2021 Chevrolet Trailblazer power train problems

“As I was driving down the road the check engine light lit on and vehicle went into limp mode which didn’t let me accelerate over 20 miles an hour. This happened in a busy intersection after safely and cautiously moving to the right to avoid any traffic collisions we got it towed. The codes that came up were P0700 and P0796 Transmission failure due to a stuck solenoid. Chevy has Internal bulletin 20-NA-120 regarding these breakdowns. It’s a known problem and one that is dangerous to the public because these incidents can happen anywhere even on busy highways or freeways.”

“My 2021 Trailblazer does not shift into drive properly from park or reverse. When shifting into drive, the engine revs but does not move forward. In some cases, the vehicle also shakes and jolts for several seconds. It is also slow to shift into higher gears at high speeds on the freeway. In cases of quick acceleration, the check engine light comes on and the message "Engine Power Reduced" shows. This has caused potentially dangerous situations where I am not able to accelerate to match the flow of traffic, especially when merging onto the freeway. I have taken the car to both a Chevy dealership and an independent shop, who have both confirmed that there is a "loss of forward gear" and pulled codes P2714 and P0700. I have been told that I most likely need a transmission replacement at only 34,000 miles.”

“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…”

“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…”

“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…”

“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.”