736 of the
9,362 complaints filed about the Chevrolet Trailblazer
are about the transmission —
100% of everything owners reported.
The worst model year for it is 2002.
736
Complaints
100%
Share of all complaints
25
Crashes
12
Fires
Transmission & Drivetrain complaints by model year
The contact owns a 2006 Chevrolet Trailblazer. The contact stated that while driving, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. The vehicle jerked and vibrated abnormally. In addition, the thermostat temperature gauge increased, and the vehicle stopped. The contact stated that the vehicle failed to drive or reverse. The vehicle was towed to the residence.
NHTSA complaint #11762845 — an unverified report by a vehicle owner.
Dear Chevy, I am reaching out to you again because I am desperately requesting immediate assistance with my vehicle, which has now become an extremely serious and dangerous safety concern. On Friday, [XXX], I had my vehicle towed to the dealership because of the ongoing mechanical issues I have been experiencing. I was advised that the repairs would cost $877, which included a battery replacement and new sensors. I paid for these repairs and picked up my vehicle on Wednesday, September 2, 2026, believing that the issues had finally been addressed. Unfortunately, within approximately one hour of leaving the dealership, my check engine light came back on. When I arrived home, the key became stuck in the ignition. I immediately contacted the dealership and requested to speak with a Service Manager. I made this request approximately five separate times, yet I was unable to speak with a Service Manager until Friday, September 4, 2026, when I finally spoke with Matt. The situation has now escalated into an extremely dangerous and potentially life-threatening safety issue. On Sunday, [XXX], while driving on the [XXX] in Chicago, my vehicle completely shut off twice while I was actively driving. There were no warning sounds, no dashboard warning codes, and no indication that the vehicle was about to shut off. My vehicle suddenly lost power while I was on a busy expressway, creating an extremely dangerous situation and nearly causing a major accident/pileup. I genuinely feared for my life. A vehicle that unexpectedly shuts off while traveling at highway speeds is not something I can safely continue driving. After this occurred, I had the vehicle towed to my home. I later attempted to start it, and the vehicle did start; however, the key became stuck in the ignition again. This problem has been ongoing for over a year, and I have repeatedly and desperately asked for these issues to be properly diagnosed and repaired. I have already INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 5
NHTSA complaint #11762612 — an unverified report by a vehicle owner.
Original Owner of 2021 Chevy Trailblazer LT. Purchased new in April 2021. Vehicle has a history of major powertrain issues, starting with Check Engine light during its first year of ownership, culminating in a complete turbocharger replacement in December 2025. This only as a result of my research, after many visits to dealership trying to diagnose the issue. The check engine was consistently illuminated in the vehicle 2021-2025. 9 days ago while traveling the vehicle, experienced sudden oil pressure loss, and stalling risks, displayed a hard warning “ENGINE OIL PRESSURE LOW. STOP ENGINE”. On Star provided me with a diagnostic code of P0521, pointing to an engine oil pressure sensor malfunction. Apparently another widely known issue with this engine, there are TSBs stating after repair the code will return and Software Update required. Extended warranty has expired, dealership as well as GM corporate unwilling to provide any assistance with cost of diag, repairs, etc, leaving myself and disabled dependent stranded. Vehicle since purchase has been exclusively serviced through the purchasing dealerships service center. Maintenance regularly maintained. Service management has admitted knowledge of this issue with this engine, still reluctant to provide any additional assistance, informed me I’m on a waitlist for a possible loaner vehicle 4-6 weeks from now. There are several TSBs on this engine surrounding this issue. Apparently there is a known defect with the engine oil pump, cam shaft, evap purge pump. Strong possibility could be a result of the Turbo replacement, debris from that failing turbo could have blocked the oil system, causing starvation.
NHTSA complaint #11761820 — an unverified report by a vehicle owner.
The shift assembly is going bad and causing a Shift to Park error that GM is aware of. They have issued a Technical Service Bulletin about this exact part. The error code will cause the battery to run down leaving me stranded. The dealer has inspected the vehichle and ordered the necessary part to replace it. The vehicle has not been inspected by the manufacturer, police, insurance representatives or others but is available to have an inspection done. There were no warning lamps for this other than the Shift to Park error showing on the display when the car has been turned off. These error messages started happening around August 1, 2026.
NHTSA complaint #11757922 — an unverified report by a vehicle owner.
When I shut off the engine, it says “Shift to park” and the car will not turn off. To get it to turn off, I have to turn the car back on (usually multiple times), until it recognizes that it IS in park.
NHTSA complaint #11756073 — an unverified report by a vehicle owner.
I was driving down the highway when the 3 bolts holding the exhaust under the car broke off. My exhaust was dragging down the highway until I could safely get pulled over. The bolts are welded in of course so you can’t just put new bolts in you have to replace the whole catalytic converter, which is a pain to do unless you take it to the dealer and pay $2000.
NHTSA complaint #11754629 — an unverified report by a vehicle owner.
My trailblazer will not shift properly into drive from park or reverse. GM calls this a "loss of forward motion" or "delayed forward engagement" in their service bulletin TSB-24-NA-009. It is a safety issue because you never know when or how long the vehicle will take to engage and allow forward movement. This causes issues when leaving a parking spot or a driveway, especially on busy roads. If the car will not move forward, my family is stuck in the road until it finally engages into gear and allows forward movement. When this occurs, the vehicle engine will shutter and not allow any forward movement. I usually have to move the drive selector back to park and back to drive again. This creates an immediate and unreasonable safety risk because the vehicle will not move for several seconds while I am sitting in traffic. This generates a P2714 code. I had the car looked at by a GM dealer as well as an independent transmission repair shop and both indicate it will likely need a new transmission. GM is fully aware of the defect and has issued a service bulletin, TSB-24-NA-009 to instruct dealers how to diagnose and repair the problem. The bulletin proves a widespread engineering or manufacturing flaw exists. However, GM is treating this as a maintenance issue rather than the severe safety hazard that it is. It is my understanding, GM has since abandoned this transmission on the newer models, further indicating that GM knew these transmissions were not designed well. I am requesting the NHTSA office cross-reference my complaint with GM TSB-24-NA-009 and upgrade the component defect to a mandatory, manufacturer-funded safety recall before it causes a collision or fatal injury. Thank You
NHTSA complaint #11752367 — an unverified report by a vehicle owner.
The car showed an error message saying shift to park when trying to turn the car off. The car was in park and showed in park on the dashboard & shifter but the error message still said it wasn’t in park. While this error is showing it will not allow the car to shut off or lock doors. I have a little over 19k miles on this car and should not have this issue. After researching this has been a know issue with their vehicles for years and it still has not been addressed.
NHTSA complaint #11751636 — an unverified report by a vehicle owner.
Vehicle has 67,000 miles and suffered a catastrophic CVT transmission failure, documented by dealership diagnostic code P2714. The transmission severely slips and exhibits a dangerous 15-second delay to engage forward gear after shifting into Drive. More critically, the vehicle suffers from unpredictable engine stalling. The car completely shut down and stalled in traffic while trying to accelerate into a driving lane after shifting. The vehicle did not trigger any dashboard safety warnings, limp mode, or "Reduced Engine Power" messages prior to shutting down, causing an un-warned loss of motive power on a public road. This creates an immediate, severe risk of a high-speed rear-end collision. General Motors has acknowledged internal CVT chain slippage and hydraulic failure points in Technical Service Bulletins 24-NA-009 and PIP6033 but has not issued a safety recall.
NHTSA complaint #11750836 — an unverified report by a vehicle owner.
Component Affected: POWER TRAIN: AUTOMATIC TRANSMISSION / TRANSMISSION CONTROL MODULEDescription of Safety Defect:The vehicle is experiencing a severe, intermittent, and violent mechanical "garage shift" engagement lurch. This occurs specifically when shifting the gear selector from Reverse to Drive during a cold-start cycle.When the gear is selected, there is a distinct hydraulic delay followed by a violent mechanical slam that causes the entire vehicle to violently lurch forward. This unintended vehicle movement occurs even though the engine has naturally idled down completely below 1,000 RPM, and while the brake pedal is fully and firmly depressed to the floor.Safety Hazard and Consequences:This defect poses an immediate and severe safety hazard. The mechanical force of the lurch is strong enough to potentially overcome the vehicle's braking system or cause a foot-slip off the pedal, resulting in sudden, unintended vehicle movement. This creates a high risk of a low-speed collision, vehicle damage, or striking a pedestrian or property during tight parking or garage maneuvers. General Motors' internal service bulletins (such as Bulletin 24-NA-009) indicate known issues with sticking clutch regulator valves or solenoid over-travel causing line pressure spikes in these modern transmissions, yet no safety recall has been issued to permanently address this dangerous powertrain defect.
NHTSA complaint #11748264 — an unverified report by a vehicle owner.
Vehicle stalled and shut off while driving in moving traffic on multiple occasions, resulting in sudden loss of power steering and brake assist — a significant safety hazard. Battery failed at 32,860 miles (September 2025) with all low voltage codes. Battery replaced by dealer. Vehicle continued to exhibit stalling, no-start, and Battery Saver Active warnings. Dealer has been unable to resolve the recurring issue across three visits (RO 510659, RO 518708, RO 523715) at Chevrolet of Culver City, Culver City CA. Dealer is now attributing the fault to contaminated fuel without providing lab evidence. Active GM Customer Care case 1-02414837. Powertrain warranty active
NHTSA complaint #11746241 — an unverified report by a vehicle owner.
I am having issues with putting car in park. Keeps showing not in park and will not shut off until I yank on handle. Getting worse & taking so long. Took to dealership and they said probably the harness and would cost $400 to $600 to fix. My research shows they have had this issue since 2018!! Only recall I could find was in Ohio. I feel angry they still keep using a defective part and expect us to pay to fix. I am older and on fixed income & don't have the money. Also why should I when it's their ongoing issue. I'm scared of this not letting me shut off car till I run out of gas!!
NHTSA complaint #11743181 — an unverified report by a vehicle owner.
The contact owns a 2023 CHEVROLET Trailblazer. The contact stated that while parking the vehicle, the computer system failed to recognize that the vehicle had been shifted into the park position, causing a "Shift to Park" warning light to illuminate on the instrument cluster. Although the gear selector was physically in park, the contact was unable to fully shut down the vehicle and had to cycle the ignition on and off multiple times until the system eventually recognized the park position. The vehicle was driven to the dealer where it was diagnosed to be a transmission control assembly failure. The vehicle was repaired. The manufacturer was not notified of the failure. The failure mileage was 61,097.
NHTSA complaint #11736042 — an unverified report by a vehicle owner.
I am reporting a serious safety issue with my 2021 Chevrolet Trailblazer related to transmission failure. The vehicle has approximately 83,000 miles. While driving, the vehicle experiences a sudden loss of power when attempting to accelerate. In some instances, the vehicle has stalled or shut off while I was actively driving, creating a dangerous situation, especially when merging into traffic or driving through intersections. The issue is intermittent but has become more frequent over time. The vehicle does not respond properly when the accelerator is pressed, and there is a noticeable delay or complete lack of power. At times, the vehicle will not move as expected, which poses a significant safety risk. Diagnostic codes associated with this issue include P2714 and P0700, which indicate a transmission-related malfunction. I have been advised that the vehicle requires a full transmission replacement. This failure occurred at relatively low mileage for a major powertrain component, and I am concerned this may indicate a broader defect. The stalling and loss of power create a hazardous driving condition that could result in an accident. I am submitting this complaint to report a potential safety defect and to request further investigation into this issue.
NHTSA complaint #11734472 — an unverified report by a vehicle owner.
The contact owns a 2026 Chevrolet Trailblazer. The contact stated that while driving at various speeds, the vehicle failed to properly shift into gear while the gear shift lever was in use. The check engine and another unknown warning light were illuminated. The vehicle was towed to a local dealer, where several undisclosed fault codes were cleared. The vehicle was towed back to the same local dealer, where it remained for further investigation. The contact was informed that the transmission might need to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 100.
NHTSA complaint #11733036 — an unverified report by a vehicle owner.
The contact owns a 2022 Chevrolet Trailblazer. The contact stated that the vehicle failed to shift into park(P) as needed. The contact attempted to turn off the vehicle, and the message "Shift to Park(P)” was displayed. The contact jiggled the gear shift lever and the vehicle shifted to park(P and then turned off. The contact stated that the failure was intermittent, but was a recurring failure. The vehicle was taken to a local dealer to be diagnosed, and it was determined that the shift lever assembly needed to be replaced. The vehicle was repaired. The contact researched online and stated that it was a known failure. The manufacturer was informed of the failure and opened a case. The failure mileage was 47,304.
NHTSA complaint #11725509 — an unverified report by a vehicle owner.
My transmission is defective and past 60,000 miles but only a little. I had a diagnosis and it needs replacing like many of these trailblazers in the ongoing lawsuit. I cannot pay for it and it should not be broken!
NHTSA complaint #11723367 — an unverified report by a vehicle owner.
The 2024 Trailblazer developed a problem going into reverse at less than 17500 miles in December of 2025 when my daughter came home for Christmas. It would slam into reverse or freeze and then shift harshly. The selling dealer replaced the valve body in the transmission while it was in for normal service, the valve body was on order for 30 days in January. After I delivered the car back to my daughter on January 26, 2026 which was 4 hours away in Northern Virginia the transmission continued to freeze and slam into reverse. The selling dealer advised not to drive it back to Virginia Beach, VA. The car was then dropped off at an Arlington, VA dealer and was there for 9 days. The servicing dealer said they could not duplicate the situation and returned the car after 9 days. My daughter stated that the transmission has continued to act up in reverse with freezing and slaming while trying to reverse in real world settings. The Trailblazer was dropped off for a 3rd time on Saturday, February 21st and since then we have not heard a word from the dealer. I called Chevrolet Customer Service and they assigned a case number to the problem with the transmission. The case number is 89420437 and Sarah at Chevrolet said she would be in contact with my daughter by Sunday, March 1st.
NHTSA complaint #11721070 — an unverified report by a vehicle owner.