2021 Chevrolet Blazer problems & reliability
133 owner complaints filed with NHTSA for the 2021 Chevrolet Blazer, alongside 1 safety recall campaign. Last verified Sep 22, 2026. Complaints are unverified reports submitted by owners to the federal Office of Defects Investigation.
Each complaint is counted once (by NHTSA case number), even when it names several components.
5 complaints report injuries (7 injured).
Federal crash records (FARS 2020–2023): 2021 Chevrolet Blazer vehicles were involved in 27 fatal crashes with 4 occupant deaths. Involvement counts are not adjusted for how many are on the road and do not imply fault or a vehicle defect.
Most reported problems
| Component | Complaints | Share |
|---|---|---|
| Engine → | 41 | 31% |
| Electrical System → | 38 | 29% |
| Unknown / Other | 20 | 15% |
| Service Brakes → | 19 | 14% |
| Power Train → | 18 | 14% |
| Fuel/propulsion System → | 17 | 13% |
| Steering → | 15 | 11% |
| Forward Collision Avoidance | 7 | 5% |
| Tires | 5 | 4% |
| Suspension | 4 | 3% |
Component groups as classified by NHTSA. A complaint can name more than one component, so shares may sum to more than 100%.
All 23 reported components →Common symptoms owners describe
Keyword analysis of complaint narratives; one complaint can describe several symptoms.
Mileage when problems occurred
Among the 22 complaints that included a usable odometer reading, the median reported incident mileage was 37,232 miles (middle 50% between 25,000 and 67,050 miles).
Complaints by incident year
What owners report
“Vehicle Information: 2021 Chevrolet Blazer 2.5L engine, VIN [XXX]. Odometer 118000 miles.Description of Incident: While operating the vehicle, the mechanical brake vacuum pump experienced a catastrophic internal failure. The drive gear housing shattered violently without warning, shearing off the end of the connecting…”
Engine · filed Sep 17, 2026
“My 2021 Chevrolet Blazer has experienced repeated problems involving the cooling system and is now exhibiting recurring symptoms that concern me about the vehicle’s reliability and safety. In 2023, the vehicle required a radiator/cooling-system repair. In 2024, it again required radiator/cooling-system repair, which…”
Wheels · filed Sep 16, 2026
“The contact owns a 2021 Chevrolet Blazer. The contact stated that a technician identified a radiator leak during an emissions test after smelling an abnormal coolant odor. The technician confirmed that the coolant had leaked from the vehicle. Prior to the discovery by the technician, the contact’s husband observed…”
Engine and Engine Cooling · filed Sep 9, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Technical service bulletins
813 manufacturer communications (TSBs, service campaigns, warranty extensions) are on file with NHTSA for the 2021 Chevrolet Blazer. The 10 most recent:
This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
PIP4902W · Service Bulletin/Repair Instructions · issued Sep 4, 2026
This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues
PIC6551C · Service Bulletin/Repair Instructions · issued Aug 20, 2026
PI to help diagnose A/C concern
PIT5099J · Service Bulletin/Repair Instructions · issued Jul 21, 2026
This Preliminary information communicates an issue with an OTA pending message still displayed after an OTA event and how to reset/clear the message.
PIT5966F · Service Bulletin/Repair Instructions · issued Jun 23, 2026
Pi created to provide GM dealers with information on gathering information for projection issue
PIC6423A · Service Bulletin/Repair Instructions · issued May 11, 2026
This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues
PIC6551B · Service Bulletin/Repair Instructions · issued May 11, 2026
This preliminary information communicates information about how to determine if a wheel and tires size change is available.
PIT3271Q · Service Bulletin/Repair Instructions · issued Apr 1, 2026
Improvements to OnStar functionality.
N25-250552 · Over The Air · issued Mar 21, 2026
This Preliminary information communicates the steps on how to save a GDS2 Session Log and upload to a Technical Assistance Case in CX Connect.
PIP6104 · Service Bulletin/Repair Instructions · issued Mar 9, 2026
This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
PIP4902V · Service Bulletin/Repair Instructions · issued Mar 9, 2026
TSBs are repair guidance manufacturers send to dealers — they are not recalls and repairs are not automatically free. Full documents are available on NHTSA’s site.
Safety recalls
The 2021 Chevrolet Blazer has 1 NHTSA recall campaign — recall repairs are free at franchised dealers regardless of the vehicle’s age.
Check whether your specific vehicle is affected
Recall campaigns often cover only certain VIN ranges. Enter your VIN on the official NHTSA site to confirm whether your vehicle is included and whether the repair is still open.
Check VIN on NHTSA →Buying a used 2021 Chevrolet Blazer?
- · Decode the seller’s VIN with our free VIN decoder to confirm the exact year, engine and trim.
- · Check for unrepaired recalls by VIN on NHTSA’s official lookup — recall repairs are free.
- · Among complaints with usable mileage, the median reported incident mileage was 37,232 miles. This does not predict when a particular vehicle will develop a problem.