This preliminary informational (PI) bulletin provides information to dealership personnel that may be helpful when addressing underbody component corrosion with customers.
full bulletin at NHTSA ↗2020 Chevrolet Blazer steering problems
moderate 39 complaints filed with NHTSA · avg repair $700 · see steering across all vehicles →
Complaints
39
Recalls
0
Avg fix
$700
What stands out
Of the 5 model years of Chevrolet Blazer we track for steering problems, this one carries the most owner complaints on file — 39.
Owners have filed 39 steering complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering steering on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This service bulletin provides a procedure to add deadener to the batter tray bracket to correct customer concerns of a Service Engine Soon (SES), Reduced Power, Service Brake, Reduced Steering and/or Stabilitrak Message Illuminated on DIC, multiple DTCs.
full bulletin at NHTSA ↗This informational bulletin instructs the tech when fuel/fluid is needed to be tested and where it can be sent for analysis.
full bulletin at NHTSA ↗This service bulletin provides a procedure inspecting for excess grease or Sealant on the Exterior of the steering gear due to seeing grease or sealant on certain locations on the gear.
full bulletin at NHTSA ↗This informational bulletin provides a guide on how to diagnose and test for vibrations utilizing the PicoScope.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The dominant complaint across 33 narratives is a cascade of warnings tied to a coolant temperature sensor malfunction. Owners report the temperature gauge stuck on "C," check engine codes P0128 or P01F0, AC blowing warm air, radiator fan locked at full speed, and most critically, a "Steering Assist Reduced" warning that makes the steering wheel stiff and difficult to turn—often between 50,000 and 70,000 miles, though some see it at 1,000 miles or even eight days after purchase.
The pattern is consistent: dealerships replace the thermostat and coolant temperature sensor, the vehicle runs normally for a few days, then the fault reappears after a battery disconnect or code clear. Some owners have replaced these parts multiple times with no lasting fix. One owner notes the coolant sensor harness is routed near coil pack wiring, suggesting possible electrical interference; no manufacturer fix addresses this.
A secondary but serious failure mode is transmission issues—jerking, slipping in lower gears, and complete transmission failure around 50,000 miles (covered by drivetrain warranty but delayed by parts shortages). Vehicle stability also suffers: some owners report swaying and difficulty holding lanes at highway speeds.
GM has issued Technical Service Bulletins but refuses free repairs, claiming these are warranty issues outside their scope. No recall has been issued despite the widespread nature of the complaint and the clear safety risk to steering control.
Same Chevrolet Blazer steering reports on nearby years: 2019 · 2021
Failure modes owners describe
Coolant Temperature Sensor / Thermostat Circuit Malfunction
Engine control module receives false or erratic coolant temperature signal, typically reading cold despite warm engine. This triggers cascading limp-home responses: check engine light, reduced steering assist warning, AC shutdown, and maximum fan speed. Owners report the fault clears temporarily after battery disconnect or scan-tool reset, then reappears within days to weeks. Dealership thermostat and sensor replacement does not resolve the underlying issue; fault returns shortly after repair.
When: Typically 49,000–70,000 miles; one case reported at 1,000 miles and another at 8 days of ownership
Symptoms owners cite: Check engine light with codes P0128 and/or P01F0; Temperature gauge reads 'C' (cold) continuously; AC blows warm or hot air; Radiator fan runs at maximum speed continuously; Steering assist reduced warning on dashboard; ESC (electronic stability control) warning lights; Remote start becomes inoperable; Fault clears temporarily after battery disconnect or code clear, then returns
Codes mentioned: P0128, P01F0, P62F
Repairs/costs cited: Dealership replaces thermostat and coolant temperature sensor; repair cost cited as $800–$1,100. Replacements do not resolve recurrence. One owner notes OEM thermostats unavailable in stock, suggesting widespread supply issue.
Recalls/TSBs owners mention: GM issued Technical Service Bulletins (TSBs) but refuses to perform repairs free of charge. No recall issued. GM warranty covers drivetrain (transmission) but not coolant/steering electrical failures in some cases. Extended warranty covered one $5,000 A/C compressor and radiator replacement.
Electric Power Steering Assist Loss
Steering becomes significantly harder and less responsive when 'Steering Assist Reduced' warning appears. The electric power-steering system loses or severely degrades assist, requiring greater physical effort to turn the wheel, especially at low speeds or during maneuvers. This correlates with the coolant temperature sensor fault but is treated as a separate symptom by owners. Dealership diagnostics frequently fail to replicate the issue or identify a root cause.
When: First reported around 50,000–55,000 miles; one case at startup; ongoing intermittent occurrences
Symptoms owners cite: Steering wheel becomes stiff and difficult to turn; Dashboard warning: 'Steering Assist is Reduced – Drive with Care'; Sudden onset; sometimes random (at startup, mid-drive); Steering becomes unsafe in traffic or during lane changes at highway speed; In one case, steering became completely inoperable and vehicle became undrainable
Repairs/costs cited: Dealership diagnosis attributes the steering issue to failed thermostat in some cases, but replacing thermostat does not resolve steering assist loss. One owner replaced battery per dealership recommendation; issue returned within one week. No successful permanent repair cited.
Recalls/TSBs owners mention: Manufacturer notified in multiple complaints; no recall or warranty service offered. Dealerships unable or unwilling to diagnose root cause.
Transmission Noise and Jerking (Possible Slipping)
Transmission exhibits harsh shifts, RPM flare-ups, jerking forward under light acceleration, and difficulty engaging reverse. One owner reported complete transmission failure at 54,000 miles (covered under drivetrain warranty, rebuild took 4 weeks due to parts backorder). Another reports transmission slipping during lower-gear acceleration and refusing to move when put into reverse. These incidents often occur without warning and are frequently non-reproducible at the dealership.
When: As early as 1,000 miles (stability/swaying complaint); around 50,000–55,000 miles for severe slipping and failure
Symptoms owners cite: RPMs rapidly increase without proportional acceleration; Vehicle jerks or lunges forward when accelerating below 20 mph; Harsh, grinding noises when engaging reverse; Vehicle stuck in park or unable to move; Transmission slips in lower gears; Complete loss of power transmission (in one case)
Repairs/costs cited: One owner's transmission rebuilt under GM drivetrain warranty at dealership (4-week wait for parts, no rental coverage). Parts shortage on back order noted. Repair cost covered by drivetrain warranty; extended warranty covered subsequent issues.
Recalls/TSBs owners mention: Drivetrain warranty covers transmission rebuild. No recall or TSB cited for transmission shifting issues.
Vehicle Stability and Steering Control Issues at Low Mileage
At very low mileage (1,000 miles reported), vehicle exhibits instability: swaying side-to-side during highway driving, difficulty maintaining lane position, and stiff steering. Dealership diagnostics find no fault. Appears to be related to electrical/sensor issues stemming from the coolant temperature circuit malfunction or its cascading effects on stability control.
When: As early as 1,000 miles; persists on some vehicles
Symptoms owners cite: Vehicle sways and is unstable to steer; Difficult to maintain lane position at highway speeds; Stiff steering; No warning lights or codes visible to owner
Repairs/costs cited: Dealership unable to identify or replicate failure.
Recalls/TSBs owners mention: Manufacturer notified; no assistance provided.
A/C Compressor and Radiator Failure (Secondary to Coolant Sensor Fault)
AC compressor and radiator fail, requiring replacement. These failures appear secondary to the coolant temperature sensor fault causing prolonged maximum fan speed and incorrect coolant circulation. One owner's A/C compressor and radiator replacement cost $5,000 and was covered by extended warranty.
When: Around 50,000–55,000 miles
Symptoms owners cite: AC stops blowing cold air; Loss of air conditioning function; Radiator overheat conditions (inferred from max fan speed)
Repairs/costs cited: A/C compressor and radiator replaced at dealership. Cost $5,000; covered by extended warranty only, not standard warranty.
Recalls/TSBs owners mention: No warranty coverage on standard warranty; extended warranty covered repair.
ESC (Electronic Stability Control) Malfunction
ESC warning light illuminates, particularly after auto-stop/start feature engages and engine restarts. When auto-stop/start is disabled, ESC warning does not appear. This suggests the fault is tied to the coolant temperature signal loss during engine restart cycles.
When: Recurring; correlates with auto-stop/start feature use
Symptoms owners cite: ESC warning light on dashboard; Warning appears after auto-stop/start cycle; Warning disappears if auto-stop/start is disabled
Repairs/costs cited: Dealership replaces thermostat and coolant sensor; issue recurs.
Recalls/TSBs owners mention: No specific recall or TSB for ESC issue; addressed alongside thermostat replacement.
Possible Wiring Harness Interference (Coolant Sensor / Coil Pack)
One owner and multiple online sources cite coolant temperature sensor harness routed together with coil pack wiring, causing electrical or RF interference that triggers false cold-temperature signals. This would explain why thermostats and sensors test good after replacement but fault persists. The issue may be design-level.
When: Early in ownership; recurring throughout vehicle life
Symptoms owners cite: Check engine code P0128 or P01F0; Temperature reading stuck on cold; Fault does not clear permanently despite parts replacement
Codes mentioned: P0128, P01F0
Repairs/costs cited: No corrective repair cited; wiring harness rerouting or shielding suggested but not performed by dealership.
Recalls/TSBs owners mention: No manufacturer acknowledgment of wiring harness issue or design defect.
Synthesized from 39 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 2 most recent
There seems to be a constant problem with the service driver assist error code popping up and check engine light coming on. The ac heating keeps losing temperature. I've looked for support for this issue and it seems to be a common problem for chevy owners. Why isn't there a recall on this.
Where do I start. Spring of 2024 I believe, less than 55,000 miles, my transmission went out. No warning. I just went out to my vehicle to go to work and when I put it into reverse, my vehicle make a awful noise, jerked forward almost going into my garage door, then wouldn't move.. I put it back in park, tried to put into reverse again and it wouldn't go. It was stuck in park. Had to get it towed…
Had steering trouble with your 2020 Chevrolet Blazer?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the steering problem on the 2020 Chevrolet Blazer?
It's a documented issue but not catastrophic. 39 complaints have been filed. Repairs average $700 and most owners catch it before it causes a breakdown.
At what mileage does the steering typically fail?
Based on the 39 complaints filed, steering issues most often appear around 23,933 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $700 for steering repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to steering?
No active recalls currently cover steering issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2020/Chevrolet/Blazer.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.