2021 Chevrolet Blazer Recalls, Issues & Maintenance

The 2021 Chevrolet Blazer carries 1 open NHTSA recall — most recently covering seat belts. Owners report 7 recurring issue clusters, led by “Thermostat / ECT sensor failure with post-shutdown fan run-on.” Chevrolet vehicles use the GM Oil Life System (OLS) — a percentage-based monitor that calculates oil life from driving conditions, not fixed mileage. When the OLS drops to 0%, oil and filter are due. The schedule below reflects GM's Normal Use intervals for everything else.

1 Open Recall

Source: NHTSA

SEAT BELTS

Campaign #20V811000 · Dec 23, 2020

Issue: General Motors, LLC (GM) is recalling certain 2020 Chevrolet Bolt EV and 2021 GMC Canyon and Sierra 1500, 2500 and 3500, Yukon, Yukon XL, Cadillac Escalade and Escalade ESV and Chevrolet Blazer, Camaro, Colorado, Equinox, Silverado 1500, 2500 and 3500, Suburban and Tahoe vehicles. Incorrect bolts may have been used at one or more fastening locations to secure the seat belts to the vehicle. If an incorrect bolt was used, the seat belt may not be properly attached to the vehicle.

Risk: If a seat belt assembly is not properly attached to the vehicle, the seat belt may not properly restrain an occupant in the event of a crash, increasing the risk of injury.

Fix: GM will notify owners, and dealers will replace the suspect bolts, free of charge. The recall began January 29, 2021. Owners may contact GMC customer service at 1-800-462-8785, Cadillac customer service at 1-800-458-8006, or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N202322230.

Recall data refreshed Sep 6, 2026.

Known issues for this vehicle

What drivers and federal regulators have officially reported about the 2021 Chevrolet Blazer.

Reported to NHTSA

Thermostat / ECT sensor failure with post-shutdown fan run-on

ENGINE AND ENGINE COOLING, ENGINE AND ENGINE COOLING:COOLING SYSTEM:FAN

28 NHTSA complaints · 2024-10-17 → 2026-07-21

"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
Owner report, NHTSA ODI #11703920
P0128, AC not working, Steering Assist Reduced, and Temp Gauge not working. Problem caused by faulty ECT wiring. First the problem is the ECT is a two wire (signal + and -) 26 gauge wire running through the ignition coil wire harness
Owner report, NHTSA ODI #11627479
The contact stated that upon turning off the vehicle, the fan remained engaged for approximately 10 minutes. Additionally, the contact stated that the A/C system was intermittently inoperable. The contact stated while driving at an…
Owner report, NHTSA ODI #11646473

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Fuel pump control module failure causing stall

FUEL/PROPULSION SYSTEM

14 NHTSA complaints · 2022-02-19 → 2026-07-09

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…
Owner report, NHTSA ODI #11684653
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…
Owner report, NHTSA ODI #11670138
I went to restart the vehicle to leave and I noticed the check engine light on. Since the vehicle seemed to be driving okay I thought I could make it home and check the car's computer to see what the issue was. As I was leaving the parking lot I…
Owner report, NHTSA ODI #11631586

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Transmission slipping, loss of gear, and complete failure

POWER TRAIN

10 NHTSA complaints · 2021-10-07 → 2026-07-21

I was driving on the highway when my car started operating like it was in neutral. RPMs was high but the car started to stall and slow down and because of it I had to immediately pull over. The car would not go into gear. I attempted to put it in…
Owner report, NHTSA ODI #11577420
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
Owner report, NHTSA ODI #11733441
there was an abnormal roaring sound coming from the engine compartment. There was no warning light illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the transmission. The contact was informed there were metal fragments inside
Owner report, NHTSA ODI #11648760

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Steering assist reduction and steering gear failure

STEERING

9 NHTSA complaints · 2024-01-29 → 2026-05-19

I have a 2021 Chevy Blazer that has 31,0000 miles and my steering locked up. I was driving and barley got into a parking lot. Told by a certified dealer it is the power steering gear and possible the power steering module. No parts available and no…
Owner report, NHTSA ODI #11635399
The vehicle showed an error on the dash which stated "Action Required Steering Assist is Reduced Drive with Care" I tool the vehicle to the dealer I purchased it from McClusky Chevy at Kings Auto Mall in Mason Ohio. They informed me that the error code is…
Owner report, NHTSA ODI #11738765
The contact stated while driving 69-70 MPH, the steering wheel strongly pulled to the left side and into the roadway median. There was no warning light illuminated. The contact stated that the vehicle hit the median and bounced, facing incoming traffic
Owner report, NHTSA ODI #11539220

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Brake system failure including vacuum pump and pedal stiffness

SERVICE BRAKES

11 NHTSA complaints · 2021-05-04 → 2025-07-30

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
Owner report, NHTSA ODI #11676544
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
Owner report, NHTSA ODI #11670018
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
Owner report, NHTSA ODI #11675890

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Infotainment system "Update Failed" rendering screen inoperable

ELECTRICAL SYSTEM

2 NHTSA complaints · 2025-03-19 → 2025-03-31

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…
Owner report, NHTSA ODI #11650964
when I start my vehicle, my infotainment screen that I use for GPS and other features that are included in the safety of the car, and the screen just says, “Update Failed, Return to Dealer.”. The service advisor at Chevy says that this happens and…
Owner report, NHTSA ODI #11649907

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Camshaft carrier oil leak attributed to sealant application

ENGINE

2 NHTSA complaints · 2024-05-07 → 2026-04-28

Both camshaft carriers failed due to a manufacturing defect. According to NHTSA bulletins 21-NA-240 and PIP5755, the oil leak from the cam carrier is caused by improper sealant application during manufacturing. Although the dealer addressed the issue, it was clearly not a…
Owner report, NHTSA ODI #11734437
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
Owner report, NHTSA ODI #11731606

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Source: NHTSA Office of Defects Investigation (ODI). Complaint data refreshed Sep 11, 2026. Investigation data refreshed Sep 11, 2026.

We display NHTSA's record with attribution; we don't editorialize on what these complaints mean for any specific vehicle.

Essential maintenance

Critical for safety and preventing major damage

Engine Oil & Filter (per Oil Life System)

Every 7,500 mi

Change oil when the Oil Life System reaches 0% or every 12 months — whichever comes first. dexos1-approved synthetic oil required on all gas engines since 2011.

Estimated cost — typical U.S. ranges

Dealer

~$120–$160

Shop

~$85–$115

DIY

~$25–$55

Full synthetic costs more than conventional. 5-quart 0W-20 + filter is the typical bill.

Tire Rotation

Every 7,500 mi

Rotate tires every 7,500 miles. Silverado 4x4 and Tahoe owners benefit from earlier rotations to even out drivetrain wear.

Estimated cost — typical U.S. ranges

Dealer

~$85

Shop

~$60

DIY

Free

Often free at the shop where you bought the tires — worth asking before paying.

Brake Inspection

Every 7,500 mi

Inspect brake pads, rotors, and parking brake at each tire rotation. Equinox and Malibu front pads typically last 40,000-50,000 miles.

Estimated cost — typical U.S. ranges

Dealer

~$85

Shop

~$60

DIY

Free

Most shops do this free as a courtesy with any service. Don't pay separately if you can avoid it.

Brake Fluid

Every 45,000 mi

GM specifies brake fluid replacement based on contamination testing. Test every 30,000 miles; replace if moisture content exceeds 3% or fluid appears dark.

Estimated cost — typical U.S. ranges

Dealer

~$180–$200

Shop

~$125–$140

DIY

~$10–$25

DOT 3 or 4 — match the cap. Vacuum bleeders make this a one-person DIY.

Important maintenance

Keeps your vehicle running smoothly and efficiently

Engine Air Filter

Every 45,000 mi

GM long-life cellulose air filters are rated 45,000 miles. Direct-injection engines are sensitive to airflow restriction; inspect at every oil change.

Estimated cost — typical U.S. ranges

Dealer

~$60–$95

Shop

~$45–$70

DIY

~$15–$40

5-minute job on most cars; the airbox lid usually has clips, no tools needed.

Automatic Transmission Fluid

Every 45,000 mi

Severe service (heavy towing, frequent stop-and-go, dusty conditions): replace every 45,000 miles. Normal service: 97,500 miles. Use Dexron-VI on 6L80/8L90 transmissions.

Estimated cost — typical U.S. ranges

Dealer

~$330–$500

Shop

~$235–$355

DIY

~$60–$180

Some sealed transmissions have no dipstick — fill is precise and best left to a shop. Many drivers can still DIY drain-and-fill.

Transfer Case Fluid (4WD)

Every 45,000 mi

Silverado 4WD and Tahoe 4WD: replace transfer case fluid every 45,000 miles, sooner if towing or off-roading. Use GM Auto-Trak II fluid.

Estimated cost — typical U.S. ranges

Dealer

~$105–$140

Shop

~$75–$100

DIY

~$15–$40

AWD/4WD vehicles only. Easy drain-and-fill on most platforms.

Spark Plugs

Every 100,000 mi

GM iridium spark plugs are rated 100,000 miles on most LS and LT engines. The 5.3L V8 in Silverado 1500 commonly fouls plugs early under heavy idling.

Estimated cost — typical U.S. ranges

Dealer

~$285–$390

Shop

~$200–$275

DIY

~$25–$100

Iridium plugs cost more but last 100k+ miles. V6/V8 access varies wildly — some are tough.

Dex-Cool Engine Coolant

Every 50,000 mi

GM Dex-Cool (orange): first change at 150,000 miles or 5 years, then every 50,000 miles. Mixing with green coolant creates a sludge that destroys the cooling system.

Estimated cost — typical U.S. ranges

Dealer

~$285–$330

Shop

~$200–$235

DIY

~$25–$60

Use the manufacturer-specified coolant — wrong color/chemistry can damage the cooling system.

Rear Differential Fluid

Every 50,000 mi

Silverado and Tahoe: replace rear axle fluid every 50,000 miles, or 25,000 miles if towing. Limited-slip differentials require GM friction-modifier additive.

Estimated cost — typical U.S. ranges

Dealer

~$150–$195

Shop

~$105–$135

DIY

~$20–$50

Drain plug + fill plug — straightforward DIY. AWD vehicles have two; budget for both.

Recommended maintenance

Extends the life of your vehicle and improves comfort

Cabin Air Filter

Every 22,500 mi

Replace the cabin air filter every 22,500 miles. Silverado and Tahoe owners in dusty climates should replace earlier.

Estimated cost — typical U.S. ranges

Dealer

~$60–$95

Shop

~$45–$70

DIY

~$15–$40

Usually behind the glovebox. Shops charge labor for a 10-minute job — easy DIY win.

Fatal crash history & reported problems

Occupant deaths in fatal crashes (FARS)

10 crashes 2010–2024

FARS counts every occupant death in a fatal crash, whatever the cause — it does not mean the vehicle was at fault or defective. Counts are not adjusted for how many of each vehicle are on the road. How to read this number

Owner-reported problem signals

Separate from the federal fatality data above: complaints owners filed with NHTSA about this year and model. These are reports of problems, unverified, and are counted here only as signals.

6

complaints mentioning a crash

1

complaints mentioning a fire

Reviewed known issues for this vehicle·Open recalls for this vehicle

Typical U.S. ranges. Actual quotes vary by shop, parts choice, and vehicle condition.

How we estimate: Dealer = OEM parts × 1.4 + labor × $165/hr. Shop = parts + labor × $115/hr. DIY = parts only.

This maintenance schedule for the 2021 Chevrolet Blazer reflects Chevrolet's published service intervals and the Oil Life System system. Your actual service needs may vary based on driving conditions, climate, and vehicle usage. Always consult your owner's manual for model-specific recommendations.