Which parts fail
Components named in complaints (battery, alternator, wiring, ignition, instrument cluster, infotainment).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2021 Chevrolet Blazer owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2021 Chevrolet Blazer. The contact stated while driving 35 MPH, the ambient air temperature was stuck on negative forty. The contact replaced the sensor. The vehicle went into ICE/SNOW Mode on several occasions and was not driving as designed. The air conditioner was blowing out hot air. Additionally, the vehicle was pulling to the right while driving. There were no warning lights illuminated. The vehicle was taken to an independent mechanic who scanned the vehicle and determined that the sensor was operating as designed. The mechanic informed the contact that there was a loss of communication. The vehicle was taken to the local dealer, where it was diagnosed that the control arm needed to be replaced. The vehicle was repaired, but the failure recurred. The dealer informed the contact that there was no recall coverage on the vehicle. …
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.
The contact owns a 2021 Chevrolet Blazer. The contact stated that while driving 40 MPH, the vehicle stalled and was unable to be restarted. The vehicle was towed to the residence. The husband was a mechanic and discovered the 350-amp fuse failure. The fuse was replaced, and the vehicle was repaired. The dealer was not contacted. The manufacturer was made aware of the failure by phone. The failure mileage was approximately 68,400.
Odometer Fraud. The contact purchased a 2021 Chevrolet Blazer. It was discovered that there was a mileage discrepancy. The vehicle was a dealer sale. At the time of purchase, the vehicle mileage was 9,967, and at the time of registration, it was discovered that the mileage was approximately 38,000.
I went out to start my car and the light said that it was not reading the key fob because of low battery. I went and got the other key fob which had never been used and had the same result. The car was towed by Chevrolet to the dealer and it has been there for over 3 weeks. They found that it wasn't a faulty key fob but it was the receiver that gets the signal and allows the door locks to open and the engine to start. I tried moving the shift lever, stepping on the brakes, trying the remote start on the key fob and nothing would start the car nor would it lock/unlock the doors. It just kept giving me the notice that it couldn't read the key fob. I called ONSTAR and tried the actions they told me but that did not work either and they said to contact my selling dealer. ONSTAR contacted the Chevy warranty number for a tow truck but at 9PM it was too late for them to make a service call. …
I got home from work, locked my car up for the night with everything working perfectly fine, then came out to leave for work the next morning to find "update failed. Return to dealer" on the infotainment screen. I did some pretty extensive research trying to find the fix, only to find that many people are having this exact same issue in the same circumstances where their vehicle was fine when it was parked, they go to get back in and nothing with the infotainment works. According to my online research, GM/Chevy is charging anywhere from $1500-2000 to fix. I contacted few different dealers to see if I would get the same price and I absolutely did. …
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. …
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. …
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. …
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. …
Electrical complaints in other Blazer years
Frequently asked questions
How common are electrical problems on the 2021 Chevrolet Blazer?
NHTSA has 40 complaints about the electrical system of the 2021 Chevrolet Blazer, 29% of the model year's 139 complaints. The component named most often is instrument panel › speedometer/odometer (1 mentions).
Is there a recall for 2021 Chevrolet Blazer electrical problems?
No. NHTSA lists no electrical system recall for the 2021 Chevrolet Blazer, though it has 1 recall for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2021 Chevrolet Blazer electrical problems start?
Half of the complaints with a recorded mileage happened before about 38,000 miles, and 20% before 25,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.