2021 Chevrolet Trailblazer Other or unknown Problems
- Complaints
- 59about this part
- Share
- 30%of 198 total for the year
- Median mileage
- 2,000miles
- Trend
- RisingComplaints filed in the last 3 full calendar years are at least 25% higher than in the 3 years before.
NHTSA recorded 59 complaints about the other or unknown of the 2021 Chevrolet Trailblazer, 30% of the 198 complaints for this model year. Where a mileage was given, the median is 2,000 miles.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“Two times I have heard a loud pop noise coming through my stereo speakers. I noticed it when applying the brakes. I went on a Trailblazer forum and a few others had reported the same thing. I heard the pop today when I was pulling into a parking spot and applying the brakes.”
NHTSA complaint #11403605, filed 2021-03, 2,000 miles“Shift to park error. I put the car in park but it tell I get a notice to shift the car in park when it’s already in park. Beeps and continues to tell me to shift my car in park when it’s in park. Turn off the car get out and close the door and the notice and beeping continues while the car is off and in park. Been happening since I bought it.”
NHTSA complaint #11690257, filed 2025-09“I needed to have my muffler welded in November to pass inspection. I was told I would likely need the entire thing replaced in a year. I now hear another exhaust leak, and I’m preparing for a hefty car travel and have to deal with trying to get it fixed in 10 days time. This is ridiculous on a 5 year old car that I have only had two year. This needs to be a recall, insane to have to pay for a whole replacement.”
NHTSA complaint #11738187, filed 2026-05“Found standing water in spare tire well. Back seat constantly wet, growing mold. The whole back area is moldy, mold under driver seat. My back passenger door seal has mold and water. Seat belts in back, MOLD. I had to wear a mask just to drive to the store. The mold turning black the day I took it to a shop for a water test. It's been two days and I still haven't heard anything about the water test.”
NHTSA complaint #11636360, filed 2025-01“While driving on the highway, I heard a loud pop that made me flinch and swerve. After parking I noticed the glass in the sunroof had exploded upward like a volcano, leaving a large hole. Fortunately the shade was closed, or glass would have come into the car while I was driving.”
NHTSA complaint #11726763, filed 2026-03Related service bulletins
- 11037555Sep 26, 2026This PI provides Diagnostics tips on how the LIN bus works and how to diagnosis it.
- 11037253Sep 4, 2026This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
- 11037252Sep 4, 2026This Preliminary Information provides the dealer information of the location of the rear seat child anchors.
- 11036693Aug 28, 2026This Preliminary Information provides a diagnostic tip for diagnosing an issue with Cruise Control, Adaptive Cruise and Lane Keep Assist Turns Off or Inoperative.
- 11036392Aug 20, 2026This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues
- 11035696Jul 31, 2026This Preliminary information communicates to the techicians a diagnostic tip if a customer has a complaint of a whistle/wind noise at highway speeds.
- 11035349Jul 23, 2026This Preliminary information communicates to the technician the direction needed when encountering an issue with switching between adaptive cruise control and regular cruise…
- 11035340Jul 21, 2026PI to help diagnose A/C concern
- 11034769Jun 23, 2026This Preliminary information communicates an issue with an OTA pending message still displayed after an OTA event and how to reset/clear the message.
- 11033723Jun 3, 2026PIP6032B provides diagnostic direction for dealers when encountering transmission leaks
Other or unknown: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2026 | 4 | 33% |
| 2025 | 7 | 27% |
| 2024 | 6 | 17% |
| 2023 | 15 | 20% |
| 2022 | 36 | 32% |
| 2021 | 59 | 30% |
| 2009 | 1 | 4% |
| 2008 | 9 | 5% |
| 2007 | 16 | 2% |
| 2006 | 23 | 2% |
| 2005 | 32 | 2% |
| 2004 | 21 | 2% |
| 2003 | 19 | 2% |
| 2002 | 36 | 3% |
| 2001 | 2 | 10% |
Other parts of the 2021 Chevrolet Trailblazer
41 complaintsTransmission and drivetrain
41 complaintsEngine
39 complaintsBrakes
32 complaintsFuel system
18 complaintsForward collision avoidance
11 complaintsBody and structure
8 complaintsSteering
6 complaintsVehicle speed control
5 complaintsVisibility (wipers, defrost, mirrors)
4 complaintsAir bags
3 complaintsBack-over prevention (rear camera)
3 complaints
← All problems reported for the 2021 Chevrolet Trailblazer
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 29, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology