2015 Mercedes-Benz S550 problems & reliability
41 owner complaints filed with NHTSA for the 2015 Mercedes-Benz S550, alongside 5 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 |
|---|---|---|
| Seat Belts | 7 | 17% |
| Unknown / Other | 7 | 17% |
| Electrical System | 5 | 12% |
| Structure | 5 | 12% |
| Wheels | 5 | 12% |
| Air Bags | 4 | 10% |
| Steering | 4 | 10% |
| Engine | 3 | 7% |
| Fuel/propulsion System | 2 | 5% |
| Service Brakes | 2 | 5% |
Component groups as classified by NHTSA. A complaint can name more than one component, so shares may sum to more than 100%.
All 20 reported components →Complaints by incident year
What owners report
“I loss my electric steering assist!!! Takes 2 gorillas to turn the wheel i was able to stop without crashing into anything”
Steering · filed Jan 30, 2026
“The contact owns a 2015 Mercedes-Benz S550. The contact stated that while driving approximately 45 MPH and approaching a stop, the vehicle experienced a loss of automotive power. Several unknown warning lights were illuminated. There was an abnormal ticking sound coming from the engine, and the brakes squeaked while…”
Service Brakes, Hydraulic · filed Aug 5, 2025
“The contact owns a 2015 Mercedes-Benz S550. The contact stated that while operating the vehicle, the air bag warning light remained illuminated, with the message "Front Drivers Air Bag Malfunction - Service Required" displayed. The cause of the failure was not yet determined. The manufacturer and local dealer were…”
Air Bags · filed Jun 5, 2025
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Federal defect investigations
- Front Roof Panel Detachment
Preliminary Evaluation PE21001 · opened Jan 8, 2021 · closed Oct 14, 2021 · led to recall 21V197000
Technical service bulletins
135 manufacturer communications (TSBs, service campaigns, warranty extensions) are on file with NHTSA for the 2015 Mercedes-Benz S550. 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 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
Complaint Creaking noise, in irregular sequence when driving slowly in combination with slight steering movements and/or Creaking/crackling noises from the area of the wheel bearing on the front axle when cornering/…
LI33.20-P-078406 · Service Bulletin/Repair Instructions · issued Jul 8, 2026
Complaint Creaking noise, in irregular sequence when driving slowly in combination with slight steering movements and/or Creaking/crackling noises from the area of the wheel bearing on the front axle when cornering/…
LI33.20-P-078406 · Service Bulletin/Repair Instructions · issued Jul 7, 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 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 S550 has 5 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 S550?
- · 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.