2021 Mercedes-Benz C 300 Problems, Complaints & Recalls

Source: NHTSA · Updated Aug 7, 2026 · 14 owner complaints analyzed

Compared with other C 300 years
Far fewer complaints than other years 16th of 19 for complaints
NHTSA crash rating
Not rated

Owners have filed 14 complaints with NHTSA about the 2021 Mercedes-Benz C 300. That ranks 16th out of 19 C 300 model years for complaints. The most reported problem area is engine (8 complaints, 57%), typically at around 87,039 miles. There are 7 safety recalls covering this model year.

Complaints are unverified owner reports and are not adjusted for sales volume.

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Most common 2021 Mercedes-Benz C 300 problems

Complaints grouped by the part of the car owners reported, with the median mileage when the problem happened.

Engine8 · ~87,039 mi
Fuel/propulsion System2
Air Bags1
Back Over Prevention1
Electrical System1
Fuel System, Gasoline1 · ~60,000 mi
Power Train1
Visibility1
Problem areaComplaintsShareMedian milesOwners mention mostTypical repair cost
Engine857%87,039——
Fuel/propulsion System214%———
Air Bags17%———
Back Over Prevention17%———
Electrical System17%———
Fuel System, Gasoline17%60,000——
Power Train17%———
Visibility17%———

One complaint can list several problem areas, so shares can add up to more than 100%.

Complaints by year received

Peak: 2025, with 6 complaints
2022: 1202212023: 1202312024: 3202432025: 6202562026: 320263

n = 14 complaints · Source: NHTSA

2021 Mercedes-Benz C 300 recalls (7)

Tap a recall to see the problem, the risk and the fix.

Fuel system, gasoline:delivery:fuel pumpJun 26, 2023 · NHTSA campaign 23V445000 · 143,551 vehicles

Problem: Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021-2023 C-Class, E-Class, S-Class, CLS, SL, GT, GLC, GLE, GLS, and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle details. The fuel pump may shutdown, which can result in a loss of drive power.

Risk: A loss of drive power can increase the risk of a crash.

Fix: Dealers will replace the fuel pump, free of charge. Owner notification letters were mailed on June 14, 2024. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2023070012.

Electrical system:software; communication: auto crash notificationMay 20, 2022 · NHTSA campaign 22V365000 · 242,722 vehicles

Problem: Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2022 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, AMG GT-Class, C-Class, E-Class, S-Class, SL-Class, GLC-Class, CLS-Class, GLB-Class, and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. An error in the communication module's SIM card software can cause a mobile network connection failure, disabling the emergency call (eCall) system.

Risk: A disabled eCall system would prevent a vehicle occupant from contacting the emergency services call center in an emergency, potentially delaying emergency responders and increasing the risk of injury.

Fix: The communication module software will be updated through an Over-the-Air (OTA) update or by a dealer, free of charge. Owner notification letters were mailed July 8, 2022. Owner notification letters will be mailed in phases, on July 8, 2022, May 17, 2024, July 29, 2024, and September 27, 2024. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's numbers are for this recall is 2022060005 and 2023110006.

Back over prevention:display functionApr 8, 2022 · NHTSA campaign 22V232000 · 126,443 vehicles

Problem: Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2018-2021 CLA-Class, GLE/GLS-Class, A-Class, C-Class, E-Class, E-Class Coupe/Convertible, GLA/GLB-Class, GLC-Class, and CLS-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. The rearview camera may not display the rearview image due to a software error. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 111, "Rear Visibility."

Risk: An inoperable rearview camera display reduces the driver's rear view, increasing the risk of a crash.

Fix: Dealers will update the rearview camera software, free of charge. Owner notification letters were mailed July 15, 2022. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2022060007.

Seats:mid/rear assembly:head restraintMay 28, 2021 · NHTSA campaign 21V406000 · 218 vehicles

Problem: Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021 C300 Cabriolet, C43 AMG Cabriolet, C63 AMG Cabriolet, C63 AMG S Cabriolet, E450 Cabriolet, and E53 AMG Cabriolet vehicles. The rear headrests may be incorrectly mounted to the seatbacks.

Risk: Incorrectly mounted headrests could move or detach from the seat during a crash, increasing the risk of injury.

Fix: Dealers will inspect the rear seatback guide bushings and replace them if necessary, free of charge. Owner notification letters were mailed July 16, 2021. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2021060010.

Seats; seat belts:pretensioner; air bags:sensor:occupant classificationApr 1, 2021 · NHTSA campaign 21V230000 · 8,634 vehicles

Problem: Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021 C-Class, E-Class, E-Class Coupe and Convertible, GLC, CLS, AMG GT 4-door Coupe and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details. A faulty electrical contact within the seat position switch may prevent the driver and passenger air bags and seat belt force limiters from properly activating during a crash.

Risk: Air bags and seat belts that do not perform properly in a crash can increase the risk of injury.

Fix: MBUSA will notify owners, and dealers will replace the seat position switches, free of charge. Owner letters were mailed May 21, 2021. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2021040016.

Communication: auto crash notification; electrical system:softwareFeb 5, 2021 · NHTSA campaign 21V058000 · 1,292,258 vehicles

Problem: Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2016 - 2021 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, GT-Class, C-Class, E-Class, S-Class, CLS-Class, SL-Class, B-Class, GLB-Class, GLC-Class, and G-Class vehicles. Please refer to the Part 573 report for specific vehicle model details. The software design of the communication module may fail to communicate the correct vehicle location for the emergency call system (eCall) in the event of a crash.

Risk: Failure of the eCall system may result in emergency responders being dispatched to the wrong location, increasing the risk of injury following a crash.

Fix: MBUSA will notify owners, and the communication module software will be updated by a dealer, or through an over-the-air (OTA) update, free of charge. The recall began March 12, 2021. Owners may contact MBUSA customer service at 1-877-762-8267. MBUSA's number for this recall is 2021020025.

Seat belts:front:retractorJan 29, 2021 · NHTSA campaign 21V032000 · 24,550 vehicles

Problem: Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2021 C300, 2017-2020 AMG C43, and AMG C63 vehicles. The front seat belts might not fully retract to their stowed position. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 208, "Occupant Crash Protection."

Risk: If the seat belt does not fully retract, the occupant may find the operation of the seat belt inconvenient and not wear it, increasing the risk of injury in the event of a crash.

Fix: MBUSA will notify owners, and dealers will check the retraction function of the front seat belts and adjust the damping foam within the B-pillars, as necessary, free of charge. The recall began February 26, 2021. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2021020010.

To see whether a specific car still has an open recall, enter its VIN on NHTSA's official recall lookup. You can also decode a VIN here.

Recent owner reports

Short excerpts of the latest complaints filed with NHTSA, with personal details removed. Full reports can be searched on NHTSA.gov.

The contact owns a 2021 Mercedes-Benz C 300. The contact stated that while depressing the accelerator pedal, there was a loud knocking sound coming from the engine compartment while accelerating. There were no warning lights illuminated. The vehicle was taken to the dealer to be diagnosed, and it…

Engine · received Aug 7, 2026 · NHTSA complaint 11755408

The contact owns a 2021 Mercedes Benz C. The contact stated that while driving on the highway, the vehicle began to lose power, riding rough. The check engine light illuminated. The vehicle was towed to the dealer where it was diagnosed with a fuel injection failure. The vehicle read diagnostic…

Fuel System, Gasoline · received May 19, 2026 · NHTSA complaint 11738727

I am reporting a safety defect involving the panoramic sunroof on my 2021Mercedes-Benz Coop vehicle. The panoramic sunroof has malfunctioned due to an apparent design or manufacturing defect. The sunroof fails to open / close and makes grinding or popping noises which malfunctioned unexpectedly…

Visibility · received Jan 20, 2026 · NHTSA complaint 11712287

The contact owns a 2021 Mercedes-Benz C300. The contact stated that while driving at an undisclosed speed, the vehicle stalled and failed to exceed 30 MPH, with the check engine warning light illuminated. The vehicle did not require a restart. The contact also stated that while stopped at a traffic…

Engine · received Dec 22, 2025 · NHTSA complaint 11706514

My car had a coolant leak last year a hose broke and I have a 2021. My son’s mercedes sis the same thing on 11/23/2025. I have researched ma y others with this same issue. There should be a recall on that hose or whatever the problem Is.

Fuel/propulsion System · received Nov 25, 2025 · NHTSA complaint 11701496

Other Mercedes-Benz C 300 years

← 2020 C 300 · 2022 C 300 →

See all Mercedes-Benz C 300 problems by year, every Mercedes-Benz model, or the Mercedes-Benz VIN decoder.

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Frequently asked questions

What are the most common problems with the 2021 Mercedes-Benz C 300?

Owners most often report engine, fuel/propulsion system, air bags problems. The top one, engine, accounts for 8 complaints.

Was there a recall on the 2021 Mercedes-Benz C 300?

Yes, 7 safety recalls. Enter your VIN at NHTSA.gov to check whether the repairs were done on your car.

Was the 2021 Mercedes-Benz C 300 a good year?

Complaint data can't fully answer that, because counts aren't adjusted for sales. Compared with other C 300 model years, the 2021 has far fewer complaints than most years. Always get a pre-purchase inspection and check the VIN for open recalls.