Owner-reported complaints naming the driver-assistance system, filed with NHTSA
Data refreshed
Driver assistance reportsComplaints are reports submitted to NHTSA by owners and drivers. NHTSA does not verify most reports before publishing them, and a complaint does not establish that a defect exists. Volume is influenced by how many of a vehicle were sold, how long it has been on the road, and how much attention an issue has received.
10
Latest Jun 22, 2026
Share of all reportsThis category as a share of every owner report on file for this model year. One report can name more than one component, so the categories overlap.
8%
of 125 total
Crash or fire reportedReports in this category whose submitter recorded that a crash or a fire occurred. The reporter's own answer on the NHTSA form, not a verified finding.
1
Injuries or deaths reportedTotals the submitters entered on their own reports in this category. Not verified by NHTSA and not a casualty statistic.
1
What this page shows
Reports naming forward-collision avoidance, lane keeping, back-over prevention, cruise control and related electronic driver-assistance systems. Every record below is an owner-reported complaint about the 2021 Chevrolet Blazer submitted to NHTSA — not a confirmed defect, not a recall and not a manufacturer bulletin. 10 reports on file name it.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Owner reports naming driver-assistance
Shown in the owner’s own words, exactly as filed
Driver assistanceElectricalEngine
Filed Jun 22, 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
NHTSA ID
11745573
Incident
Jun 21, 2026
Driver assistanceEnginePowertrain (other)
Filed Dec 15, 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.
NHTSA ID
11705228
Incident
Dec 13, 2025
Driver assistance
Filed Sep 9, 2025
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!!
NHTSA ID
11685984
Incident
Sep 5, 2025
BrakesDriver assistance
Filed Jul 24, 2025
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.
NHTSA ID
11675890
Incident
Jul 24, 2025
Driver assistanceEngineSuspension
Filed Jul 21, 2025
The first incident started on 08/16/2024, 2 days after buying the vehicle used from Dealership. I started getting notifications stating "Service-Front Camera not available" and sure enough, I no longer had a front camera, which then means I no longer have front collision alerts. Then I started getting the random notifications to drive carefully because drivers assistance has been reduced, and now my vehicle's fan will randomly run for up to 30 minutes after it has been shut off and even after a less than 2 mile drive to gas station and back home, it does this. Last item is the vehicle pulls to the right, and I have not hit anything nor has it ever been in an accident prior to my purchase, and my brakes squeal horribly, which shouldn't be happening condidering I haven't even driven the vehicle 5,000 miles in the year since I bought it !
NHTSA ID
11675087
Incident
Aug 16, 2024
Driver assistanceEngine
Filed May 3, 2025
"Driver Assisted Reduced Use Drive With Care Message" comes on when it is over 70 degrees outside. The temperature gage reads zero, A/C does not work, when the car is turned off the fan runs on high for an extended period of time. Showing code P0128 Used car purchase, came on 3 days after receiving vehicle from the dealership. Reset the code came on again 2.5 weeks later (5/3/2025) when the outside temperature was in the 70's
NHTSA ID
11658644
Incident
Apr 13, 2025
BrakesDriver assistance
Filed Jan 29, 2024
I have made numerous complaints to Jeff Schmitt Chevy dealership Dayton, Ohio regarding parking brake being engaged upon starting vehicle even though vehicle is on flat surface. Twice now, last occurring [XXX], while gradually increasing speed to make a left hand turn the vehicle suddenly self-brakes, during acceleration, making a harsh screeching sound. I remove my foot completely from the accelerator before I accelerate again. The initial incident was reported to chevy dealership. No findings have been noted per dealership. No accidents have occurred. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA ID
11568424
Incident
Jan 29, 2024
Driver assistanceSuspension
Filed Aug 17, 2023
Crash reported1 injury reported
The Esc display came up then sutbality sensor show and my back wheel went right. My car flipped twice and then landed on the guardrail.
NHTSA ID
11539221
Incident
Aug 16, 2023
Driver assistance
Filed Jun 30, 2023
The radio and all the sound notifications such as turn signals, emergency flashers, crash avoidance, cross traffic, lane departure, and the use of the emergency OnStar system do not work. this has been addressed in GM service information #PIT5971B: Loss OF Audio and OnStar LED is Red - (Apr 3, 2023) GM appears to be addressing this as an inconvenience of not having the entertainment of the radio and not the safety features associated with it. This also includes the use of hands-free cell phone.
NHTSA ID
11529702
Incident
Jun 6, 2023
Driver assistanceOther / unspecified
Filed Jul 6, 2021
The contact owns a 2021 Chevrolet Blazer. The contact stated that while stopped at a railroad track, the vehicle independently stopped and went into crash mode while on the railroad tracks upon acceleration. The contact shifted the vehicle into reverse and then into park. Once the vehicle was placed into drive, the vehicle resumed normal operation. The vehicle was taken to a dealer where they replaced an unknown module and performed a software update. Despite the repair, the contact stated that the failure persisted. The contact also stated that while driving at 40 mph, the traction control warning light illuminated on the instrument panel as the steering power was reduced. The contact took the vehicle back to the same dealer and the mechanic replaced the rear differential, clutch, and control module. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 4,400
NHTSA ID
11423591
Incident
Apr 27, 2021
Mileage
4,400 mi
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Other components reported on this vehicle
Categories with enough reports to have a page of their own