Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2021 Chevrolet Trailblazer owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2021 Chevrolet Trailblazer. The contact stated while driving 65 MPH the contact struck a deer on the front passenger side causing minor damages to the vehicle. No one was injured. The contact was able to stop on the side of the road. The contact smelled a burning odor and noticed that smoke was coming from the floor of the vehicle on the front passenger side near the seat belt assembly. The contact and the passenger were able to exit the vehicle, but after exiting the vehicle burst out in flames. The fire department was able to extinguish the fire. A police report was filed. The vehicle was towed. The manufacturer was not notified of the failure. The failure mileage was 20,000.
The contact owns a 2021 Chevrolet Trailblazer. The contact stated after parking the vehicle and pressing the Push to Start button to turn off the vehicle, an alarm sounded and the message "Shift to Park" was displayed. The contact shifted out of park(P) and slammed the gear shifter into park(P). The contact was then able to park and to turn off the vehicle. The contact stated that the failure recurred intermittently while parking on a level surface. The contact stated that on several occasions the failure required turning off and restarting the vehicle to successfully park the vehicle. Additionally, the contact stated that the failure occurred while attempting to park on an incline. The contact stated that the vehicle was unable to be parked on an incline after several attempts. The dealer was notified of the failure and an appointment was scheduled for diagnostic testing. …
The contact owns a 2021 Chevrolet Trailblazer. The contact stated while parking the vehicle, the gear shifter was shifted into park, however the shift to park warning light illuminated. In addition, the vehicle failed to turn off. The contact made several attempts to shift to park, and the gear shifter failed to function as intended. The contact stated that after several attempts, the shift to park warning light turned off and the contact was able to park and turn off the vehicle. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The dealer was made aware of the failure. The vehicle was scheduled for a diagnostic testing within the next several days. The manufacturer was made aware of the failure but provided no assistance. The contact was advised to contact the NHTSA Hotline to report the failure. The failure mileage was approximately 31,000.
The contact owns a 2021 Chevrolet Trailblazer. The contact stated that while attempting to remove the key from the ignition, the key remained stuck in the ignition cylinder. The contact had to turn off and restart the vehicle several times to be able to remove the key. The contact stated that the failure occurred intermittently. The vehicle was taken to the dealer who sprayed the ignition cylinder to clean the cylinder; however, the failure persisted. The vehicle was returned to the dealer who diagnosed that the shift lock mechanism failed to recognize that the vehicle was in park(P). The shifter assembly was replaced. The manufacturer was informed of the failure and opened a case. The manufacturer referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 20,000.
The contact owns a 2021 Chevrolet Trailblazer. The contact stated that after reversing, the transmission was shifted to drive (D), but the vehicle failed to immediately recognize the selected gear. The check engine warning later illuminated. The vehicle was taken to an independent mechanic, who determined that the under boost, transmission control module, and transmission control solenoid had failed, and there was a loss of communication with the radio and loss of communication with the telematic control module. The mechanic advised the contact to take the vehicle to the dealer for assistance. The vehicle was not repaired. The manufacturer was made aware of the failure and advised the contact to report the failure to the NHTSA Hotline. The failure mileage was approximately 42,000.
The contact owns a 2021 Chevrolet Trail Blazer. The contact stated that after shifting to the park position the message "Shift to Park" was erroneously displayed and the vehicle would not shut off. The contact had to shift multiple times before the transmission switched to the park position and the engine was able to be shut off. The vehicle was taken to the local dealer who diagnosed that the shifter was faulty and needed to be replaced. The vehicle was not yet repaired. The manufacturer was also notified of the failure and confirmed that the part was on backorder. The failure mileage was 16,600.
The contact owns a 2021 Chevrolet Trailblazer. The contact stated that while attempting to park, the vehicle failed to shift into park properly, and the message "Vehicle Not in Park" was displayed. The contact stated that several attempts were needed before the transmission was able to be shifted into park. The vehicle was taken to the dealer, where it was diagnosed and determined that the shifter gear assembly had failed and needed to be replaced. The vehicle was repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 40,000.
The contact owns a 2021 Chevrolet Trailblazer. The contact stated that while the gear shifter was in the park(P), the message "Shift to Park" was displayed. The vehicle was taken to an independent mechanic, who determined that the gear shifter needed to be replaced. The mechanic informed the contact to use the parking brake while parking the vehicle. The contact called the local dealer and was informed that parts were on back order. The vehicle was not diagnosed or repaired. The manufacturer was not contacted. The approximate failure mileage was 16,000.
The contact owns a 2021 Chevrolet Trailblazer. The contact stated that while attempting to park the vehicle, the contact noticed that the gear shifter was inoperable, and the vehicle would not shift into gear properly. There was no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed and determined that the gear shifter had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 40,000.
The contact owns a 2021 Chevrolet Trailblazer. While the contact's wife was attempting to park the vehicle, the shift to park warning light illuminated. The dealer was made aware of the failure; however, the vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The contact was informed of an undisclosed recall; however, the VIN was not under recall. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 79,000.
Transmission complaints in other Trailblazer years
Frequently asked questions
How common are transmission problems on the 2021 Chevrolet Trailblazer?
NHTSA has 41 complaints about the transmission & drivetrain of the 2021 Chevrolet Trailblazer, 21% of the model year's 196 complaints.
Is there a recall for 2021 Chevrolet Trailblazer transmission problems?
No. NHTSA lists no transmission & drivetrain recall for the 2021 Chevrolet Trailblazer, though it has 4 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2021 Chevrolet Trailblazer transmission problems start?
Half of the complaints with a recorded mileage happened before about 33,000 miles, and 40% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 1 fire and 0 injuries to transmission & drivetrain problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.