2018 Mercedes-Benz S 450 Problems
Owner-reported complaints filed with NHTSA, grouped by component
Data refreshed
What this page shows
Everything below is an owner-reported complaint submitted to NHTSA about the 2018 Mercedes-Benz S 450, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Reports by component
Ranked by how many owner reports name each component category
- Brakes228.6%
- Driver assistance228.6%
- Powertrain (other)114.3%
- Seat belts114.3%
- Steering114.3%
Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.
Each component in detail
What the reports in each category say, in the owners' own words
Brakes
Reports naming service brakes, the antilock braking system, brake hoses, master cylinders or the parking brake.
From owner reports, verbatim
The contact owns a 2018 Mercedes-Benz S450. The contact stated while driving at an undisclosed speed, the contact attempted to depress the brake; however, the vehicle failed to decelerate and slow as needed. The contact stated that the brakes failed to work as needed. The contact stated that the “Service Required” message was displayed on the instrument panel. The vehicle was taken to a dealer and was diagnosed with electronic parking brake failure. The manufacture was not notified of the failure. The failure mileage was approximately 40,000.
I’m reporting this safety concern and seeking advisement from those more knowledgeable than myself on this issue. Recently, as I attempted to actuate the brake of my vehicle. My right foot was entangled with the brake pedal as I moved it from the acceleration pedal to the brake pedal in observance of a “Stop Sign.” I barely avoided what surely would have been a catastrophic collision with another vehicle. The incident occurred in a split second. The shoe of my right foot was entangled with the lower right corner of the underside of the brake pedal, which has a protruding sharp thin metal edge. The sharp thin metal edge impeded the performance my right leg as it dug into my shoe’s sole edge and the leather upper. In my opinion the sharp thin metal edge of the underside of the brake pedal as described herein is a dangerous and extremely problematic issue. After the recent incident, I am consumed with concern, trepidation and fear when operating the vehicle. During the excitement of the near collision, my wife made an audible gasp, and in the split second I struggled to free my shoe and foot to avoid a potentially fatal crash. I barely freed my foot and shoe in time enough to successfully bring my vehicle to a halt. My wife and I narrowly averted a life changing, potentially deadly accident.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Driver assistance
Reports naming forward-collision avoidance, lane keeping, back-over prevention, cruise control and related electronic driver-assistance systems.
From owner reports, verbatim
TL* THE CONTACT OWNS A 2018 MERCEDES-BENZ S450. WHILE DRIVING 75 MPH WITH THE CRUISE CONTROL ENGAGED, THE AUTOMATIC BRAKING ACTIVATED ON ITS OWN IN TRAFFIC. THE CONTACT HAD TO DEPRESS THE BRAKE PEDAL TO DISENGAGE THE CRUISE CONTROL IN ORDER TO DRIVE SAFELY. THE VEHICLE WAS TAKEN TO MERCEDES-BENZ OF ALEXANDRIA (200 S PICKETT ST, ALEXANDRIA, VA 22304, (703) 341-2100) TO BE DIAGNOSED, BUT THE FAILURE COULD NOT BE DUPLICATED. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE. THE FAILURE MILEAGE WAS 49,826.
THE PRE-COLLISION SAFETY FEATURE GOES OFF WHEN THERE IS NO COLLISION IMMINENT. IT IS FRIGHTENING AND COULD ACTUALLY CAUSE AN ACCIDENT.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Powertrain (other)
Powertrain reports that are not specifically the engine or transmission — driveshafts, axles, transfer cases and differentials.
From owner reports, verbatim
The contact owns a 2018 Mercedes-Benz S450. The contact stated while driving at an undisclosed speed, the gear shifter independently shifted into neutral. The contact had to hold down the gear shifter for about 30 seconds before the system was reset. Additionally, the check engine warning light was later illuminated. The vehicle was taken to the dealer where it was diagnosed with transmission valve body failure. The contact was informed that the transmission valve body needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and a case was filed. The contact was advised to contact the NHTSA Hotline to report the failure. The failure mileage was approximately 89,000.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Seat belts
Reports naming seat belts, buckles, retractors and pretensioners.
From owner reports, verbatim
THE PRE-COLLISION SAFETY FEATURE GOES OFF WHEN THERE IS NO COLLISION IMMINENT. IT IS FRIGHTENING AND COULD ACTUALLY CAUSE AN ACCIDENT.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Steering
Reports naming the steering system — racks, columns, power-steering assist and steering linkage.
From owner reports, verbatim
Steering wheel became extremely stiff to turn and a message that read “steering malfunction increase physical effort” appeared while driving at around 30 mph while in a vacation trip, not only was this extremely unsettling since it happened suddenly but I had to act fast to avoid a collision with other vehicles, once I made it to a safe location I shut the vehicle off and restarted after 15 minutes and it seem drivable again but left me extremely concerned as I am 500 miles away from with no dealerships open to have it looked since is Memorial Day.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Elsewhere on this vehicle
Data sources
- NHTSA Office of Defects Investigation — owner-reported complaints and the components recorded on them
Data on this page last refreshed .