AI DamageMercedes-Benz C450: problems, complaints, bulletins
Summary for the Mercedes-Benz C450 across 2 model years: 19 owner complaints and 123 NHTSA service bulletins, plus repair videos. Pick a year for details.
Model years
What fails most often
- 1 Wheels 32% of all complaints
- 2 Electrical system 21% of all complaints
- 3 Structure 21% of all complaints
- 4 Visibility 11% of all complaints
- 5 Steering 11% of all complaints
- 6 Powertrain 5% of all complaints
- Wheels: 6 complaints (32% of all); manufacturer bulletins for this component: 4.
- Electrical system: 4 complaints (21% of all); manufacturer bulletins for this component: 79.
- Structure: 4 complaints (21% of all); manufacturer bulletins for this component: 22.
- Visibility: 2 complaints (11% of all); manufacturer bulletins for this component: 18.
- Steering: 2 complaints (11% of all); manufacturer bulletins for this component: 8.
Symptoms owners describe
How many of the 19 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) |
|---|---|---|---|
| Wheels | 6 | 0 | 4 |
| Electrical system | 4 | 0 | 79 |
| Structure | 4 | 0 | 22 |
| Visibility | 2 | 0 | 18 |
| Steering | 2 | 0 | 8 |
| Powertrain | 1 | 0 | 48 |
| Equipment | 0 | 0 | 37 |
| Exterior lighting | 0 | 0 | 28 |
| Engine and cooling | 0 | 0 | 12 |
| Backover prevention | 0 | 0 | 5 |
| Suspension | 0 | 0 | 5 |
| Engine | 0 | 0 | 4 |
| Fuel/propulsion system | 0 | 0 | 4 |
| Service brakes | 0 | 0 | 4 |
What owners report
Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.
Sudden fracture of the propeller shaft universal joint at freeway speeds causing catastrophic damage to the transmission and exhaust system. This matches the failure described in NHTSA Recall 26V216. While driving on Arizona Freeway 202. Extreme clanking noise heard and lost all power in middle of rush hour.
Just purchased this vehicle in Utah, was driving from Utah to Idaho on the interstate at 80mph when all of a sudden my sunroof opened up with high winds and blew right off. Luckily nobody was behind me but Iâve been driving 2 hours without a sunroof due to weak glue/manufacturing defect
The sunroof locked open during a road trip. I am mechanically inclined, so adding lubricant and driving through a low pressure air front caused the sunroof to shut.
- windshield, and I had Satellite repair it through an insurance claim because it was urgent for my safety. - the windshield and its adhesive never bonded together making the windshield structurally unsafe and if I would have gotten into an accident then my vehicles airbags would have not deployed properly.
Panoramic sunroof pillars/rails detaching while operating vehicle. The front roof panel located between the windshield and the panoramic sunroof may not have been bonded correctly to the vehicle during a prior repair. When operating the vehicle at a moderate speed, the sunroof continued to adjust itself on its own.
The panoramic sunroof does not properly seal to car, allowing the glass to detach and fall from the vehicle during operation and likely to impair the operator during use. Furthermore, without properly sealing the internal cabin is exposed to the environment (i.e.
When owners complained
NHTSA complaints by filing year. The peak shows at what age the problems show up most.
What to check before buying
- Wheels. Wheel runout, cracks, signs of a wheel strike.
- Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
- Structure. Rails, pillars, panel gaps, signs of pulling or welding.
- Visibility. Wipers, mirrors, defrosters, cracked glass.
Manufacturer service bulletins
Bulletin titles as filed with NHTSA.
- Complaint Clanking noise from the area of the speakers in the doors
- 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 Only vehicles with a variable transfer case are affected
- Complaint Customer complaints relating to automatic transmission 725.0 (NAG3 Classic / 9G‑TRONIC automatic…
- Complaint During part of the steering movement, it feels heavier or more difficult to steer in the same…
- Complaint Tailgate opens unintentionally
- Complaint A popup is seen on the HU with the message "data connection temporarily not available"
- Complaint Clanking noise from the area of the speakers in the doors
- Complaint This document is intended as a pre-case diagnostic reference for transmission related concerns
- Complaint Mercedes-Benz USA is currently experiencing limited availability of transmission fluid…
- Complaint Crackling and cracking noise from the outer wheel on the front axle when cornering Cause 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.