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.
Chevrolet Blazer won't shift problems
35 of the 8,038 owner complaints about the Chevrolet Blazer describe stuck in gear or won't shift, most of them for the 2020 model year.
- owner complaints
- 35
- worst model year
- 2020
- typical repair cost reported
- $1,200
- typical mileage
- 66,000
By model year
Often reported together
Transmission failure 10Check engine light 5Loss of power 4Stalling 2Jerking 2Grinding brakes 2ABS 2Wipers 1
Trouble codes mentioned
P2101 2
What owners say
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.
This submission is an additional report related to the federal safety agency complaint #11714381. At approximately 55,000 miles, my 2021 Chevrolet Blazer experienced a sudden throttle body failure while driving. The vehicle entered reduced engine power/limp mode without warning and acceleration was significantly limited. This created a safety concern while driving in traffic, particularly when merging and crossing intersections. Diagnostic code P2101 (Throttle Actuator Position Performance) was present. A Chevrolet dealer confirmed an internal throttle body failure and replaced the throttle body assembly. Although the repair was completed, this failure occurred at relatively low mileage for a critical engine control component. A sudden loss of acceleration can pose a safety risk depending on traffic conditions. Since filing my original complaint, I have identified multiple similar reports online and in owner forums describing premature throttle body failures in GM vehicles with similar symptoms (reduced power/limp mode and limited acceleration). This suggests the possibility of a broader pattern involving this component. I am submitting this additional report so that the federal safety agency has a complete record of the incident and potential pattern of premature throttle body failures. If this issue is widespread, it may warrant further review or investigation as it affects vehicle acceleration and safe operation.
Around 55,000 miles, my 2021 Chevrolet Blazer experienced a throttle body failure. The check engine light illuminated and the vehicle entered a reduced power/limp mode condition. Throttle response was significantly limited, and the vehicle could not accelerate normally. While the vehicle remained drivable, it took substantially longer to reach speed, which could pose a safety risk when merging into traffic or crossing intersections. Diagnostic trouble code P2101 (Throttle Actuator Position Performance) was present. A Chevrolet dealer confirmed an internal throttle body failure and replaced the throttle body assembly. This component is a critical engine control system, and failure could affect acceleration and vehicle control, posing a potential safety risk. The failure occurred well before expected service life and required a costly repair. The component has been replaced and is available for inspection upon request. I believe this may represent a premature defect and should be investigated for similar failures in other vehicles.?
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.
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.
Vehicle gear shifter is stiff and difficult to pass from Park to Drive--the gear shifter gets stuck in Neutral often. The Entire Dash and instrument cluster goes black during driving and will not come back on until hours later even after the vehicle has been turned off and back on. This has caused me to be unable to see my speed, turn signals, fuel gauges or any engine controls. This leaves me unable to operate or control my vehicle. This is a huge safety issue when driving as I am unable to determine my speed or see any of my vehicles controls or warnings. The front passenger seat motor has a horrible vibration and struggles to adjust the seat properly. I have contacted multiple dealerships on multiple occasions regarding these issues and have been told that the extended warranty will not cover any of these issues although I was told it would when I purchased. Chevy has refused to offer assistance with Towing the vehicle to a dealership when the cluster stops working and encourages me to drive a vehicle that is not operational. The service manager at one location told me this was a known issue with the vehicle.
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 drive ajd press the acceleration pedal but it just revved. Same with putting it in reverse. It's a safety concern because my car could not maintain highway speed and abruptly went stagnant. I had the vehicle towed to dealer and they replaced the entire transmission system. The car always had a shudder feel to it when accelerating from 0 onwards to 40 mph.The day this occurred there was no blatant warning signs.
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.
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.
Related recalls
Power train: automatic transmission
- What is wrong
- General Motors, LLC (GM) is recalling certain 2023 Cadillac XT6, GMC Acadia, Chevrolet Blazer, Traverse, and 2022-2023 Cadillac XT5 vehicles. The transmission may have been built with an incorrect sun gear, which can result in the driver-side half-shaft disengaging from the transmission.
- Risk
- A half-shaft disengaging from the transmission can result in a loss of drive power or vehicle rollaway when the vehicle is placed in park. Either of these scenarios can increase the risk of a crash.
- Remedy
- Dealers will replace the sun gears, free of charge. Owner notification letters were mailed on July 27, 2023. The remedy is expected to become available August 31, 2023. Owners may contact Cadillac customer service at 1‑800‑458‑8006, Chevrolet customer service at 1‑800‑222‑1020, or GMC customer service at 1‑800‑462‑8782. GMC's number for this recall is N222389310.
Recall number 23V172000 · Recall details
Power train: driveline: driveshaft
- What is wrong
- General Motors, LLC (GM) is recalling certain 2023 Chevrolet Blazer and Traverse vehicles. The left-side half-shaft assemblies may be missing a retaining ring.
- Risk
- A missing retaining ring on the half-shaft can cause half-shaft inner joint separation, resulting in a loss of drive power or vehicle rollaway when the vehicle is placed in park. Either of these scenarios can increase the risk of a crash.
- Remedy
- Dealers will replace the left-side half-shaft assembly, free of charge. Owner notification letters were mailed February 23, 2023. Owners may contact Chevrolet customer service at 1‑800‑222‑1020. GM's number for this recall is N222390180.
Recall number 23V042000 · Recall details
Power train: automatic transmission
- What is wrong
- General Motors LLC (GM) is recalling certain 2018-2019 Chevrolet Cruze and Buick LaCrosse, 2018-2020 Chevrolet Equinox, Chevrolet Traverse and GMC Terrain, 2018 Chevrolet Malibu, 2019-2020 Buick Encore, Buick Enclave, Cadillac XT4, Chevrolet Blazer and GMC Acadia, and 2020 Cadillac XT6 vehicles. The start/stop accumulator endcap may have missing bolts.
- Risk
- Missing bolts on the start-stop accumulator endcap could result in a transmission oil leak and may progress to a loss of propulsion, increasing the risk of a crash. A transmission fluid leak in the presence of an ignition source may increase the risk of fire.
- Remedy
- GM will notify owners, and dealers will inspect the start-stop transmission accumulator and replace it if any bolts are missing, free of charge. The recall began December 15, 2020. Owners may contact GMC customer service at 1‑888‑988‑7267, Buick Customer service at 1‑866‑608‑8080, Chevrolet customer service at 1‑800‑222‑1020 or Cadillac customer service at 1‑800‑458‑8006. GM's number for this recall is N202313440.
Recall number 20V668000 · Recall details
Power train: automatic transmission
- What is wrong
- Significant wear can develop on the low and reverse clutch preventing the park pawl from engaging. This can prevent a "no park" condition to occur while the engine is running, causing unintentional movement of the vehicle without operator action. (the "no park" condition will not occur while the engine is off.)
- Risk
- Unintentional vehicle movement could result in a vehicle accident and injury to persons in the path of the vehicle.
- Remedy
- Dealers will check the transmission fluid for contamination which will indicate if the low or reverse clutch is worn. If the transmission fluid shows contamination, the transmission will be replaced.
Recall number 94V093000 · Recall details
Questions about the Chevrolet Blazer won't shift
Which Chevrolet Blazer years have stuck in gear or won't shift problems?
The model years with the most reports are 2020 (7 complaints), 1997 (5 complaints) and 2000 (5 complaints).
How much does it cost to fix stuck in gear or won't shift on the Chevrolet Blazer?
Owners who mentioned a price put the repair at about $1,200 (median of 7 complaints that include a dollar amount). Costs vary with mileage, warranty and where the work is done.
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