2021 Chevrolet Trailblazer: check engine light

Filed Oct 31, 2026 · Transmission · CA

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.

Filed Oct 20, 2026 · OH

While driving on the interstate on October 17, 2026, my 2021 Chevrolet Trailblazer (1.2L turbo) suddenly lost engine power and would not accelerate, with the check engine light on. I had to coast to the shoulder and have the vehicle towed. The dealer diagnosed a failed turbocharger and a failed timing belt at 110,904 miles — far below GM's own 150,000-mile replacement interval for this belt. A timing belt that fails early can cause sudden, total loss of power at highway speed with no warning. This is a serious safety hazard. An Ohio state trooper had to assist with getting myself and my minor son off the interstate and to a safe location.

Filed Oct 5, 2026 · Transmission · CA

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.

Filed Sep 7, 2026 · Electrical, Engine · IL

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

Filed Sep 3, 2026 · Engine, Fuel system · MD

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.

Filed Jul 11, 2026 · Engine · OH

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!!!

Filed Apr 17, 2026 · Engine · OH

2021 Chevrolet Trailblazer RS (123,000) - Coolant control Valve failure Cooling issues after 20-25 mins of driving. No Check engine lights initially just temperature gauge climbing. After 3 day of trying to drive to and from work. "Engine reduced" and P3075 code. Had it towed to dealership, in which they replaced the water pump. This DID NOT fix the issue. The next two drives (from work, and to work), I had to pull off the road several times to get the car cooled down, and run heater on full blast to drop temperature. Pulling off the road in heavy interstate traffic consistently because of the Coolant Control Valve (25207464 GM). Not to mention me, looking at the temp gauge most of the way to work, versus eyes on the road. The old thermostats would at least give you a temperature code, and not an Engine Coolant Flow Too Low error which leads to water pump being replaced erroneously. Going to plastic control valve next to a hot engine, sounds as good as plastic car jacks for this car. Oh, wait, that happened to me as well, and they recalled it after it broke on me at 2 am in the morning.

Filed Apr 16, 2026 · Engine · TN

While driving down the interstate my 2021 Chevy Trailblazer suddenly flashed "Battery Saver Mode" on the dash and shut off completely. I was able to coast to the side of the road and call for help. This was a MAJOR safety issue as my 4 year old son was riding with me and we could've caused or gotten into a serious accident. There were no previous warnings and no Check Engine Light came on prior to it shutting off--I had been having no issues. The car will not turn on and when attempting to, it makes a screeching noise. I had to get it towed to a local service center who stated my car has "catastrophic engine failure". They advised the issue could be either "timing chain or a dropped valve"--unable to confirm until they take the engine apart completely. They denied issues with the battery or starter and said the engine was completely blown. There was less than 120k miles on it and i kept up with maintenance.

Filed Mar 30, 2026 · Engine · KS

Coolant control valve replacement after 5 years of purchasing the vehicle. Put at risk of over heating while driving, fan stays on after vehicle is turned off. Problem confirmed by 2 dealerships. Check engine light on for a long time, fan over working, staying on after the vehicle is off. The only warnings were the engine light coming on to get inspected and fan over running. 1st came up in December 2025 and it is now almost April 2026 costing me $1600 in repairs!! There are other Chevy models that this looks like it is being covered for but my vehicle is having this issue now and is not being covered?!?? Ever since i bought this vehicle brand new in 2021 it was labeled a lemon and have had nothing but issue after issue after issue!!

Filed Mar 24, 2026 · Brakes, Electrical · RI

When stopped at a red light & the light turns green & I accelerate, the vehicle does not move. It makes a loud noise and jumps. This happens way too many times. There’s also an issue with the brakes, when you press on them, you can hear something grinding, which should not be happening because I bought the car brand new. Also the brakes have always been super squeaky, which is very frustrating because they should not be with a brand new car once again. The engine light goes on and off randomly and doesn’t say anything.

Filed Nov 20, 2025 · Electrical, Engine · MI

The issue is the yellow engine light lit up on the dash of my 2021 Trailblazer in late August of 2025. At the same time, the cluster displayed the message "Engine Power is Reduced". Over the next few weeks my car engine would randomly stall out while I was driving! As you can imagine, this is a very unsafe driving condition. My car stalls and I'm in traffic and have no ability at all to control the vehicle. This happened at least 4 times to me. When I checked the On Board Diagnostic codes on my vehicle the system reported back U060F (Mass Air Flow Sensor). I searched online for this condition with 2021 Trailblazers and found GM Service Bulletin number 22-NA-008, dated March of 2022. This Service Bulletin clearly shows that Chevrolet were well aware of a problem years before it occurred to my vehicle. So, in October I took my car to Bowman Auto Center, explained all of the above to them, and I mentioned the Service Bulletin that I found. Their investigation found that, indeed, the cause of my engine stalling was broken wires to the Mass Air Flow sensor (MAF sensor). Bowman repaired my car and billed me $364.44 as shown on the attached 2-page Repair Order. I tried to make the case with the Bowman Service Department that this should be a warranty repair, and paid by GM. Bowman responded that it was only a Service Bulletin from GM for the issue, and the customer is responsible for payment. I am astonished that repair of this product Design Failure, which results in an unsafe driving condition, would be paid for by the customer! The reason I call it a Design Failure is because NO wiring should break during the life of a vehicle. Engines rock and move, and the Trailblazer design should have compensated for this engine movement by having a sufficient slack loop designed into the wire harness leading to the Mass Air Flow sensor. I filed a case with Chevrolet, number 80982656, but they declined my request for reimbursement $$.

Filed Nov 11, 2025 · Fuel system · SC

2021 Chevrolet Trailblazer check engine code P1467