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2021 Mercedes-Benz GLB 250 4MATIC Owner Complaints

Reports submitted to NHTSA by owners and drivers, shown in full

Data refreshed

Complaints on fileComplaints are reports submitted to NHTSA by owners and drivers. NHTSA does not verify most reports before publishing them, and a complaint does not establish that a defect exists. Volume is influenced by how many of a vehicle were sold, how long it has been on the road, and how much attention an issue has received.
2
+1 complaint in 30 days
Crash or fire reportedComplaints whose submitter recorded that a crash or a fire occurred. These are the reporter's own answers on the NHTSA form, not verified findings.
0
Filed in the last 12 monthsReports filed with NHTSA in the trailing 365 days. Recent volume reflects attention and vehicle age as much as anything else.
2
Reports on file since Jun 9, 2026

What this page shows

Our database holds 2 NHTSA owner-reported complaints for the 2021 Mercedes-Benz GLB 250 4MATIC. Each one is a report filed by an owner or driver and published by NHTSA without most of them being verified. A complaint is not a confirmed defect, not a recall and not a manufacturer bulletin. Narratives are shown exactly as filed.

Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.

Complaints, most recent first

Showing 1–2 of 2

EngineFuel system
Filed Jul 30, 2026

As I was driving down road car began to lose power, check engine light came on and car went into limp mode. Car was towed to nearest repair shop where analysis was made. I was advised to take to dealership for repair. Advised that there was a service campaign issued by the manufacturer on GLB class with M260 motors. See attached report. Took car to MB dealer and informed that an update to the ECU was needed but not available at this time. See attached report. Returned home to PA called Mercedes main office Customer service to check warranty and coverage yes it covered once dealer verifies codes. Called NHTSA to report where they verified that the manufacturer had agreed to repair the issue and extended the waranty instead of doing a recall. Was advised to file report online because the dealership is now demanding payment to do the software update. Which was already verified see attached. A rail pressure sensor is a core engine management component that measures fuel pressure in the fuel rail, sends real-time data to the engine computer, and helps regulate fuel delivery. Rail Pressure Sensor system Fault code P019185 Stores in MED41 control unit. Available for Inspection

NHTSA ID
11753817
Incident
Jun 16, 2026
ElectricalEngine
Filed Jun 9, 2026

While driving on the highway at 70mph my transmission malfunction warning light illuminated in red and my vehicle went into limp mode, creating a life threatening safety defect at highway speeds. I immediately took the vehicle to Mercedes Benz of Pittsburgh. The dealer's own diagnostic tech notes stated 'software is in preparation for concern' confirming this is a known safety defect on Mercedes' end. The dealer was unable to replicate the concern or produce stored fault codes but acknowledged software is actively being developed to address this issue. I contacted MBUSA who confirmed the only escalation path available is a buyback, meaning Mercedes cannot provide a timeline for the software fix. I am currently unable to safely drive my vehicle and am requesting this be investigated as a potential safety defect that may affect other 2021 Mercedes GLB 250 owners.

NHTSA ID
11742901
Incident
May 22, 2026

Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.

Data sources

Data on this page last refreshed .