Recall 21V789 affects 1,311 2021 Mercedes-Benz S 500 and S 580 vehicles for passenger air bag software deactivation. Free repair at any franchised Mercedes-Benz dealer.
Mercedes-Benz is recalling 1,311 2021 S 500 and S 580 vehicles because air bag control unit software can deactivate the occupant recognition control unit, turning off the front passenger air bag. A deactivated passenger air bag increases the risk of injury during a crash, and Mercedes-Benz dealers will complete the recall repair free of charge.
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What's wrong?
The air bag control unit software in the 2021 Mercedes-Benz S 500 and S 580 is part of the supplemental restraint system. It works with the front passenger occupant recognition unit, which reads the passenger seat and helps the vehicle decide whether the front passenger air bag should be active.
In affected vehicles, a batch of air bag control units contains software that does not meet Mercedes-Benz specifications because of a development-process deviation. That software can deactivate the occupant recognition unit for the front passenger seat. If that happens, the vehicle treats the front passenger air bag as off, so the passenger loses that layer of crash protection.
There is no warning sign before the issue occurs. Once it occurs, the driver sees the message "Restraint System Malfunction Service Required," the supplemental restraint system warning lamp, and a "Passenger Airbag Off" status display in the instrument cluster.
Who's affected?
The S 500 and S 580 share the same air bag software recall, split between the front passenger occupant classification sensor and the air bag control software.
| 2021 Mercedes-Benz S 500 | front air bag |
|---|---|
| 2021 Mercedes-Benz S 500 | air bag system |
| 2021 Mercedes-Benz S 580 | front air bag |
| 2021 Mercedes-Benz S 580 | air bag system |
| Units affected | 1,311 |
| Field incidents | NHTSA has logged no field incidents to date. |
A matching year and model does not guarantee inclusion. Check your VIN to confirm whether your specific sedan is included.
What's the safety risk?
If the passenger air bag is deactivated, the front passenger has less crash protection and faces a higher risk of injury in a crash. The issue starts without advance warning. When it happens, the cluster shows "Restraint System Malfunction Service Required," the warning lamp, and a "Passenger Airbag Off" status. Schedule the software update soon. Repair is free at any franchised Mercedes-Benz dealer.
What should I do?
- Check your VIN to confirm your 2021 Mercedes-Benz S 500 or S 580 is included in this recall.
- Contact a franchised Mercedes-Benz dealer to schedule the free air bag control unit software update that fixes the front passenger air bag deactivation issue.
- Bring the recall notice if Mercedes-Benz mailed one, or reference recall number 21V789 when you call.
- Call Mercedes-Benz customer service at 1-800-367-6372 with questions about recall number 21V789.
- Avoid carrying a front passenger until the software update is complete.
What happens at the repair
At the dealer, a Mercedes-Benz technician updates the air bag control unit software so the occupant recognition control unit does not deactivate the front passenger air bag. The recall repair is free, with the work covered by Mercedes-Benz. Reimbursement is handled through the existing new vehicle warranty, not through a separate reimbursement program before the recall notice, because the involved vehicles were not previously subject to this condition and remain under warranty. Ask the service desk how warranty coverage applies if you have prior repair paperwork.
| Reimbursement | Warranty coverage applies |
|---|
Timeline
| October 11, 2021 | NHTSA published the recall |
|---|---|
| October 15, 2021 | Dealer notification began |
| December 1, 2021 | Owner notification mailed |
| December 3, 2021 | Interim owner notification (was planned for this date) |
Frequently asked questions
What is recall 21V789?
Recall 21V789 covers 1,311 2021 Mercedes-Benz S 500 and S 580 vehicles with air bag control unit software that can deactivate the front passenger occupant recognition control unit. That can leave the front passenger air bag deactivated. Mercedes-Benz dealers will update the software for free.
What should I do if my 2021 Mercedes-Benz S 500 or S 580 is on this recall?
Check your VIN to confirm your specific vehicle is included in recall 21V789. If it is, contact a franchised Mercedes-Benz dealer to schedule the air bag control unit software update. Reference recall number 2021100010 or 21V789 when you call. The repair is free.
Is the recall repair free?
Yes. Federal recall law requires the defect repair at no cost, and Mercedes-Benz will update the air bag control unit software free of charge at any franchised Mercedes-Benz dealer. Parts and labor are covered for vehicles included in recall 21V789.
What is the safety risk?
The risk is that the front passenger air bag can be deactivated during a crash. A deactivated passenger air bag increases the risk of injury for the person in that seat. If your VIN is included, schedule the free software update with a Mercedes-Benz dealer.
When were owners notified about recall 21V789?
Mercedes-Benz mailed owner notification letters on December 1, 2021. If you bought the vehicle used or never received a letter, the VIN still decides whether the recall applies. Check your VIN, then contact a franchised Mercedes-Benz dealer if your vehicle is included.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/21V789000 |
|---|---|
| Mercedes-Benz customer service | 1-800-367-6372 |
| NHTSA recall # | 21V789 |
| NHTSA recall # (full) | 21V789000 |
Source documents
-
Download Recall Document (PDF) (PDF) - Download Quarterly Report (PDF)
- Download Recall Report (PDF)
- Download Recall Investigation Document (PDF) (PDF)
- Download Owner Notification Letter (PDF)
- Download Owner Notice (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 →