AI DamageMercedes-Benz C 300 4matic: problems, complaints, bulletins
Summary for the Mercedes-Benz C 300 4matic across 8 model years: 18 owner complaints and 214 NHTSA service bulletins, plus repair videos. Pick a year for details.
Model years
What fails most often
- 1 Structure 22% of all complaints
- 2 Electrical system 17% of all complaints
- 3 Engine 17% of all complaints
- 4 Suspension 17% of all complaints
- 5 Exterior lighting 11% of all complaints
- 6 Air bags 11% of all complaints
- 7 Powertrain 6% of all complaints
- 8 Visibility 6% of all complaints
- Structure: 4 complaints (22% of all); manufacturer bulletins for this component: 66.
- Electrical system: 3 complaints (17% of all); manufacturer bulletins for this component: 337.
- Engine: 3 complaints (17% of all); manufacturer bulletins for this component: 45.
- Suspension: 3 complaints (17% of all); manufacturer bulletins for this component: 43.
- Exterior lighting: 2 complaints (11% of all); manufacturer bulletins for this component: 39.
Symptoms owners describe
How many of the 18 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Structure | 4 | 0 | 66 |
| Electrical system | 3 | 0 | 337 |
| Engine | 3 | 0 | 45 |
| Suspension | 3 | 0 | 43 |
| Exterior lighting | 2 | 0 | 39 |
| Air bags | 2 | 0 | 8 |
| Powertrain | 1 | 0 | 111 |
| Visibility | 1 | 0 | 58 |
| Steering | 1 | 0 | 48 |
| Service brakes | 1 | 0 | 14 |
| Lane departure | 1 | 0 | 7 |
| Tires | 1 | 0 | 1 |
| Communication | 1 | 0 | 0 |
| Seat belts | 1 | 0 | 0 |
What owners report
Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.
Blind Spot Warning, All electronics. I immediately return the vehicle to the dealership. One of the technicians and the manager acknowledged that not only do they see it because itâs still current, but theyâve had similar issues before. They would attempt to repair it with some software updates.
Blackout screen while driving. Mileage incorrectly reading. Speed limit incorrectly reading while driving the Dashboard pick up the undercarriage camera. The electricity on the car keep popping up. I have been complaining over 1yr since I lease the vehicle they only offer to trade with me paying the expenses.
2018 Mercedes C300 - a hole rusted through the rear subframe causing structural safety concerns. This car has been routinely washed weekly and the frame should not have rusted through within only 8 years. This also led to a large repair bill.
The Check Engine warning light has illuminated numurous times, resulting 4 separate towing incidents. Despite multiple warranty repairs, the same issues keep recurring. At only 10,167 miles, one tire required replacement due to abnormal wear.
Defect 1 â Recurring Strut Assembly: Following an AC sensor replacement on February 11, 2026, a loud rattling noise emerged from the dashboard/strut area. The vehicle was retained 22 days without resolution. The strut plate was repaired, but the noise recurred.
This has caused my sunroof to malfunction, and it won't close now. I garage my car and barely drive it. I bought it used in Dec. 2021. There was about 46,000 on it in Dec 2021 and now (June 2026) the mileage is 51,000. Yes, the car is available for inspection. 2) I was on the freeway, didn't see it come off.
When owners complained
NHTSA complaints by filing year. The peak shows at what age the problems show up most.
What to check before buying
- Structure. Rails, pillars, panel gaps, signs of pulling or welding.
- Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
- Engine. Cold start, unusual noises, oil leaks and engine codes.
- Suspension. Wheel alignment, control arms, subframe, even tire wear.
Manufacturer service bulletins
Bulletin titles as filed with NHTSA.
- A software update will be performed that provides enhancements to the robustness and system stability of…
- Complaint Clanking noise from the area of the speakers in the doors
- Complaint Slight creaking noises when steering
- Complaint Customer complaints relating to automatic transmission 725.0 (NAG3 Classic /9G‑TRONIC automatic…
- Complaint Repeat workshop visit for vehicle vibration while braking from 60MPH. NOTE
- Complaint Issue after OTA Update IC Odometer Reading blank("_ _ _ _") IC Maintanence data unavailable…
- Complaint Radio station cover art does not refresh when switching stations
- Complaint Only vehicles with a variable transfer case are affected
- Complaint Whining / humming noises (described as foghorn‑like) from the drivetrain in the rear axle area…
- Complaint Traffic sign symbol for "Traffic Sign Assist" is blinking in instrument cluster without obvious…
- Complaint Customer complaints relating to automatic transmission 725.0 (NAG3 Classic / 9G‑TRONIC automatic…
- Complaint The Apple Music app is no longer available in the head unit apps menu after updating the…
Other models of this make
Read also
Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-05.