2021 Mercedes-Benz GLB 250 problems & reliability
29 owner complaints filed with NHTSA for the 2021 Mercedes-Benz GLB 250, alongside 11 safety recall campaigns. Last verified Sep 22, 2026. Complaints are unverified reports submitted by owners to the federal Office of Defects Investigation.
Each complaint is counted once (by NHTSA case number), even when it names several components.
Most reported problems
| Component | Complaints | Share |
|---|---|---|
| Unknown / Other | 10 | 34% |
| Engine | 7 | 24% |
| Electrical System | 4 | 14% |
| Suspension | 4 | 14% |
| Power Train | 3 | 10% |
| Structure | 3 | 10% |
| Back Over Prevention | 2 | 7% |
| Fuel/propulsion System | 2 | 7% |
| Steering | 2 | 7% |
| Wheels | 2 | 7% |
Component groups as classified by NHTSA. A complaint can name more than one component, so shares may sum to more than 100%.
All 16 reported components →Complaints by incident year
What owners report
“The contact owns a 2021 Mercedes-Benz GLB250. The contact stated that the front stationary roof panel detached from the vehicle and shattered. The vehicle was taken to the dealer but was not diagnosed or repaired. The contact became aware of a recall with a similar failure; however, the VIN was not included, and the…”
Structure · filed Aug 12, 2026
“Family and I were driving on the interstate and heard a loud bang (like a shotgun) followed by immediate glass everywhere. The panoramic sunroof exploded. We had to drive 4 hours like this - lucky we didn’t jerk the wheel on the interstate with the noise. Absolutely sickening that this is so prevalent and Mercedes…”
Unknown / Other · filed Apr 29, 2026
“When my car sits in the rain for long periods of time, while driving, it will automatically switch into neutral and give me a "transmission malfunction stop" & "service required do not shift gears visit dealer" sign on the dash. This has happened at least 7 times in 2 years since March 2024. The latest time it…”
Unknown / Other · filed Mar 3, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Technical service bulletins
221 manufacturer communications (TSBs, service campaigns, warranty extensions) are on file with NHTSA for the 2021 Mercedes-Benz GLB 250. The 10 most recent:
Complaint Intermittent shift feel or thud/clunk noise perceived, such as a brief jerk or transmission reaction during certain driving situations. May be most noticeable when transitioning from a coasting condition to…
LI 27.10-P-080851 · Service Bulletin/Repair Instructions · issued Aug 29, 2026
Complaint Temporary no start condition with check engine light and multiple warning messages. When performing a quick test, the following fault code is stored in Y3/14 ‑ Transmission control for 8‑speed dual‑clutch…
LI27.19-P-080869 · Service Bulletin/Repair Instructions · issued Aug 29, 2026
Complaint Customers may report one or more of the following: • Transmission malfunction message • Check engine light illuminated • Shifts into N • Concern disappears after ignition cycle When performing a quick test…
LI27.19-P-080823 · Service Bulletin/Repair Instructions · issued Aug 25, 2026
Complaint Tailgate opens unintentionally. Cause Accidental or unnoticed activation of the button to open the tailgate on the vehicle key. EXAMPLE: when stored in trouser pocket, handbag etc. Remedy As of the 6th…
LI72.20-P-075746 · Service Bulletin/Repair Instructions · issued Aug 24, 2026
Dear Mercedes-Benz Owner: In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA is extending the warranty coverage for…
CL - Tank Leak Detection · Warranty Program/Extension · issued Aug 15, 2026
Complaint 1. General Diagnostic Tips 2. One or More PARK Sensor Activations 3. Red Ring Around Vehicle 4. "Active Parking and Parking Assist Inoperative" on Instrument Cluster 5. Cameras 6. Other Park Topics. Cause…
LI54.65-P-080132 · Service Bulletin/Repair Instructions · issued Aug 12, 2026
Complaint Clanking noise from the area of the speakers in the doors. Cause Under analysis. Remedy To narrow down the cause, first of all remove the door trim. • If the noise continues to occur even with the door trim…
LI82.62-P-078631 · Service Bulletin/Repair Instructions · issued Aug 6, 2026
Complaint Customers may report one or more of the following: • Transmission malfunction message • Check engine light illuminated • Shifts into N • Concern disappears after ignition cycle When performing a quick test…
LI27.19-P-080823 · Service Bulletin/Repair Instructions · issued Aug 4, 2026
This NCU replaces the prior NCU issued on May 15, 2025, and contains additional MY 2023 and MY 2024 vehicles which are highlighted below. In our continuing efforts to ensure the proper performance of Mercedes-Benz…
EW - DMTL · Warranty Program/Extension · issued Jul 31, 2026
Complaint CEL light on with no drivability concerns. Cause Signal timing error. Remedy 167, 465: SW has been released. Update the FSAM to the latest SW version. 290, 118, 243, 247: Software is still in development. This…
LI54.21-P-080326 · Service Bulletin/Repair Instructions · issued Jul 24, 2026
TSBs are repair guidance manufacturers send to dealers — they are not recalls and repairs are not automatically free. Full documents are available on NHTSA’s site.
Safety recalls
The 2021 Mercedes-Benz GLB 250 has 11 NHTSA recall campaigns — recall repairs are free at franchised dealers regardless of the vehicle’s age.
Check whether your specific vehicle is affected
Recall campaigns often cover only certain VIN ranges. Enter your VIN on the official NHTSA site to confirm whether your vehicle is included and whether the repair is still open.
Check VIN on NHTSA →Buying a used 2021 Mercedes-Benz GLB 250?
- · Decode the seller’s VIN with our free VIN decoder to confirm the exact year, engine and trim.
- · Check for unrepaired recalls by VIN on NHTSA’s official lookup — recall repairs are free.