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What 125 owners told NHTSA about the 2018 Mercedes-benz C-class

These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.

All (125)Crash / fire / injury (5)Engine (39)Body & structure (15)Steering (13)Electrical system (12)Fuel system (10)Transmission & drivetrain (6)Airbags (5)Communication (5)Tires (5)Wheels (5)

5 of 125 complaints match · Communication · clear filters

Mar 10, 2023Electrical systemCommunication

The contact owns a 2018 Mercedes-Benz C300. The contact stated that after starting the vehicle, the S.O.S. Not Active message displayed. The contact was concerned that in the event of an emergency, the emergency services function would be inoperable. The vehicle had previously been serviced under NHTSA Campaign Number: 21V058000 (Electrical System, Communication) however, the failure recurred. The dealer was made aware of the failure; however, the vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 85,000.

NHTSA ODI 11511208

Jul 21, 2022Electrical systemCommunication

The contact owns a 2018 Mercedes-Benz C300. The contact stated that the SOS warning light was illuminated. Upon testing the SOS system, the contact stated that the system failed to operate as needed. The contact then received notification of NHTSA Campaign Number: 22V365000 (Electrical System, Communication). The vehicle was taken to the dealer for service, however, the failure persisted. The vehicle was taken back to the dealer on multiple occasion for multiple repairs related to the failure. Recently, the contact was informed that the Hermes control unit was defective. The manufacturer was notified of the failure and the contact was informed that the repair cost was not covered. The vehicle was not repaired. The failure mileage was unknown.

NHTSA ODI 11475159

May 27, 2021Electrical systemCommunication

The contact owns a 2018 Mercedes-Benz C300 4matic. The contact received notification of NHTSA Campaign Number: 21V058000 (Communication, Electrical System) however, the part to do the recall repair was not yet available. The local dealer was contacted and stated that the equipment needed to perform the repair was not available. The manufacturer was contacted and informed the contact that the repair was an over-the-air software update. The vehicle was not yet repaired, nor was there any way to confirm that the software update was completed. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact stated that the START/STOP feature failed to perform as designed. The rear windows failed to raise and lower as needed. The contact took the vehicle to the dealer to be repaired. The exact repairs were unknown. The approximate failure mileage was 49,000.

NHTSA ODI 11418776

May 24, 2021Electrical systemCommunication

The contact owns a 2018 Mercedes-Benz C43 AMG. The contact received notification of NHTSA Campaign Number: 21V058000 (Communication, Electrical System) however, the part to do the recall repair was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was notified of the issue. The contact had not experienced a failure. Parts distribution disconnect.

NHTSA ODI 11418320

Apr 23, 2021Electrical systemCommunication

TL* THE CONTACT OWNS A 2018 MERCEDES-BENZ C300. THE CONTACT RECEIVED NOTIFICATION OF NHTSA CAMPAIGN NUMBER: 21V058000 (COMMUNICATION, ELECTRICAL SYSTEM) HOWEVER, THE PART TO DO THE RECALL REPAIR WAS NOT YET AVAILABLE. THE CONTACT STATED THAT MERCEDES-BENZ OF SAN FRANCISCO (LOCATED AT 500 8TH ST, SAN FRANCISCO, CA 94103, (415) 673-2000) EXCEEDED A REASONABLE AMOUNT OF TIME FOR THE RECALL REPAIR. THE MANUFACTURER WAS NOTIFIED OF THE ISSUE. THE CONTACT HAD NOT EXPERIENCED A FAILURE. PARTS DISTRIBUTION DISCONNECT. ## VIN PASSED ## MERCEDES-BENZ 2018 C300A ##*DT

NHTSA ODI 11413611

Working with the data? Download all 125 complaints as CSV · fetched from NHTSA July 14, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2018 Mercedes-benz C-class verdict →