Recall 21V521 affects 138 2018-2019 BMW X3 and X4 vehicles for a passenger-seat air bag sensor defect. Repair is free at any franchised BMW dealer.
BMW is recalling 138 2018-2019 X3 and X4 vehicles because the front passenger seat occupant classification system was assembled incorrectly and can read the seat as empty. That error deactivates the front air bag, so it will not deploy in a crash; BMW dealers will complete the recall repair free of charge.
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What's wrong?
The front passenger seat occupant classification system in the 2018-2019 BMW X3 and X4 is built into the seat foam and wiring. Its job is to tell the air bag control system whether someone is sitting in the front passenger seat. When it reads the seat correctly, the front passenger air bag remains available for a crash that calls for deployment.
On affected vehicles, parts of that seat system were not assembled to BMW supplier specifications. Attachment rings in the seat foam were not secured as intended and can lose proper contact with the electrical cable. In certain seating positions, especially with a smaller front passenger, the system can read the seat as empty even when someone is sitting there. That can turn off the front passenger air bag.
There is no warning sign before failure. The problem is inside the seat foam and occupant sensing system, so an owner cannot confirm it by looking at the seat or by how the seat feels.
Who's affected?
Covers X3 and X4 SUVs from the 2018 and 2019 model years, with the same front passenger occupant classification system tied to the front air bag.
| 2019 BMW X3 | front air bag |
|---|---|
| 2019 BMW X3 | front air bag |
| 2018 BMW X3 | front air bag |
| 2018 BMW X3 | front air bag |
| 2019 BMW X4 | front air bag |
| 2019 BMW X4 | front air bag |
| Units affected | 138 |
| Field incidents | NHTSA has logged no field incidents to date. |
The year and model narrow the scope, but the VIN decides. Check your VIN to confirm whether your specific SUV is included.
What's the safety risk?
If your VIN is included, the front air bag is deactivated and will not deploy in a crash, increasing injury risk for the person in that seat. Until the seat foam and occupant classification system are replaced, avoid using the affected front seat when you can and schedule service soon. Repair is free at any franchised BMW dealer.
What should I do?
- Check your VIN to confirm your 2018-2019 BMW X3 or X4 is included in this recall.
- Contact a franchised BMW dealer to schedule the free seat-foam replacement that fixes the passenger-seat classification fault and keeps the front air bag active when the seat is occupied.
- Bring the recall notice if BMW mailed one. If not, reference recall number 21V521 when you call.
- Ask the BMW dealer whether to limit front passenger use until the repair is complete.
What happens at the repair
At the dealer, a BMW technician replaces the front passenger seat foam, including the occupant classification system built into that seat. The recall repair is free, and BMW covers the related parts and labor. If you already paid out of pocket for this seat foam or occupant classification system repair before the recall notice, BMW's standard reimbursement plan covers documented expenses. Bring receipts or repair documentation to the service desk so the dealer can explain the claim process.
| Reimbursement | Reimbursement available |
|---|
Timeline
| July 8, 2021 | NHTSA published the recall |
|---|---|
| July 8, 2021 | Dealer notification began |
| July 8, 2021 | Dealer notification ended |
| August 30, 2021 | Interim owner notification (was planned for this date) |
| August 30, 2021 | VIN-searchable in NHTSA's database — Check your VIN to see whether this recall applies to your specific vehicle. |
| September 3, 2021 | Owner notification mailed |
Frequently asked questions
What is recall 21V521?
Recall 21V521 covers 138 BMW X3 and X4 vehicles with a front passenger seat occupant classification system that was assembled incorrectly. The seat can be misclassified as empty, which deactivates the front passenger air bag. BMW dealers will replace the seat foam for free.
What should I do if my 2018-2019 BMW X3 or 2019 BMW X4 is on this recall?
Check your VIN to confirm your specific vehicle is included in recall 21V521. If it is, contact a franchised BMW dealer to schedule the seat foam replacement. Reference recall number 21V521 when you call. The repair is free.
Is the recall repair free?
Yes. Federal recall law requires the manufacturer to repair the defect at no cost, and BMW dealers will replace the seat foam, including the occupant classification system, free of charge.
What is the safety risk in recall 21V521?
The front passenger air bag can be deactivated when the seat is incorrectly classified as empty. If a crash occurs, that air bag will not deploy, increasing the risk of injury for the front passenger. BMW's free repair replaces the affected seat foam.
What if I bought my BMW X3 or X4 used?
The free recall repair still applies. Recall eligibility follows the VIN, not the first owner. Check your VIN to confirm whether your specific BMW is included, then call a franchised BMW dealer and reference recall 21V521.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/21V521000 |
|---|---|
| BMW customer service | 1-800-525-7417 |
| NHTSA recall # | 21V521 |
| NHTSA recall # (full) | 21V521000 |
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 →