Recall 21V639 covers 66 2020 Mercedes-Benz Glb 250 vehicles with faulty restraint software. Free software update at any franchised Mercedes-Benz dealer.
Mercedes-Benz is recalling 66 2020 Glb 250 vehicles because air bag control unit software can fail to activate the front seat belts and front passenger air bag properly during a crash. Air bags and seat belts that do not work as intended increase injury risk, and Mercedes-Benz dealers will update the software free of charge.
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What's wrong?
The airbag control unit in the 2020 Mercedes-Benz Glb 250 is the computer that controls key restraint parts during a crash. It reads crash sensor data and sends timed commands to the front seat belt system and the front passenger air bag. The timing matters because restraints have to work in the right sequence for this vehicle.
On affected vehicles, the control unit received an incorrect parameter data set during production. Those parameters came from a different vehicle model, so the restraint system timing does not match the Glb 250 setup. In a crash, that mismatch means the front seat belts and front passenger air bag do not activate as designed.
There is no warning sign before failure. The issue is inside the control unit software, so the owner is not given an advance warning before a crash exposes the problem.
Who's affected?
| 2020 Mercedes-Benz Glb 250 | air bag system |
|---|---|
| Units affected | 66 |
| Field incidents | NHTSA has logged no field incidents to date. |
Not every 2020 Mercedes-Benz Glb 250 is on the list. Check your VIN to confirm whether your specific SUV is included.
What's the safety risk?
Air bags and seat belts that do not function properly can increase the risk of injury in a crash. There is no advance warning before the issue, so confirm whether your VIN is included and schedule the software update soon. Repair is free at any franchised Mercedes-Benz dealer.
What should I do?
- Check your VIN to confirm your 2020 Mercedes-Benz Glb 250 is included in this recall.
- Contact a franchised Mercedes-Benz dealer to schedule the free air bag control unit software update that helps the front seat belts and front passenger air bag activate properly in a crash.
- Bring the recall notice if Mercedes-Benz mailed one. If not, reference recall number 21V639 when you call.
- Drive with every occupant properly belted until the repair is complete, and avoid delaying the appointment.
What happens at the repair
At the dealer, a Mercedes-Benz technician updates the air bag control unit software so the front seat belts and front passenger air bag activate properly during a crash. Parts and labor are covered under the recall, and the repair is available now. Out of pocket repairs already paid are handled through the new vehicle warranty, not through a separate reimbursement program, because the involved vehicles remain under that warranty. Ask the service desk how warranty coverage applies if you have prior repair paperwork.
| Reimbursement | Warranty coverage applies |
|---|
Timeline
| August 13, 2021 | NHTSA published the recall |
|---|---|
| August 20, 2021 | Dealer notification began |
| September 17, 2021 | Owner notification mailed |
| October 12, 2021 | VIN-searchable in NHTSA's database — Check your VIN to see whether this recall applies to your specific vehicle. |
| October 12, 2021 | Interim owner notification (was planned for this date) |
Frequently asked questions
What is recall 21V639?
Recall 21V639 covers 66 2020 Mercedes-Benz Glb 250 vehicles with air bag control unit software that can fail to activate the front seat belts and front passenger air bag properly in a crash. Mercedes-Benz dealers will update the software for free.
What should I do if my 2020 Mercedes-Benz Glb 250 is on this recall?
Check your VIN to confirm your specific vehicle is included in recall 21V639. If it is, contact a franchised Mercedes-Benz dealer to schedule the air bag control unit software update. Reference recall number 21V639 when you call. The repair is free.
Is the recall repair free?
Yes. Federal recall law requires manufacturers to repair safety defects at no cost. Mercedes-Benz dealers will update the air bag control unit software free of charge, and parts and labor are covered for included vehicles.
What is the safety risk in recall 21V639?
The risk is higher injury exposure in a crash. If the air bag control unit software does not activate the front seat belts and front passenger air bag properly, those restraint systems do not provide the intended crash protection.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/21V639000 |
|---|---|
| Mercedes-Benz customer service | 1-800-367-6372 |
| NHTSA recall # | 21V639 |
| NHTSA recall # (full) | 21V639000 |
Source documents
-
Download Recall Document (PDF) (PDF) - Download Quarterly Report (PDF)
- Download Recall Investigation Document (PDF) (PDF)
- Download Owner Notification Letter (PDF)
- Download Owner Notice (PDF)
- Download Recall Report (PDF)
- Download Recall Acknowledgement (PDF)
This article is generated from NHTSA's primary recall filings and reviewed against the source on May 20, 2026. RecallNotify does not paraphrase NHTSA's consequence language; that text is reproduced as written above. Editorial standards →