2020 Chevrolet Blazer: stuck in gear or won't shift

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 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 Dec 17, 2025 · Engine, Steering · MO

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 to the dealership where they advised me the transmission went out. It was covered under the drivetrain warranty, but the GM warranty doesn't cover rental. It took almost 4 weeks for GM to approve for a new transmission due to parts being on back order to rebuild my transmission. Several months later, I was driving down the road when the ESC light and then it said "shift to neutral & press start" and I lost power. I coasted into a parking lot, got it fired up, but had no air conditioning (of course it was summer). Took it to the dealer and they said my radiator and A/C Compressor had to be replaced. Luckily my extended warranty covered the $5000 repair. Now 4 months later I got "steering assist reduced, drive with care" with codes. Took to shop and the codes basically was the temp was to low, but the shop couldn't find anything wrong. Cleared the codes and so far so good, but now my ESC light pops on once a week again. I don't even have 60,000 miles on my vehicle.

Filed Jun 26, 2025 · Transmission · FL

The contact owns a 2020 Chevrolet Blazer. The contact stated that while his wife was driving 80 MPH, the vehicle failed to accelerate as intended while depressing the accelerator pedal. In addition, the contact stated an abnormal sound could be heard coming from the engine. The vehicle stalled and the contact's wife was unable to move to the side of the road. The message "Shift to neutral and press the start button" was displayed. The police assisted with traffic control while the vehicle was pushed to the side of the road. The vehicle failed to start. The contact stated that prior to the most recent failure, the gear shifter would be stuck in park(P). The contact would move the gear shifter several times to cause it to move. The contact stated that the failure recurred several times, and the vehicle responded as needed after several attempts. After several attempts, the check engine light was illuminated. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure and referred the contact to the NHSTA Hotline for assistance. The approximate failure mileage was approximately 40,000.

Filed Nov 30, 2023 · Engine · OK

The car repeatedly has an error pop up that states steering assist is no longer activated and to drive with caution. The thermostat during this is also fully on cold. The check engine comes on after. The sensor and thermostat are repaired based on the code and problem persists. Same problem all over forums but Chevy refuses to fix as no recall. This is very concerning as the car may randomly go into limp mode while driving on the highway at 70mph putting at risk for crashing. The steering assist is also out putting at further risk. This is despite fixing and clearing the codes shown. This is a known issue that Chevy is refusing to address/recall.

Filed Sep 5, 2023 · Electrical, Transmission · MS

Unknown car will not shift into park without me having to re-shift to park and then the vehicle will shut off after re-shifting.

Filed Aug 7, 2020 · Transmission · 1,500 miles · DC

With approximately 1500 miles on the vehicle, the blazer's automatic transmission failed while driving. I was stopped at a red light. When the light turned green, I proceeded slowly through the intersection in a left turn. As soon as I left the intersection, just as the vehicle would typically up-shift, the RPM spiked, the vehicle jolted forward, and the check engine light came on. After the initial jolt, the vehicle would not shift out of first gear. I found a safe place to park and stopped the engine. Upon restarting, the engine light remained on and, though I could put the car in drive, the vehicle would not shift out of first gear. Moreover, when I tried to engage reverse, the car remained in neutral. I had it towed to a chevrolet dealership which informed me gm has a bulletin on the transmission requiring technicians not to attempt to repair it, but to install a new transmission.