AI Damage2021 Chevrolet Blazer: common problems
Owners of the 2021 Chevrolet Blazer filed 140 complaints with NHTSA, most often about engine and electrical system. The maker issued 813 service bulletins for this year. Details by component below, with sources.
Key figures
- Owner complaints
- 140
- involving a crash
- 6
- Technical service bulletins (TSB)
- 813
What fails most often
- 1 Engine 30% of all complaints
- 2 Electrical system 29% of all complaints
- 3 Service brakes 14% of all complaints
- 4 Powertrain 14% of all complaints
- 5 Fuel/propulsion system 12% of all complaints
- 6 Steering 11% of all complaints
- 7 Forward collision avoidance 6% of all complaints
- 8 Tires 4% of all complaints
- Engine: 42 complaints (30% of all); manufacturer bulletins for this component: 87.
- Electrical system: 40 complaints (29% of all); manufacturer bulletins for this component: 187.
- Service brakes: 20 complaints (14% of all); manufacturer bulletins for this component: 32.
- Powertrain: 19 complaints (14% of all); manufacturer bulletins for this component: 92.
- Fuel/propulsion system: 17 complaints (12% of all), 1 of them with a crash reported by the owner; manufacturer bulletins for this component: 18.
Engines and transmissions
US-market versions per EPA. On the right: how many NHTSA complaints name this engine or transmission type.
- 2 L · petrol · turbo · 4 cyl
- 2.5 L · petrol · 4 cylnamed in 1 complaints
- 3.6 L · petrol · 6 cylnamed in 1 complaints
- automatic, 9-speed
Drive: FWD, AWD
Symptoms owners describe
How many of the 140 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Engine | 42 | 0 | 87 |
| Electrical system | 40 | 0 | 187 |
| Service brakes | 20 | 0 | 32 |
| Powertrain | 19 | 0 | 92 |
| Fuel/propulsion system | 17 | 1 | 18 |
| Steering | 15 | 1 | 17 |
| Forward collision avoidance | 8 | 1 | 9 |
| Tires | 5 | 0 | 16 |
| Suspension | 4 | 2 | 17 |
| Engine and cooling | 3 | 0 | 135 |
| Lane departure | 3 | 0 | 5 |
| Wheels | 2 | 0 | 36 |
| Structure | 2 | 0 | 33 |
| Air bags | 2 | 2 | 11 |
What owners report
Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.
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.
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.
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.
There was no warning light illuminated. The contact stated that the vehicle hit the median and bounced, facing incoming traffic. The contact slammed on the brakes and shifted into park (P). The air bags deployed. The contact was able to exit the vehicle with the assistance of bystanders.
I called the service department the next day, Saturday April 29, and was told that the problem was the fuel pump control module, which was under warranty, and it could be 3 months before it was fixed as they didn’t have one, and there was a large backorder.
When it did stall out, and we made it to the curb, it shut itself off. That was yesterday then this morning it started to do it a little bit when we left the house.
Upon opening the hood, the contact noticed gray smoke under the hood. The contact's minor child was occupying the vehicle during the failure. The vehicle was taken to an independent mechanic, where the contact was informed that the AC compressor had melted, requiring replacement of the AC kit and expansion valves.
The main instrument cluster where the speedometer and fuel gauge etc etc reside went blank during operation of the vehicle. I wasn't able to pull over safely until my destination was reached. Restarting the car seemed to "solve" the issue.
When owners complained
NHTSA complaints by filing year. The peak shows at what age the problems show up most.
Comparison
By complaint count this model year ranks 452 of 2,102 model years in the NHTSA data (top 22% most complained about).
On average one model year of the Blazer has 92 complaints (8 years in the data). This year has 140, above average.
What to check before buying
- Engine. Cold start, unusual noises, oil leaks and engine codes.
- Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
- Service brakes. Pedal feel, ABS operation, leaks, discs and hoses.
- Powertrain. Shift quality under load, harsh shifts, transmission codes, CV joints.
Manufacturer service bulletins
Bulletin titles as filed with NHTSA.
- This PI provides Diagnostics tips on how the LIN bus works and how to diagnosis it
- This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance
- This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues
- PI to help diagnose A/C concern
- This Preliminary information communicates an issue with an OTA pending message still displayed after an…
This Preliminary information communicates an issue with an OTA pending message still displayed after an OTA event and how to reset/clear the message.
- Pi created to provide GM dealers with information on gathering information for projection issue
- This preliminary information communicates information about how to determine if a wheel and tires size…
- Improvements to OnStar functionality
- This Preliminary information communicates the steps on how to save a GDS2 Session Log and upload to a…
This Preliminary information communicates the steps on how to save a GDS2 Session Log and upload to a Technical Assistance Case in CX Connect.
- This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic…
This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC'ss
- Improvements to OnStar functionality
During the update process, your radio may stay on up to 5 minutes after you exit the vehicle. This is expected behavior when an update package is onboard the vehicle. Do not service your vehicle during installation.
- Emission Recall
General Motors has decided to conduct a Voluntary Emission Recall. Certain vehicles listed above may have a condition which can cause the fuel pump power control module to fail. If this were to occur, fuel flow to the…
NHTSA lists 813 bulletins for this year; the 12 newest are shown here.
Other years of this model
Questions and answers
What are the most common problems with the 2021 Chevrolet Blazer?
Owner complaints to NHTSA most often mention: engine, electrical system, service brakes. Total complaints: 140. The most frequent symptoms in complaint texts: warning lights, check engine (29%), A/C or heater (9%), fuel system, fuel smell (9%).
How many service bulletins (TSB) were issued for the 2021 Chevrolet Blazer?
NHTSA lists 813 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.
Should I buy a 2021 Chevrolet Blazer from a US auction?
Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.
Other 2021 models
Read also
Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-04.