2015 Mercedes-Benz C300 problems & reliability
380 owner complaints filed with NHTSA for the 2015 Mercedes-Benz C300, alongside 11 safety recall campaigns. Last verified Sep 22, 2026. Complaints are unverified reports submitted by owners to the federal Office of Defects Investigation.
Each complaint is counted once (by NHTSA case number), even when it names several components.
4 complaints report injuries (7 injured).
Most reported problems
| Component | Complaints | Share |
|---|---|---|
| Engine → | 127 | 33% |
| Fuel/propulsion System → | 66 | 17% |
| Unknown / Other | 63 | 17% |
| Structure → | 59 | 16% |
| Electrical System → | 50 | 13% |
| Steering → | 23 | 6% |
| Suspension → | 22 | 6% |
| Power Train → | 20 | 5% |
| Air Bags → | 12 | 3% |
| Visibility → | 10 | 3% |
Component groups as classified by NHTSA. A complaint can name more than one component, so shares may sum to more than 100%.
All 24 reported components →Common symptoms owners describe
Keyword analysis of complaint narratives; one complaint can describe several symptoms.
Mileage when problems occurred
Among the 156 complaints that included a usable odometer reading, the median reported incident mileage was 50,000 miles (middle 50% between 21,000 and 70,000 miles).
Complaints by incident year
What owners report
“The contact owns a 2015 Mercedes-Benz C300. While the contact’s son was driving approximately 20 MPH, the vehicle veered to the left and into the next lane when the brake pedal was depressed. The vehicle was cautiously driven back to the residence and parked. The vehicle was later towed to the local dealer to be…”
Structure · filed Sep 1, 2026
“The contact owns a 2015 Mercedes-Benz C300. The contact stated that while driving at various speeds and depressing the brake pedal, the vehicle fishtailed on several occasions. The vehicle was taken to an independent mechanic, where it was raised on a lift, and the mechanic discovered that the rear subframe was…”
Structure · filed Aug 5, 2026
“The contact owns a 2015 Mercedes-Benz C300. The contact stated that while the vehicle was parked, the contact became aware that the panoramic roof failed to close as intended. The vehicle was taken to the dealer, where it was determined that the panoramic roof guide rails had failed. The contact was informed that the…”
Visibility · filed Jul 30, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Federal defect investigations
- C300 Wrist-pin allegation
Defect Petition DP22002 · opened Sep 12, 2022 · closed Feb 27, 2024
- Desiccated Air Bag Inflator Rupture
Engineering Analysis EA21002 · opened Sep 17, 2021 · open
- Front Roof Panel Detachment
Preliminary Evaluation PE21001 · opened Jan 8, 2021 · closed Oct 14, 2021 · led to recall 21V197000
Technical service bulletins
134 manufacturer communications (TSBs, service campaigns, warranty extensions) are on file with NHTSA for the 2015 Mercedes-Benz C300. The 10 most recent:
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…
LI46.35-P-067339 · Service Bulletin/Repair Instructions · issued Aug 28, 2026
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…
LI72.20-P-075746 · Service Bulletin/Repair Instructions · issued Aug 24, 2026
Complaint 1. General Diagnostic Tips 2. One or More PARK Sensor Activations 3. Red Ring Around Vehicle 4. "Active Parking and Parking Assist Inoperative" on Instrument Cluster 5. Cameras 6. Other Park Topics. Cause…
LI54.65-P-080132 · Service Bulletin/Repair Instructions · issued Aug 12, 2026
Complaint A popup is seen on the HU with the message "data connection temporarily not available". Potentially affected functionalities in NTG4.5, NTG5 1.Weather 2.Local Search 3.IP Radio 4.Send2Car 5.Speech Detection…
LI82.85-P-079087 · Service Bulletin/Repair Instructions · issued Aug 6, 2026
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…
LI82.62-P-078631 · Service Bulletin/Repair Instructions · issued Aug 6, 2026
Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The noise is heard once in each instance when changing direction of travel. Note: Sound file in attachment Cause…
LI35.30-P-058566 · Service Bulletin/Repair Instructions · issued Jul 14, 2026
Dear Mercedes-Benz USA Dealers, 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 no later than…
PSL-NCU Return Parts 6/19 · Other · issued Jun 19, 2026
Complaint Service code B1 displayed in the customer menu does not match the workshop code displayed in the workshop menu, e.g., 505 or 550A, which includes a service A. Cause The root cause is currently being…
LI00.20-P-080703 · Service Bulletin/Repair Instructions · issued Jun 12, 2026
Complaint After successful commissioning of the HERMES control unit (N112/9) with XENTRY Diagnosis DVD 03/2026, the message "SOS - service not activated" appears on the instrument cluster. In addition, the following two…
LI82.85-P-080507 · Service Bulletin/Repair Instructions · issued May 26, 2026
Complaint The customer requests deactivation of the N112/9 HERMES communication module Note: Deactivation of the HERMES control unit (N112/9) is not supported for gray-market vehicles. Cause Before deactivating the…
LI82.85-P-080559 · Service Bulletin/Repair Instructions · issued May 26, 2026
TSBs are repair guidance manufacturers send to dealers — they are not recalls and repairs are not automatically free. Full documents are available on NHTSA’s site.
Safety recalls
The 2015 Mercedes-Benz C300 has 11 NHTSA recall campaigns — recall repairs are free at franchised dealers regardless of the vehicle’s age.
Check whether your specific vehicle is affected
Recall campaigns often cover only certain VIN ranges. Enter your VIN on the official NHTSA site to confirm whether your vehicle is included and whether the repair is still open.
Check VIN on NHTSA →Buying a used 2015 Mercedes-Benz C300?
- · Decode the seller’s VIN with our free VIN decoder to confirm the exact year, engine and trim.
- · Check for unrepaired recalls by VIN on NHTSA’s official lookup — recall repairs are free.
- · Among complaints with usable mileage, the median reported incident mileage was 50,000 miles. This does not predict when a particular vehicle will develop a problem.