Is the 2021 Mercedes-Benz C 300 reliable?

There isn't enough NHTSA complaint data on file yet to give this model year a verdict.

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

The most-reported component is engine, accounting for 57% of complaints on file.

How many recalls does the 2021 Mercedes-Benz C 300 have?

7 recalls on file for this model year.

2021 Mercedes-Benz C 300

○ Not enough data

2021 Mercedes-Benz C 300
RENDERED 2026-11-01T12:57:21.035Z

Only 14 complaints on file — too few for a fair verdict.

This verdict reflects complaint volume compared to this model's typical year. Recalls and safety issues below apply regardless of the verdict — always check them.

Only 14 complaints on file — too few for a fair verdict. The data below is complete but unranked.

How is this computed?

Complaints: 14
Recalls: 7
Investigations: 0
Top problem: —

Complaints per year

2021: 14 complaints

View as data table

Year	Complaints
2017	2
2018	98
2019	69
2020	33
2021	14
2022	25
2023	22
2024	11
2025	4
2026	1

Known problem areas

Only 14 complaints on file for this model year — too few to rank by share. Raw counts only, below.

Engine

8 of 14 total reports mention: engine.

Show complaint excerpts

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.

NHTSA ODI report, 2026-08-07

the check Engine light fault code P012D12 The pressure sensor upstream of the turbocharger had a short circuit to positive. Found Kink wire on upstream pressure sensor. A short circuit to positive. Electrical Wire replaced.

NHTSA ODI report, 2024-03-26

First day leasing the vehicle within 6 hours lights malfunction and malfunction warning on dash to seek workshop, vehicle was taken for inspection to original dealer (Mercedes Benz of Bakersfield).

NHTSA ODI report, 2024-01-28

Also filed under Electrical system

Fuel/propulsion system

2 of 14 total reports mention: fuel/propulsion system.

Visibility

1 of 14 total reports mentions: visibility, most commonly citing sun/moon roof assembly.

Power train

1 of 14 total reports mentions: power train.

Fuel system, gasoline

1 of 14 total reports mentions: fuel system, gasoline.

Safety timeline

7 recalls · 0 investigations · oldest first

To check one car, enter its VIN on the NHTSA recall page. Check a VIN →

R

2021-02-26Seat belts21V032000 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.

Remedy: 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.

Check if this car was fixed →
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2021-03-12Communication, electrical system21V058000 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.

Remedy: 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.

Check if this car was fixed →
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2021-05-21Air bags, seat belts, seats21V230000 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.

Remedy: 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.

Check if this car was fixed →
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2021-07-16Seats21V406000 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.

Remedy: 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.

Check if this car was fixed →
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2022-07-08Communication, electrical system22V365000 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.

Remedy: 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.

Check if this car was fixed →
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2022-07-15Back over prevention22V232000 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.

Remedy: 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.

Check if this car was fixed →
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2023-09-29Fuel system, gasoline23V445000 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.

Remedy: 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.

Check if this car was fixed →

Buy-smart checklist

2021 Mercedes-Benz C 300 — pre-purchase inspection

Inspect

Engine: 8 reports on file for this year.
Fuel/propulsion system: 2 reports on file for this year.
Visibility: 1 report on file for this year.

Verify these recalls were completed

Recall 21V032000 · Seat belts
Recall 21V058000 · Communication, electrical system
Recall 21V230000 · Air bags, seat belts, seats
Recall 21V406000 · Seats
Recall 22V365000 · Communication, electrical system
Recall 22V232000 · Back over prevention
Recall 23V445000 · Fuel system, gasoline

FAQ

Is the 2021 Mercedes-Benz C 300 reliable?: There isn't enough NHTSA complaint data on file yet to give this model year a verdict.
What are the most common problems with the 2021 Mercedes-Benz C 300?: The most-reported component is engine, accounting for 57% of complaints on file.
How many recalls does the 2021 Mercedes-Benz C 300 have?: 7 recalls on file for this model year.

Data updated 2026-11-01 · Complaints are unverified owner reports filed with NHTSA, not independently verified defects. Methodology.