Recall 22V678 affects 6,752 2022 Mercedes-Benz C 300 vehicles for trunk moisture reaching the SAM. Repair is free at any franchised Mercedes-Benz dealer.
Mercedes-Benz is recalling 6,752 2022 C 300 vehicles because moisture in the trunk can leak into the signal acquisition module and cause an electrical short. That short can shut down rear exterior lights or the rearview camera, fold the rear seat unintentionally, and raise crash, injury, or fire risk; Mercedes-Benz dealers will complete the free repair.
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What's wrong?
The rear signal acquisition and actuation module, called the SAM, sits in the trunk area of the 2022 Mercedes-Benz C 300. It is an electrical control unit that receives signals and helps operate rear-compartment electrical functions, so it needs to stay dry and protected from water.
On affected C 300 vehicles, water can drip into the trunk when a wet trunk lid is opened. Because the SAM cover was not installed to the current production specification, that moisture can reach the module. Once water gets inside the electronics, it can create an electrical short circuit in the rear wiring area.
The driver does not get an advance warning before this happens. There is no warning sign before failure, so water in the trunk or unexplained rear electrical problems should be treated as a reason to contact a Mercedes-Benz dealer.
Who's affected?
| 2022 Mercedes-Benz C 300 | wiring |
|---|---|
| Units affected | 6,752 |
| Field incidents | NHTSA has logged 42 field incidents to date. |
A matching year and model does not guarantee inclusion. Check your VIN to confirm whether this recall applies to your specific vehicle.
What's the safety risk?
An electrical short in the SAM can cause rear exterior lighting failure, unintentional rear seat folding, and rearview camera failure, increasing crash or injury risk. It also raises fire risk. There is no warning sign before failure, so schedule the recall repair soon and treat lighting, seat, or camera problems as a reason to stop and call the dealer. Repair is free at any franchised Mercedes-Benz dealer.
What should I do?
- Check your VIN to confirm your 2022 Mercedes-Benz C 300 is included in this recall.
- Contact a franchised Mercedes-Benz dealer to schedule the free SAM cover installation that protects the trunk module from moisture and short circuits.
- Bring the owner letter if you have it. If not, reference recall number 22V678 and Mercedes-Benz recall 2022090011 when you call.
- Keep the trunk dry until the repair is complete, and report rear lighting, rearview camera, or rear seat folding problems when scheduling.
What happens at the repair
At the dealer, a Mercedes-Benz technician installs a protective cover for the signal acquisition module, also called the SAM, in the trunk area. The cover helps keep moisture from reaching the module and causing an electrical short. The recall repair is free, with parts and labor covered. Out-of-pocket repairs already paid are handled through the new vehicle warranty, not through a separate reimbursement program, since the involved vehicles remain under warranty. Ask the service desk how warranty coverage applies if you have prior repair paperwork.
| Reimbursement | Warranty coverage applies |
|---|
Timeline
| September 12, 2022 | NHTSA published the recall |
|---|---|
| September 19, 2022 | Dealer notification began |
| November 11, 2022 | VIN-searchable in NHTSA's database — Check your VIN to see whether this recall applies to your specific vehicle. |
| November 11, 2022 | Interim owner notification (was planned for this date) |
| December 2, 2022 | Owner notification mailed |
Frequently asked questions
What is recall 22V678?
Recall 22V678 covers 6,752 2022 Mercedes-Benz C 300 vehicles with trunk moisture that can leak into the signal acquisition module and cause an electrical short. Mercedes-Benz dealers will install a protective cover for the module free of charge.
What should I do if my 2022 Mercedes-Benz C 300 is on this recall?
Check your VIN to confirm your specific C 300 is included in recall 22V678. If it is, call a franchised Mercedes-Benz dealer and ask for recall 2022090011. The dealer will install the SAM cover free of charge.
Is the recall repair free?
Yes. Federal recall law requires the manufacturer to repair the defect at no cost, and Mercedes-Benz says dealers will install the signal acquisition module cover free of charge at a franchised Mercedes-Benz dealer.
What is the safety risk?
The safety risk is an electrical short in the signal acquisition module. That short can cause rear exterior lighting failure, rearview camera failure, or unintentional rear seat folding, increasing crash or injury risk. It also increases fire risk.
When were owners notified about this recall?
Mercedes-Benz mailed owner notification letters on December 2, 2022. If you bought the vehicle used or never received a letter, check your VIN and reference recall 22V678 or Mercedes-Benz recall number 2022090011 when you call the dealer.
More information
| NHTSA campaign page | nhtsa.gov/vehicle-recalls/22V678000 |
|---|---|
| Mercedes-Benz customer service | 1-800-367-6372 |
| NHTSA recall # | 22V678 |
| NHTSA recall # (full) | 22V678000 |
Source documents
-
Download Recall Document (PDF) (PDF) - Download Quarterly Report (PDF)
- Download Owner Notification Letter (PDF)
- Download Recall Report (PDF)
- Download Owner Notice (PDF)
- Download Recall Investigation Document (PDF) (PDF)
- Download Recall Document (PDF) (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 →