2021 Chevrolet Blazer Complaint Log

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.

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

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.

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)

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.

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.

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.

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.?

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.

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.

"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.

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

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.

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 .

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

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

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.

See attached document for complaint.

Request for Recall Review – 2021 Chevrolet Blazer Steering Assist and Cooling Fan Issue Hello, I am writing to report a recurring issue with my 2021 Chevrolet Blazer and to request that this concern be reviewed for possible recall or warranty coverage. The vehicle frequently displays an “Action Required: Steering Assist is Reduced. Drive with Care” message while driving. Additionally, after shutting off the vehicle, the engine cooling fan continues to run for up to 20 minutes, as if the vehicle is overheating. This issue has occurred multiple times and raises concerns about potential problems with the steering assist system, cooling system, or electrical sensors. I’ve noticed that other Blazer owners have reported similar experiences online, which suggests this could be a broader issue. Could you please confirm whether there are any existing recalls, technical service bulletins (TSBs), or warranty programs addressing this condition? I would also appreciate guidance on the next steps for inspection or documentation. Vehicle Information: Year/Model: 2021 Chevrolet Blazer

The contact owns a 2021 Chevrolet Blazer. The contact stated that while her husband was driving 60 MPH, the "Service Engine Soon" message was displayed. The contact's husband pulled over to the side of the road. The contact's husband used his personal FIXD machine to diagnose the vehicle. The contact’s husband retrieved DTC: P023F (Powertrain Control Module Detected a problem in the Electrical Pathway supplying power to the Fuel Pump). The vehicle was towed to an independent mechanic who diagnosed the vehicle and determined that the fuel pump had failed. The vehicle was then towed to the dealer. The vehicle has not been diagnosed. The contact related the failure to Manufacturer's Recall Number: N252516900. However, the VIN was not included. The manufacturer was not made aware of the failure. The failure mileage was 90,493.

Was informed at today's oil change that my radiator is leaking and it's something that they are seeing a bunch.

Steering assist reduced warning came on with engine light. When car turned off , radiator fan continued running for a few minutes before turning off. AC would also not work during this time. Issue has been intermittent. Was told the thermostat was getting stuck open and needs replaced.

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.

Brake booster failed after 50k miles needing repair. Brake became very still, prolonging the time it takes to stop the vehicle

my vehicle is roughly 40k miles. The temp gauge was stuck on C the cooling fan was running continuously even when the car was off and the checked engine appeared. The mechanic at the dealership said the thermostat is stuck in open position causing the computer not to know if the engine is cooling properly. For a vehicle less then 5 years old with upkept maintenance and doing a bit of research... This is a common occurrence in Chevy vehicles. Therefore, the manufacturer needs to look into recalling this issue costing people thousands of dollars. This was my first Chevy and probably my last.

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.

Auto braking system went off when I was at stop light & began to move forward (was 2nd in line of cars) and I accelerated. On the roadway, there are construction 'steel plates' laying on the ground in the area that all cars must drive over (I have driven over them in my same Blazer before) because we have no choice. One I pressed on gas & began moving over those plates, the Blazer stopped itself VERY abruptly & jerked my head forward & dash said I had to press on brake let off or something in order to move again - it was all very fast & I had a line of traffic behind me at 5:15 pm on a Friday (9/5/25). I'm very luck I did not get hit from behind & car behind me paid attention! That is the 3rd time my car has stopped suddenly; 2 times before it was when going up my very steep driveway so I had no one behind me & I wasn't as shook up - Chevy needs to REALLY look at this! It is a hazzard!!

Car wouldn’t crank

I was driving down 776 (a busy highway)Blazer completely shut off, so scary almost got hit by a semi, I don’t know how he managed to get around me , I jumped out of car! Sure thought it was my day to die! Called police for help! Had it towed home then to garage , was told it was the electrical fuel modular! Haven’t slept right in 3 days ! I’m still so shaken up!

The temperature gauge or thermostat has been replaced 3 times and continues to fail

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

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.

At routine oil change dealer noticed radiator was leaking. 60,840 miles Took it to an independent repair shop who confirmed radiator needed to be replaced. Has also seen same on other 2021 Blazers. No visible signs of leaking (fluid on garage floor) or warning indicators. No recall issued on this, however, seems to be a common problem on 2021 Blazer based on Chevy forums. Due to safety issues, vehicle is currently in shop for the needed replacement repair.

While driving my 2021 Chevrolet Blazer LT on the freeway with my wife and child, the “Brake Assist” warning came on and the brake pedal suddenly became extremely stiff. I was going about 65 mph, and it became difficult to slow down safely. We were terrified. This created a serious safety hazard, as I almost couldn’t stop in time and could have caused a crash or gotten someone killed. The check engine light came on as well. I had previously taken the vehicle in for a similar rattling or braking noise back in 2021 and was told it was “fine.” Now the issue seems to have gotten worse. I have since learned that other owners have reported similar brake assist issues on 2021 Chevrolet Blazers, and it appears there are service bulletins but no recall yet. I am extremely concerned that GM has not addressed this defect, especially since it happened without warning and endangered my family’s lives. I am requesting a full investigation into this issue and for GM to take full responsibility for the repair.

My name is [XXX] and I was a passenger in our 2021 Chevy Blazer with our young child in the back seat when the brakes suddenly failed while we were driving on the freeway. The brake pedal went stiff and wouldn’t respond. It was terrifying — we truly felt like we were going to crash. I was panicked, and my child was crying. Since then, I’ve been too afraid to drive or ride in this vehicle, even if it gets repaired. This isn’t the first issue with the car, and GM has not resolved it in a timely or helpful way. The vehicle is currently at the dealership and we are paying for a rental car out of pocket. I’m reporting this because I believe this vehicle poses a serious safety risk to families like mine. I’m asking NHTSA to please investigate this issue before someone gets hurt. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Brakes bottomed out. Message on my dash board said “Brake System Failure reduce speed to 62” and the brake went on the way to the floor.

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.

The contact owns a 2021 Chevrolet Blazer. The contact stated that while the vehicle was parked, while attempting to start the vehicle, the vehicle failed to start. The vehicle was towed to a dealer where it was diagnosed and determined that the fuel pump module needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 81,123.

The vehicle has 14,000 miles on it and the fuel pump control module has gone out on it. This happened while away from home and could’ve caused a serious situation if this had happened in a remote area where customer could’ve been stranded or if customer were pulling onto a busy road. Luckily it happened in the parking lot of a store. The vehicle was running fine on the way to the store. When customer came back out to the vehicle it cranked up but then stalled which also left customer in between parking rows, potentially causing an accident. I have the old fuel pump control module readily available for inspection. Customer had an updated version that replaced the original one that was in it. There were no signs or indications that this was going to happen until it did. I know there was a big issue / recall with the modules on Silverado and Tahoe’s etc. around the same manufacturing era. For reference- 1/2 tank of fuel, no CEL until after it happened, approx. 88° outside, coolant temp near 120°, vehicle battery had good voltage and battery cells are good

2021 Blazer Message steering assist reduced ESC needs attention 15,000 miles shoukd no way need rack n pinion . Steering reduced and is a hazard to drive

On the way to work my car said “driver assist is stopping drive with care” about 2-3 times. Upon getting out of my car it sounded like my car was still running. I turned it off and on a few times and it still sounded that way. I had to go inside or I would be late so about 20 minutes later I was able to come back and check on it and the noise stopped. It was coming from the hood. Upon googling I figured it was something to do with a faulty temperature gauge which correlated with the signal from the car as well as the sounds. It seemed like this is a very common occurrence for these cars. I called the dealership and they said they fix these everyday and the man knew exactly what was wrong before I could even finish describing it. Unfortunately I don’t know the cost of this and have already had several other things to repair in my home recently so this will be detrimental to my finances if this isn’t covered. On the way home it did it again along with no AC in the 90 degree heat and then the engine light came on. We had to open the hood and leave the garage door open to prevent any possible harm that may do in the garage. This could be very dangerous for me as I drive my car everyday to work and can’t afford to rent a car for several weeks while this one isn’t working. And I’ve only had it for 6 months. Now my husband and I have ti figure out how we are each getting to work with one car until we get this fixed or we borrow a family members car.

My 2021 Chevrolet Blazer experienced brake failure while driving, without any warning lights or diagnostic alerts from the vehicle’s onboard system prior to. This created a very dangerous situation for myself and others on the road, including my family who was in the car as well. Prior to this incident, I brought the vehicle to the dealership not long after purchasing it because I was constantly hearing screeching noises when braking. I thought it was rather soon to need new brakes, considering I purchased the vehicle brand new, but the issue was dismissed without any further inspection. This most definitely resulted in a missed opportunity to diagnose what is seemingly a more well known mechanical failure common among GM manufactured parts. After the brake failure, service technicians discovered that the vacuum pump had failed, causing the brakes to fail which led to engine damage by projecting shrapnel into the engine. This has rendered a $35,000 car purchase useless after 4 years of use without a $10,000 repair. I find this highly unethical. Upon further investigation, I learned that GM has previously acknowledged vacuum pump failures in several vehicles manufactured between 2014–2018 and even recalled certain models. The 2021 Chevy Blazer should be included in the list because failures of this part can lead to harm, injury, or loss of life. The documented defects in older GM models is consistent with my experience. I got oil changes and service regularly. The dealership should not have been so quick to dismiss the the brakes, knowing the history of these parts and the warning signs. This issue should be taken seriously as it is likely more widespread and is a ticking time bomb. Loss of life should not be the catalyst to trigger action in this situation. Other consumers are likely at risk without knowing it.

I am reporting a serious safety concern involving my 2021 Chevrolet Blazer, which experienced brake failure while driving, without any warning lights or diagnostic alerts from the vehicle’s onboard system. This created a highly dangerous situation for myself and others on the road. Prior to this incident, I brought the vehicle to the dealership after consistently hearing squealing or screeching noises when braking. The issue was dismissed and attributed to a change in federal regulations limiting the use of copper in brake pads—without any further inspection. This resulted in a missed opportunity to diagnose what appears to be a deeper mechanical failure. After the brake failure, service technicians discovered that the vacuum pump had failed, which impacted braking performance and also caused engine damage. While I’ve since learned that GM has acknowledged vacuum pump failures in several vehicles manufactured between 2014–2018 (via formal recalls), the 2021 Chevy Blazer is not currently included in those campaigns However, the symptoms and outcome I experienced are strikingly similar to the documented defects in older GM models. The lack of early diagnostic detection, coupled with dealership dismissal of clear warning signs, signals a potential emerging safety defect in this newer model that may not yet be officially recognized. Given the safety-critical nature of the braking system and the failure of both mechanical and procedural safeguards, I strongly urge NHTSA to investigate whether this issue is more widespread in recent GM models, including the 2021 Blazer. Other consumers may be at risk without knowing it.

Radiator leak, leaking antifreeze

Fuel pump module. Driving highway speeds lost all engine power as car sputtered to a stop. Luckily car srill ran enough to maintain power steering and brake function. No warning lights.Thought it was bad fuel as I had filled the tank the prior evening with little driving after that. Towed to dealership after spending 2 hours in 100 degree plus weather on the side of the highway. Dealership states it is the fuel pump module. Dealership is waiting on new unit to be installed.

The temperature sensor fails randomly. I can reset it by unplugging the battery but it will just drop off again in a week or two.

Temp stuck on cold, ac doesn’t work and driving assistance off. Fan runs after shutting engine off.

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.

Midway home I got a message on my dashboard “steering assist reduced - drive with care”, but my power steering was still functional. I parked my car in the driveway, shut it off, and the cooling fans started blowing excessively. This continued for 5-ish minutes before shutting off on its own. Then I noticed that the engine temp gauge wasn’t working. Unsure if this is a problem with the thermometer or the sensor currently.

The temp gage stays on cool. Ac does not work and the radiator fan stays on after car shuts off. Dealership finds nothing wrong.