Recall 21V527 affects 542 2020-2021 Mercedes-Benz vehicles for loose side crash sensor connectors. Repair is free at any franchised Mercedes-Benz dealer.
Mercedes-Benz is recalling 542 2020-2021 E 350, S 450, and Glc 300 vehicles because side crash sensor connectors can come loose and delay air bag and seatbelt activation during a side impact crash. Air bags and seatbelts that do not work as intended can increase injury risk, and the Mercedes-Benz dealer repair is free.
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What's wrong?
The side impact crash sensor on these 2020-2021 Mercedes-Benz vehicles is a pressure sensor tied into the supplemental restraint system, the air bag and seat belt safety system. In a side impact, the sensor helps the vehicle recognize the crash and send the signal that starts side air bag deployment and seat belt tightening.
On affected vehicles, a supplier production deviation left the plug connection on certain pressure sensors outside Mercedes-Benz specifications. The connector housing does not lock to the intended standard. If that connection loosens, the crash signal can be interrupted or delayed, which means the air bags and seat belts do not activate as quickly as designed in a side impact.
When the issue occurs, the instrument cluster displays a specific warning message and the SRS warning lamp turns on. Treat that warning as a sign that the restraint system needs dealer attention.
Who's affected?
Covers sedans, SUVs, coupes, and performance models from 2020 and 2021 that use the same side air bag pressure sensor.
| 2021 Mercedes-Benz E 350 | side air bag |
|---|---|
| 2020 Mercedes-Benz S 450 | side air bag |
| 2020 Mercedes-Benz S 560 | side air bag |
| 2020 Mercedes-Benz Glc 300 | side air bag |
| 2020 Mercedes-Benz AMG GLC63 | side air bag |
| 2020 Mercedes-Benz G 550 | side air bag |
| 2020 Mercedes-Benz AMG G63 | side air bag |
| 2021 Mercedes-Benz E 450 | side air bag |
| 2021 Mercedes-Benz AMG E53 | side air bag |
| 2021 Mercedes-Benz Cls 450 | side air bag |
| 2021 Mercedes-Benz AMG CLS53 | side air bag |
| 2021 Mercedes-Benz AMG GT43 | side air bag |
| 2021 Mercedes-Benz AMG GT53 | side air bag |
| 2021 Mercedes-Benz Glc 300 | side air bag |
| 2021 Mercedes-Benz AMG G63 | side air bag |
| Units affected | 542 |
| Field incidents | NHTSA has logged 1 field incident to date. |
A matching year and model does not guarantee inclusion. Check your VIN to confirm whether your specific vehicle is included.
What's the safety risk?
Air bags and seatbelts that do not work as intended can increase the risk of injury during a crash. If this issue occurs, the instrument cluster shows a warning message and the SRS warning lamp turns on. Treat that warning as a reason to schedule service soon. Repair is free at any franchised Mercedes-Benz dealer.
What should I do?
- Check your VIN to confirm your 2020-2021 Mercedes-Benz E 350, S 450, S 560, Glc 300, AMG GLC63, G 550, AMG G63, E 450, AMG E53, Cls 450, AMG CLS53, AMG GT43, or AMG GT53 is included in this recall.
- Contact a franchised Mercedes-Benz dealer to schedule the free side impact crash sensor inspection and replacement that addresses loose sensor connectors.
- Bring the recall notice if you have it. If not, reference recall number 21V527 when you call.
- Avoid delaying the appointment, since loose side crash sensor connectors can delay air bag and seatbelt activation during a side impact crash.
What happens at the repair
At the dealer, a Mercedes-Benz technician inspects the side impact crash sensor connectors and replaces the side impact crash sensors when the inspection shows they are needed. The recall repair is available now, and parts and labor are free. Repairs already paid before the owner letter are handled through the new vehicle warranty, not through a separate reimbursement program, because the involved vehicles remained under warranty. Ask the service desk how that warranty coverage applies if you have prior repair paperwork.
| Reimbursement | Warranty coverage applies |
|---|
Timeline
| July 12, 2021 | NHTSA published the recall |
|---|---|
| July 16, 2021 | Dealer notification began |
| September 3, 2021 | Owner notification mailed |
| September 10, 2021 | Interim owner notification (was planned for this date) |
Frequently asked questions
What is recall 21V527?
Recall 21V527 covers 542 2020-2021 Mercedes-Benz vehicles with side crash sensor connectors that can come loose. In a side impact crash, delayed air bag and seatbelt activation can increase injury risk. Mercedes-Benz dealers will inspect the side impact crash sensors and replace them as needed for free.
What should I do if my 2020-2021 Mercedes-Benz vehicle is on this recall?
Check your VIN to confirm your specific vehicle is included in recall 21V527. If it is, contact a franchised Mercedes-Benz dealer to schedule the side impact crash sensor inspection. Reference recall number 21V527 or Mercedes-Benz recall number 2021070032/33 when you call.
Is the recall repair free?
Yes. Federal recall law requires the manufacturer to repair the defect at no cost. Mercedes-Benz dealers will inspect the side impact crash sensors and replace them as necessary free of charge.
What is the safety risk?
The safety risk is delayed air bag and seatbelt activation during a side impact crash. Air bags and seatbelts that do not function as intended can increase the risk of injury during a crash. The dealer repair addresses the side impact crash sensor issue for free.
When did Mercedes-Benz notify owners?
Mercedes-Benz mailed owner notification letters on September 3, 2021. If you bought the vehicle used or never received a letter, check your VIN to confirm whether your specific vehicle is included before calling a Mercedes-Benz dealer.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/21V527000 |
|---|---|
| Mercedes-Benz customer service | 1-800-367-6372 |
| NHTSA recall # | 21V527 |
| NHTSA recall # (full) | 21V527000 |
Source documents
-
Download Recall Document (PDF) (PDF) - Download Quarterly Report (PDF)
- Download Misc. Document (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 →