AI Damage2026 Mercedes-Benz C 300 4matic: common problems
Owners of the 2026 Mercedes-Benz C 300 4matic filed 1 complaints with NHTSA, most often about electrical system and exterior lighting. The maker issued 88 service bulletins for this year. Details by component below, with sources.
Key figures
- Owner complaints
- 1
- Technical service bulletins (TSB)
- 88
What fails most often
- 1 Electrical system 100% of all complaints
- 2 Exterior lighting 100% of all complaints
- 3 Vehicle speed control 100% of all complaints
- Electrical system: 1 complaints (100% of all); manufacturer bulletins for this component: 48.
- Exterior lighting: 1 complaints (100% of all); manufacturer bulletins for this component: 5.
- Vehicle speed control: 1 complaints (100% of all).
Components owners complain about
| Component | Owner complaints | involving a crash | Technical service bulletins (TSB) |
|---|---|---|---|
| Electrical system | 1 | 0 | 48 |
| Exterior lighting | 1 | 0 | 5 |
| Vehicle speed control | 1 | 0 | 0 |
| Structure | 0 | 0 | 9 |
| Steering | 0 | 0 | 8 |
| Visibility | 0 | 0 | 8 |
| Suspension | 0 | 0 | 7 |
| Powertrain | 0 | 0 | 5 |
| Seats | 0 | 0 | 4 |
| Backover prevention | 0 | 0 | 2 |
| Service brakes | 0 | 0 | 2 |
| Air bags | 0 | 0 | 1 |
| Engine | 0 | 0 | 1 |
| Fuel/propulsion system | 0 | 0 | 1 |
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.
Comparison
By complaint count this model year ranks 24,720 of 36,656 model years in the NHTSA data (among the 33% least complained about).
On average one model year of the C 300 4matic has 2 complaints (8 years in the data). This year has 1, below average.
What to check before buying
- Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
- Exterior lighting. Headlamps, leveling, sensors and mounts after a frontal hit.
- Vehicle speed control. Accelerator pedal, cruise control, throttle codes.
- Structure. Rails, pillars, panel gaps, signs of pulling or welding.
Manufacturer service bulletins
Bulletin titles as filed with NHTSA.
- Complaint Clanking noise from the area of the speakers in the doors
Cause Under analysis. Remedy To narrow down the cause, first of all remove the door trim. • If the noise continues to occur even with the door trim removed, then continue the diagnosis working towards the speaker and…
- Complaint Slight creaking noises when steering
Cause Noises may come from one or more sleeves of the horn contact plate. Remedy Remove the horn contact plate and check the sleeves for noise; see attached video. If necessary, apply lubricant to the sleeves.
- Complaint Repeat workshop visit for vehicle vibration while braking from 60MPH. NOTE
Although the symptom is similar to a tire or wheel vibration, it is usually readily noticeable that it is distinctly different if it happens at all times or only while braking. Cause Although the cause of the vibration…
- Complaint Issue after OTA Update IC Odometer Reading blank("_ _ _ _") IC Maintanence data unavailable…
Complaint Issue after OTA Update IC Odometer Reading blank("_ _ _ _") IC Maintanence data unavailable Cause OTA Update E61.0 Remedy In the IC Control Unit Log, please check the following information: Verify whether…
- Complaint Radio station cover art does not refresh when switching stations
The UI continues to show the old station’s artwork instead of updating to the new one. Cause When a new station change request is triggered, a temporary glitch is causing the Head Unit application to fail to overwrite…
- Complaint Whining / humming noises (described as foghorn‑like) from the drivetrain in the rear axle area…
Complaint Whining / humming noises (described as foghorn‑like) from the drivetrain in the rear axle area during cornering. (figure 1) On the above‑mentioned vehicles with a mileage up to 15,000 km (about 9,300 mi)…
- Complaint Traffic sign symbol for "Traffic Sign Assist" is blinking in instrument cluster without obvious…
Complaint Traffic sign symbol for "Traffic Sign Assist" is blinking in instrument cluster without obvious cause usually with one of the following scenarios: • Flashing without a speed limit ("‑ ‑"). • Flashing when…
- Complaint The Apple Music app is no longer available in the head unit apps menu after updating the…
Complaint The Apple Music app is no longer available in the head unit apps menu after updating the software of the (A26/17 ‑ MBUX multimedia system + instrument cluster (head unit)) to E333.8 / A236 904 19 00. Cause…
- Complaint CEL illuminates and/or AC does not blow cold
Cause Potentially relevance to hardware and/or software Remedy Scenario 1: 1. If the AC does not blow cold air, replace compressor (if compressor's index and part number Figure 1 match against Table 1). a. If the…
- Dear Dealer Partners, The part numbers listed in the chart below should no longer be installed and any…
Dear Dealer Partners, The part numbers listed in the chart below should no longer be installed and any existing stock must be returned to your facing PDC. The deadline for all dealer returns is Thursday, October 8th…
- Complaint During part of the steering movement, it feels heavier or more difficult to steer in the same…
Complaint During part of the steering movement, it feels heavier or more difficult to steer in the same spot every time. OR Rattling, humming, dry sliding/gravel noise from the electric steering system when steering…
- Complaint Tailgate opens unintentionally
Cause Accidental or unnoticed activation of the button to open the tailgate on the vehicle key. EXAMPLE: when stored in trouser pocket, handbag etc. Remedy As of the 6th generation, the vehicle key can be recoded so…
NHTSA lists 88 bulletins for this year; the 12 newest are shown here.
Other years of this model
Questions and answers
What are the most common problems with the 2026 Mercedes-Benz C 300 4matic?
Owner complaints to NHTSA most often mention: electrical system, exterior lighting, vehicle speed control. Total complaints: 1. The most frequent symptoms in complaint texts: driver assists: adaptive cruise, lane keeping (100%).
How many service bulletins (TSB) were issued for the 2026 Mercedes-Benz C 300 4matic?
NHTSA lists 88 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.
Should I buy a 2026 Mercedes-Benz C 300 4matic from a US auction?
Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.
Other 2026 models
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.