2021 Chevrolet Trailblazer problems

POWER TRAIN

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.

ELECTRICAL SYSTEM

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.

ENGINE

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.

POWER TRAIN

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.

ENGINE

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.

FUEL/PROPULSION SYSTEM

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.

ELECTRICAL SYSTEM

Shifter

NHTSA complaint #11757775 — an unverified report by a vehicle owner.

ENGINE

My timing belt snapped prematurely, causing a total loss of engine power while driving on the highway, which is a severe safety hazard

NHTSA complaint #11754543 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

I am submitting this report regarding my 2021 Chevrolet Trailblazer because it has been experiencing the "Shift to Park" issue described in the GM bulletin 19-NA-206. Even when the vehicle is shifted into Park, it intermittently displays a "Shift to Park" message and does not recognize that the transmission is in Park. This issue has been ongoing and has not resolved despite normal use of the vehicle. It is frustrating to deal with on a regular basis, and it appears to be the same condition addressed by GM in Technical Service Bulletin 19-NA-206 that is available to view on the NHTSA website. I believe the NHTSA should push General Motors to issue a recall for this problem rather than relying on a Technical Service Bulletin. The issue appears to affect many GM vehicles, and owners should not have to bear the burden of repeated repairs or diagnosis for a known defect. I respectfully request that the NHTSA investigate this issue further and require GM to provide a permanent remedy through a recall.

NHTSA complaint #11754013 — an unverified report by a vehicle owner.

POWER TRAIN

"shift to park" issue on a 21 traiblazer causing your car to not being able to shutdown entirely meanwhile the shift is perfectly on Park.

NHTSA complaint #11753767 — an unverified report by a vehicle owner.

UNKNOWN OR OTHER

Vehicle displays Shift to Park when vehicle is in park & you push the ignition button & audible chime occurs. Apparently this is a known issue for Chevrolet Trailblazers & Buick Encore GX vehicles model year 2021 & newer. You have to either wiggle the gear shifter several times & depress/wiggle the shift lever button in order to turn off the vehicle. Sometimes it takes 5 minutes to get it to work.

NHTSA complaint #11752759 — an unverified report by a vehicle owner.

POWER TRAIN

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.

ENGINE

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.

ENGINE

Reduced engine powers caused by turbo charger underboost, at 91200 miles.

NHTSA complaint #11751316 — an unverified report by a vehicle owner.

POWER TRAIN

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.

UNKNOWN OR OTHER

When putting the vehicle in park an error displays, SHIFT TO PARK, and the vehicle does not turn off completely and will ding although you’ve put it in PARK. This has been happening for well over a year and the dealership says it’s a known issue but not a recall. There are times it’s taken up to 25 mins that I’ve had to sit in the vehicle to get the vehicle to turn off by wiggling the shifter or just putting it in drive and back into park, hitting the shifter button, etc. I’ve had to let the battery die in the very beginning because I panicked when it happened and had to get into work. My son has been late to class when he uses the vehicle to drive to school. It’s been such an inconvenience and a safety issue because the vehicle doesn’t turn off and won’t lock and who knows if it’s really securely engaged in the park position or not.

NHTSA complaint #11750520 — an unverified report by a vehicle owner.

UNKNOWN OR OTHER

The infotainment system which controls the radio,backup camera, onstart,and other safety components stopped working i took it to a gm certified dealership and it has just been all bad from there. gm has horrible customer service and so does the gm certified shop in michigan city i took my truck in that I only had for 11 months because the infotainment center went of paid for two diagnostic tests they still couldn't] find the issue and now they they're changing me 1,037.76 for a radio which they dont even know if it's going to fix the problem which if it doesn't then I have to pay more money for another diagnostic test and more parts and because I got mad and said I'm paying for a guessing game the dealership told gm that because I had some aftermarket equipment in my vehicle that that caused the issue bullshit the stuff never got plugged into anything at that point the day of my appointment with the audio shop the screen went black with no sound they're all full of shit and didn't want to take responsibility for the widely known issue with the telemedic system

NHTSA complaint #11749755 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

The infotainment system which controls the radio,backup camera, onstart,and other safety components stopped working i took it to a gm certified dealership and it has just been all bad from there. gm has horrible customer service and so does the gm certified shop in michigan city i took my truck in that I only had for 11 months because the infotainment center went of paid for two diagnostic tests they still couldn't] find the issue and now they they're changing me 1,037.76 for a radio which they dont even know if it's going to fix the problem which if it doesn't then I have to pay more money for another diagnostic test and more parts and because I got mad and said I'm paying for a guessing game the dealership told gm that because I had some aftermarket equipment in my vehicle that that caused the issue bullshit the stuff never got plugged into anything at that point the day of my appointment with the audio shop the screen went black with no sound they're all full of shit and didn't want to take responsibility for the widely known issue with the telemedic system

NHTSA complaint #11749755 — an unverified report by a vehicle owner.

ENGINE

car was driving fine, went up a hill then check engine light came on with warning that stated "reduced engine power." drove it approx 8 min to home. parked in garage. Next morning, took to Firestone Complete Autocare as that was the first place available. Just got a call that the whole turbo assembly needs to be replace costing almost $2000 and will be without a car for about a week. 5 year warranty expired 3 months ago and there is less than 47,000 miles on it. It is currently at the shop so I don't have a bill yet, but they told us how much when they told us what was wrong with it. This is unacceptable! Reading about and hearing about this complaint all over the internet!!!

NHTSA complaint #11749711 — an unverified report by a vehicle owner.

UNKNOWN OR OTHER

The shift to park is defective on mine and many other GM vehicles. I had it previously repaired under manufacturer warranty and then again in just over 16,000 miles driven which fell outside of the manufacturer warranty. I had to pay out of pocket for the repairs and GM refused to reimburse me for the repairs. GM has a service bulletin recognizing the defective part and still refused reimbursement. The shift to park causes the vehicle to not recognize the vehicle is in park preventing it from shutting off. This causes the battery to drain and need replacement as well. I have now had the shift to park and battery replaced twice in under 45,000 miles. The service advisor for Seminole Chevrolet advised this part should last minimum of 100,000 miles and it is a known issue. This causes a major safety concern as the vehicle doesn't shut off and could cause someone to be stranded anywhere. It is concerning that a major vehicle manufacturer is continuing to manufacture and use known defective parts. My vehicle has been inspected and repaired both times at Seminole Chevrolet in Sanford, FL. I have also contacted the Executive Resolution team at GM with no resolution. The shift to park and low battery illuminates on the dashboard before the vehicle completely shuts down due to the battery failing caused by the shift to park defect.

NHTSA complaint #11749121 — an unverified report by a vehicle owner.

UNKNOWN OR OTHER

Due to the Front view camera module going bad, I have no access my ADAS.

NHTSA complaint #11748172 — an unverified report by a vehicle owner.

UNKNOWN OR OTHER

Shift assembly kit, it is available. Dealership has to order part for inspection. Still passed inspection. Possible unintended rollaway accidents. Not being able to lock the vehicle as well. Yes, it’s been confirmed. There’s also so many class action lawsuits against GM about this matter. Why isn’t there a recall already?! Getting the “shift to park” message in my vehicle for the 2nd time now in less than 4 years. The shift assembly kit was replaced back in December 2022. Apparently it needs to be replaced again because of a switch.

NHTSA complaint #11747213 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

My 2021 chevy trailblazer rs is experiencing issues with the infotainment system and the onstar module they have stopped working and I have no backup camera and this issue is a safety concern to me and anyone who rides with me i have contacted both gm and onstar and got nowhere with them after I had a diagnostic test done on 6/18/26 they recommended replacement of the whole system

NHTSA complaint #11745155 — an unverified report by a vehicle owner.

UNKNOWN OR OTHER

Dealership Linwood inspected vehicle and certified power and ground module has internal fault-faulty front camera module.

NHTSA complaint #11742562 — an unverified report by a vehicle owner.

FORWARD COLLISION AVOIDANCE: WARNINGS

Dealership Linwood inspected vehicle and certified power and ground module has internal fault-faulty front camera module.

NHTSA complaint #11742562 — an unverified report by a vehicle owner.