2020 Chevrolet Blazer transmission problems

Filed Oct 22, 2026 · Engine, Steering · MI

2020 Chevy Blazer LT 3.6 L V6 I'm filing this complaint regarding multiple concerning mechanical and safety related issues with my 2020 Chevy Blazer LT that I purchased brand new and currently have 54,224 miles . Without warning, My vehicle developed several problems simultaneously. The check engine light came on, The engine cooling fan started running continuously at high speed, the AC stopped blowing cold air and is warm air, the steering assist reduced came on and my chevy app notified me that I have an engine cooling system malfunction and to service now. It's showing a P0128 code when I had it checked. After doing some research, I discovered GM issued a thermostat special coverage program for certain vehicles 2021-and newer models. Mine isn't part of it because of the year and isn't covered by the power train warranty for the same reason even though they all have the same engine. I only have 54,000 miles! I'm very concerned over the steering assist being reduced! What if the steering goes out while I'm driving? I have my grandchildren all the time. I need my car! There are several other complaints on here for the same vehicle and the same problem! Why isn't the 2020 Blazer covered under this special coverage program? The dealerships all say it's a well known problem! I believe this issue deserves investigation !

Filed Oct 8, 2026 · Engine, Steering · TN

The thermostat is malfunctioning along with engine temperature coolant sensor. This causes the temperature gauge on the dashboard to be completely disabled and not moving off cold, it disables the air conditioner, makes the engine cooling fan to run extremely high nonstop, and places the vehicle into an unpredictable limp mode or fail safe mode. This was identified as faulty by GM and they have issued a special service bulletin that they will repair it up to a 150,000 miles or 15 years or reimburse customers up to $1200 on 2021 models. The 2020 models use the same engine and parts but they refuse to include them which is an unfair exclusion since they admitted to a faulty part. 2020 should be included with the same 150,000 miles and 15 year coverage or reimbursement.

Filed Sep 19, 2026 · Electrical, Transmission · PA

This happened back in May and the dealership couldn’t find anything wrong and it happened again today. I am driving and the car will shut off. A message pops up saying shift to neutral and press start again. It’s very dangerous and frustrating.

Filed Aug 22, 2026 · Electrical, Transmission · TN

The car is not sensing that it is in park when it is. When I place it in park and turn the car off it dings and says shift into park however it already is in park. Therefore the car will not turn off. I had to jiggle the shift or turn the car on, reverse then go forward then park to get it to register. This has taken up to 10 minutes and it’s getting worse. This is a known issue that is referenced in GM Technical Service Bulletin 19-NA-206.

Filed Jul 12, 2026 · Brakes, Transmission · MI

Last year I was heading to heading to [XXX] in XXX when I pushed on the brakes on my 2020 Chevy blazer my brakes were working but the steering wheel was shaking weird like I was hard on the brakes but I was tapping them slowly earlier this year right before I had transmission flush at fox Chevy in Caledonia I noticed before two weeks of bringing it in I was near a traffic light slowing down it went hard shift down and when I was not moving in notice it jerked forward when at idle and the light like it was rear ended I feel like this is a safety concern of that happening after the transmission flush for two months after doing the acceleration is slipping I feel like there should be a recall for torque and transmission recalls for the 2020 Chevy blazers I really love this blazer owned for 4 years now I feel like it would be a safety for the public and nationwide INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jun 17, 2026 · Transmission · AL

I am submitting this complaint regarding the transmission in my 2020 Chevrolet Blazer. My vehicle has fewer than 100,000 miles and has experienced significant transmission failure symptoms, including hard shifting, jerking during acceleration, RPM fluctuations, slipping, loss of normal power, and inability to safely reach highway speeds. The vehicle struggles to accelerate properly and at times will not shift correctly into higher gears. Diagnostic trouble codes related to transmission operation have been present, including pressure control solenoid and transmission control faults. Repairs have already been attempted, including replacement of transmission-related components, but the transmission continues to malfunction. Through online owner groups, forums, and discussions with other Chevrolet Blazer owners, I have found numerous reports from owners experiencing similar transmission problems in 2019-2022 Chevrolet Blazers. Many owners report transmission slipping, harsh shifting, torque converter issues, valve body failures, pressure control solenoid failures, and complete transmission replacement at relatively low mileage. These failures create a serious safety concern because the vehicle may hesitate, lose power, fail to accelerate properly when entering traffic, or be unable to maintain safe highway speeds. Drivers and passengers are placed at risk when a vehicle cannot respond normally during merging, passing, or other traffic situations. Owners are frequently being quoted between $7,000 and $12,000 for transmission replacement or repair despite the vehicles being relatively new and often having less than 100,000 miles. Many consumers believe these failures indicate a widespread defect rather than normal wear and tear. I request that the federal safety agency investigate transmission failures in the 2020 Chevrolet Blazer and related model years to determine whether a manufacturing or design defect exists and whether a recall or other corrective action is warranted.

Filed Jun 11, 2026 · Transmission · WA

I am submitting this complaint regarding my 2020 Chevrolet Blazer and what appears to be a widespread cooling system defect. My vehicle has developed a coolant smell outside the vehicle, which raises concerns about a coolant leak from the radiator. After researching the issue, I discovered that numerous Chevrolet Blazer owners have reported similar coolant-related problems, including radiator failures, coolant leaks, and persistent coolant odors. These complaints are widely discussed across online forums, social media, and owner groups. General Motors appears to be aware of this recurring issue, yet many owners continue to experience failures within and outside of warranty coverage. The coolant smell is concerning because it may indicate a leak within the cooling system, which could lead to overheating, engine damage, loss of vehicle reliability, and potential safety risks while driving. Owners should not be experiencing major cooling system failures on relatively modern vehicles. I request that the federal safety agency investigate the cooling system and radiator issues affecting the 2020 Chevrolet Blazer and determine whether a defect exists that warrants a recall or other corrective action. The number of similar complaints suggests this may be a systemic issue rather than isolated incidents. General Motors should be held accountable for addressing this widespread problem and providing a permanent repair solution for affected owners. Thank you for your attention to this matter.

Filed May 27, 2026 · Engine, Transmission · MI

Engine temp gauge stops working causing the air to stop working and the cooling fan to rev to highest rpm. Also a warning that the steering assist is reduced. Eng check light comes on with a code P0208. This a known problem with an extended service # (N242484760) but only if your vin is listed. All vehicles with this problem should be covered

Filed Apr 7, 2026 · Engine, Steering · MI

| Issues first appeared recorded on 3/9/2026, while odometer read 49,663 miles. Check engine light was caused by error codes P0128 and P01F0. This causes the following issues: * Check engine light to appear on the dashboard. * Engine temperature gauges to be unreliable at times or completely non functional at others, as it will constantly read the engine temperature "Cold". * Air conditioning unit to become unreliable at times or completely non functional at others, and only blow hot air. * Radiator fan will be stuck running at max speed despite current engine temperature. * A "Reduced Steering Assist" message will periodically appear on the dashboard. * A "Service ESC" message will periodically appear on the dashboard. * Remote start will becomes non functional. | Car was taken to a license Chevrolet dealership and had full thermostat housing and thermostat sensors replaced. Dealership confirmed all replaced parts are working correctly and as intended. After picking up the vehicle from the dealership, and driving car for roughly 30 miles, the check engine light appeared on the dashboard again causing all previous issues to return. | Several other Chevy Blazer 2020 owners have complained of the same issue online, and in forums such as: [XXX] . | INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Mar 17, 2026 · Electrical, Engine · KS

Just took my car to the Chevy dealership today and had them go over the car because I keep getting the message steering assist has been reduced and the fan is constantly running at the highest speed and it also makes it where I can not use the a/c or heat in the car! I don’t know the code off hand but it has something to do with the cam shaft and the thermostat for the antifreeze! From what Chevy told me today it is a $9000 job to tear down the left side of the engine because the camshaft carrier gasket is leaking oil! Which is probably why that code is popping up. Or from what I was told today it could be from the battery which I believe they were trying to shift blame. Either way this camshaft stuff really needs to be investigated!!