vehicle signal
U.S. public vehicle records

2021 Mercedes-Benz C 300: complaints, problems and recalls

Explore the records behind recurring owner reports.

Key facts

14 owner complaints analyzed

7 distinct recall campaigns

86,078 mi median reported failure mileage

Scope: 2021 model year. Data snapshot: . 3 complaints include usable failure mileage.

Owner-reported patterns

Most common problems

Engine is the most frequently named component, appearing in 8 of 14 complaints (57.1%). A complaint can name multiple components.

Recurring terms in complaint narratives
TopicMatching reportsShare of complaints
Electrical and battery issues321.4%
Transmission and shifting17.1%
Engine operation17.1%

Topic matches use published keyword rules. They describe mentions, including negations or comparisons, and do not confirm a diagnosis. Read the matching rules.

Component breakdown

Number of unique complaints naming each component. Top eight shown.

Engine
8
Fuel/Propulsion System
2
Air Bags
1
Back Over Prevention: Sensing System: Camera
1
Electrical System
1
Fuel System, Gasoline
1
Power Train
1
Visibility:Sun/Moon Roof Assembly
1
Component breakdown data
CategoryCount
Engine8
Fuel/Propulsion System2
Air Bags1
Back Over Prevention: Sensing System: Camera1
Electrical System1
Fuel System, Gasoline1
Power Train1
Visibility:Sun/Moon Roof Assembly1

Engine: 8; Fuel/Propulsion System: 2; Air Bags: 1; Back Over Prevention: Sensing System: Camera: 1; Electrical System: 1; Fuel System, Gasoline: 1; Power Train: 1; Visibility:Sun/Moon Roof Assembly: 1

Reported problems by failure mileage

Complaint counts in mileage bands. These are not failure rates per vehicle or mile.

Under 25,000
0
25,000 to 49,999
0
50,000 to 74,999
1
75,000 to 99,999
2
100,000 to 149,999
0
150,000 and above
0
Reported problems by failure mileage data
CategoryCount
Under 25,0000
25,000 to 49,9990
50,000 to 74,9991
75,000 to 99,9992
100,000 to 149,9990
150,000 and above0

Under 25,000: 0; 25,000 to 49,999: 0; 50,000 to 74,999: 1; 75,000 to 99,999: 2; 100,000 to 149,999: 0; 150,000 and above: 0

75,000 to 99,999 miles has the most reports with usable mileage (2). 11 complaints have missing, zero or invalid mileage.

Complaints over time

Year the complaint was filed, not the vehicle model year or incident year. The snapshot year is partial.

2022
1
2023
1
2024
3
2025
6
2026
3
Complaints over time data
CategoryCount
20221
20231
20243
20256
20263

2022: 1; 2023: 1; 2024: 3; 2025: 6; 2026: 3

Pattern summary

Engine leads the component reports. Electrical and battery issues appears in 3 complaint narratives. Transmission and shifting appears in 1 complaint narratives. Engine operation appears in 1 complaint narratives. Use these patterns to inspect individual reports and prepare questions for a mechanic.

Calculated from recorded counts. An AI narrative has not been published for this selection.

Examples from the source records

Examples provide context, not a representative sample or a verified diagnosis.

Owner report 11453645 · 2022-02-23 (February 23, 2022)

The contact owns a 2021 Mercedes-Benz C300. The contact stated while driving at an unknown speed, there was a burning odor inside the vehicle. The contact stated the passenger side air bags was enabled warning light was illuminated. The contact also stated the vehicle made an abnormal noise. The contact took the vehicle to the local dealer but was unable to duplicate the failure. The manufacturer had not been informed of the failure. The failure mileage was unknown.

Owner-reported narrative. Look up ODI 11453645 at NHTSA ↗

Owner report 11525102 · 2023-06-02 (June 2, 2023)

Piston Connecting Rod broke and left the engine making holes in both sides of the block; Mercedes Benz rejected any responsibility because the car has a branded title. Currently a new engine (brand new) is being installed, my concern is that what will happen if the new engine has the same defective part and blew up again.

Owner-reported narrative. Look up ODI 11525102 at NHTSA ↗

Owner report 11568290 · 2024-01-28 (January 28, 2024)

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). During inspection I added additional concerning complaints about passenger door not closing correctly/wind noise seeping through when closed, and hood not closing promptly. One month into leasing vehicle passenger window malfunction, took for inspection and repair to original dealer (MBofBakersfield). Concerned with caution for me, my family, and fr…

Owner-reported narrative. Look up ODI 11568290 at NHTSA ↗

Owner report 11579561 · 2024-03-26 (March 26, 2024)

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.

Owner-reported narrative. Look up ODI 11579561 at NHTSA ↗

Owner report 11623522 · 2024-11-04 (November 4, 2024)

Rearview camera not displaying any image when transmission is put in reverse.

Owner-reported narrative. Look up ODI 11623522 at NHTSA ↗

Owner report 11643229 · 2025-02-17 (February 17, 2025)

Cylinder head needed to be replaced on the M264 engine at 35,000 miles. The replacement part is also known to be defective for the same reasons. This is a common defect known to the manufacturer and they have not issued a recall. My concern is that of a roadside breakdown that would endanger my wife and myself. Thank you for your consideration.

Owner-reported narrative. Look up ODI 11643229 at NHTSA ↗

Owner report 11678865 · 2025-08-06 (August 6, 2025)

My C300 only had about 42,000 miles and was less than 5 years old. Just after the factory warranty expired, the engine was running rough and hot, and "check engine" light illuminated. My local garage quickly diagnosed the problem as a failed cylinder head, stated that it is common with Mercedes 4-cylinder engines from about 2017, and said Mercedes may cover it since it is a "known problem" and shouldn't happen with that mileage. I was charged $7,860 by my local Mercedes dealer, and despite multiple contacts with MercedezUSA, they refuse to ack…

Owner-reported narrative. Look up ODI 11678865 at NHTSA ↗

Owner report 11691568 · 2025-10-06 (October 6, 2025)

While driving car on Sunday 10/5, it suddenly failed to respond to gas pedal pressure. The car stopped accelerating and rather slowed to 15 MPH, almost causing a car from behind to hit me in the rear side.

Owner-reported narrative. Look up ODI 11691568 at NHTSA ↗

Recall history

7 distinct campaigns affect this selection. Announcement dates below are different from vehicle model years. A campaign may cover multiple years.

21V032000 · Seat Belts:Front:Retractor

Reported: 2021-01-29 (January 29, 2021)

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."

Consequence: 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.

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. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2021020010.

NHTSA campaign record ↗
21V058000 · Communication: Auto Crash Notification | Electrical System:Software

Reported: 2021-02-05 (February 5, 2021)

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.

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

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. MBUSA's number for this recall is 2021020025.

NHTSA campaign record ↗
21V230000 · Seat Belts:Pretensioner | Air Bags:Sensor:Occupant Classification | Seats

Reported: 2021-04-01 (April 1, 2021)

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.

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

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.

NHTSA campaign record ↗
21V406000 · Seats:Mid/Rear Assembly:Head Restraint

Reported: 2021-05-28 (May 28, 2021)

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.

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

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. MBUSA's number for this recall is 2021060010.

NHTSA campaign record ↗
22V232000 · Back Over Prevention:Display Function

Reported: 2022-04-08 (April 8, 2022)

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."

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

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.

NHTSA campaign record ↗
22V365000 · Communication: Auto Crash Notification | Electrical System:Software

Reported: 2022-05-20 (May 20, 2022)

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.

Consequence: 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.

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. 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.

NHTSA campaign record ↗
23V445000 · Fuel System, Gasoline:Delivery:Fuel Pump

Reported: 2023-06-26 (June 26, 2023)

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.

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

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.

NHTSA campaign record ↗