a potential safety risk. The failure occurred well before expected service life and required a costly repair. The component has been replaced and is available for inspection upon request. I believe this may represent a premature defect and should be investigated for similar failures in other vehicles.?

Incident Jan 7, 2026

Thermostat issues, gives warning steering assist decreased and then eventually check engine light, vehicle thermostat does not react/reach normal temperature, fan continues to blow after car is turned off for 5-15min, AC does not blow cool air or warm if heat turned up

Incident Dec 1, 2025

Radiator failure caused power steering assist to not function properly and insufficient vehicle heat function. Engine electric fan would run continuously after vehicle shutdown.

Incident Oct 28, 2025

For about a week and a half my car had made a high pitched wheezing/hubbing sound when started cold. This occurred at all temperatures cold and warm. Yesterday December 13th I went to run some errands and about a mile into my drive my 2021 3lt 3.6 V6 Chevrolet Blazer lost the ability to power itself. There was no electrical problem however the power train lost power all gears drive and reverse. I was able to get off the roadway without incident. I scan my check engine light and had several check engine lights including a P 0796.

Incident Dec 13, 2025

"Steering assist reduced" message was displayed. At the same time the temperature gauge stopped working and after I shut the car off, the motor fan ran full force for 10+ minutes. Shows no check engine light.

Incident Dec 3, 2025

My 2021 Chevrolet Blazer experienced a radiator failure at approximately 42,000 miles. The radiator and cooling system malfunctioned, causing coolant loss and triggering a warning light on the instrument panel. The failed radiator is available for inspection upon request. This defect put my safety and the safety of others at risk because a compromised radiator can lead to engine overheating, sudden loss of power, or even steering assist reduction while driving. These conditions increase the likelihood of an accident, particularly at highway speeds. The problem was confirmed by my Chevrolet dealer, who diagnosed the radiator as needing replacement. They initially quoted $1,800, later reducing the cost to $915.90 after acknowledging that approximately 20 customers per month at their dealership alone are experiencing the same issue. This indicates the defect is widespread, at least regionally, and may be systemic across the model. The vehicle has been inspected by the dealer service department, which is an authorized GM representative. No police or insurance inspection has occurred. Prior to the failure, a warning lamp illuminated on the instrument panel, alerting me to a cooling system issue. This was the first symptom I noticed before bringing the vehicle in for service. I believe this premature radiator failure represents a systemic defect in the 2021 Chevrolet Blazer’s cooling system. It occurred well within the 5‑year/60,000‑mile warranty period, yet the dealer claimed the radiator is not covered. I am requesting NHTSA investigate this issue, as it appears to affect many owners and poses a significant safety risk.

Incident Nov 17, 2025

Driving along vehicle shut down in middle of road replace fuel pump, fuel module control in August 2025. Now both top and bottom fuel hose needs replacing. On Nov 2025 I smelled gas and vehicle shut down

Incident Aug 20, 2025

In September 2023, when getting my vehicle serviced for a routine oil change, I was told there was a leak in my radiator. They replaced the entire thing under warranty. On November 15th, 2025, while driving on the highway heading home from out of town with my children, an error flashed up saying “steering assist is reduced – drive with care” Upon arriving home, the fan on my car was running on high for a solid 10 minutes after turning the car off. No recall but Special Coverage N252508350 covers the thermostat replacement. Upon inspection by a mechanic, I was informed that the radiator is also leaking again in the exact same spot as it was previously. It should be noted I have never seen leaking fluid in my garage/driveway. I’ve driven less than 10,000 miles since the radiator was replaced previously. If there is a known problem with the coolant system which can cause overheating and steering assist issues, why isn't the faulty radiator and thermostat recalled. The radiator is cased in plastic to aluminum. Plastic can easily catch fire if a car overheats. The casing also prevents an owner from even knowing if there is a leak since the plastic is catching leaks - the mechanic informed me that's why I didn't know about both times it leaked. This is a 4yr old car with 46k miles, twice replaced radiator and thermostat. A recall should be issued since both problems could potentially cause a fire from an overheated engine & loss of steering assist while driving. A google search quickly showed me thousands of other Chevy Blazers from 2019-2021 with reoccurring thermostat and radiator issues. I feel unsafe driving in my vehicle but still owe too much to even trade it in for something else. I've owned dozens of vehicles in my lifetime, used and new and keep them 8-10yrs and have never had to replace a thermostat and radiator. This vehicle is dangerous due to GM/Chevy's cheap radiator model and thermostat which could overheat and catch fire

Incident Nov 15, 2025

The contact owned a 2021 Chevrolet Blazer. The contact stated that while driving at 30 MPH, a 2012 Mazda CX-7, allegedly going at 70 MPH traveled through an intersection and crashed into her vehicle. The Mazda later crashed into another unknown vehicle. All the air bags deployed; however, the driver's side air bag exploded in her face. The air bag dust was in the vehicle. The contact was rendered unconscious due to the incident. All the warning lights illuminated after the crash. OnStar was activated and disabled the vehicle. There were unknown fluids leaking from the vehicle. There was no reported fire. A police report was filed. The contact sustained a severe brain injury, and medical attention was provided at the hospital. The vehicle was towed to her residence. The insurance company later towed the vehicle on a flatbed to a tow lot. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not notified. The vehicle was deemed a total loss by the insurance agency. The failure mileage was approximately 36,463.

Incident May 23, 2025

Car was running fine yesterday, today does not want to start. Thought it was the battery, bought anew battery. Still wouldn't start. Rest of cat is getting great power. Code reader is reading its a fuel pump control moduler which just so happens to be in an open recall for my exact year of vehicle yet my vin number does not pop up on the GMC website under active recall. I have a 2021 chevy blazer .

Incident Nov 16, 2025

Action Required "Steering Assist Warning" drive with caution, Temp gage reads cold, A/C stops working, engine cooling fan runs on high speed (even after the engine is shut off), pending P2018 code, with no Check Engine Light (CEL). Replaced Engine coolant Temperature (ECT) sensor, problem did not go away. Several reviews suggest to replace the thermostat, check fuses for proper insertion, reroute ECT wiring, and possibly replace radiator. Most of these repairs can be very expensive. Chevy Blazer Forum states that the issue is a out of range detection of ECT sensor reading. GM needs to determine a true solution and stop guessing at owner expense/frustration.

Incident Sep 18, 2025

See attached document for complaint.

Incident Oct 14, 2025

I was driving at approx 45 mph when my car lost all ability to accelerate and shut down in the street. Flashing check engine light and esc warning on the screen. It would try to start but wouldn't. I had it towed to a mechanic who diagnosed and informed me that it is the Fuel pump power control module. Upon review he I formed me that there was a recall posted in September 2025 for 2021 Blazer on this exact issue. My car has now been unusable for a week as my mechanic recommends it be repaired via recall at dealership.

Incident Oct 17, 2025

I PURCHASED MY 21 CHEVY BLAZER IN 2024 AND HAD A FEW PROBLEMS WITH A TRANSMISSION PROBLEM. THE VEHICLE WOULD STOP AND JERK WHENEVER I DROVE IT. I TOOK IT TO THE DEALER A FEW TIMES FOR REPAIR. THEY CLAIMED TO HAVE FIXED THE PROBLEM, BUT IT STARTED AGAIN SEVERAL MONTHS LATER. THE VEHICLE HAS APPROX 82,000 MILES ON IT. I HEARD THAT THERE WERE SOME RECALLS ON THESE VEHICLES, BUT NOT SURE IF MINE IS ONE OF THEM. I FEEL THERE ARE OTHER VEHICLE LIKE MINE THAT HAVE THE SAME PROBLEM.

Incident Sep 10, 2025

Car wouldn’t crank

Incident Sep 1, 2025

In March after a short drive, 24 miles, the car temp was pegged at Cold. After turning off the car, the fan continued to run several minutes. After a quick internet search several posts commented on a similar issue with their vehicle. Two potential issues were identified - thermostat failure or programming issue. With less than 40,000 miles on the car, I purchased a diagnostic tool. Running the tool program two errors were identified. After resetting the sensors, the problem went away. In September, yesterday and today the problem occurred again - and the error reset fixes the issue. I believe Chevy needs to fix the issue with a recall to either update programming or replace the thermostat. [Several posts state the thermostat replacement didn't fix the issue and is very expensive.]

Incident Mar 15, 2025