Home · 2015 Mercedes-benz S-class Phev · Complaints

What 51 owners told NHTSA about the 2015 Mercedes-benz S-class Phev

These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.

All (51)Crash / fire / injury (11)Seat belts (8)Body & structure (6)Electrical system (6)Visibility & wipers (6)Airbags (5)Wheels (5)Brakes (4)Steering (4)Engine (3)Fuel system (3)

4 of 51 complaints match · Brakes · clear filters

Aug 5, 2025Fuel systemBrakes

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 turning. While refueling the vehicle, there was fuel leaking from the vehicle. The contact stated that while driving and attempting to stop, the brake pedal was depressed and felt loose, and the vehicle hesitated while coming to a stop. The vehicle was restarted and taken to a local dealer; however, the cause of the failure was not yet determined. Several local independent mechanics were contacted; however, the vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 152,000.

NHTSA ODI 11678585

Apr 13, 2020Transmission & drivetrainElectrical systemBrakesFire

TL* THE CONTACT OWNS A 2015 MERCEDES-BENZ S550. THE CONTACT STATED WHILE DRIVING 40 MPH, HE STARTED TO SMELL BURNING BRAKE PAD ODOR INSIDE OF THE CAB OF THE VEHICLE. THE CONTACT STATED THE PARK BRAKE MALFUNCTION WARNING MESSAGE WAS ILLUMINATED. THE CONTACT WAS ABLE TO PARK AT A NEAR CAR WASH PARKING LOT AND WHEN EXITING THE VEHICLE, HE SAW SMOKE AND FIRE NEAR THE REAR DRIVER CALIPER. THE CONTACT STATED AN EMPLOYEE FROM THE CAR WASH WAS ABLE TO EXTINGUISH THE FIRE. THE FIRE OR POLICE DEPARTMENT WAS NOT NOTIFIED. THE CONTACT STATED NO ONE WAS INJURED. THE VEHICLE WAS NOT DRIVABLE. THE CONTACT CALLED MERCEDES-BENZ OF TAMPA (4400 N DALE MABRY HWY, TAMPA, FL 33614) AND MADE THEM AWARE OF THE FAILURE. THE VEHICLE WAS NOT DIAGNOSED. THE VEHICLE WAS TOWED TO AN INDEPENDENT MECHANIC AND WAS INFORMED THAT THE REAR END DRIVER SIDE ACTUATOR NEEDED TO BE REPLACED. THE VEHICLE HAS NOT BEEN REPAIRED YET. THE CONTACT ALSO MENTIONED ON MARCH 16 2019, WHILE DRIVING 55 MPH, THE INSTRUMENT PANEL FAILED TO FUNCTION PROPERLY AND ILLUMINATE. THE VEHICLE WAS TAKEN TO DEALER WHERE IT WAS DIAGNOSED THAT THE INSTRUMENT CLUSTER WAS NEEDED TO BE REPLACED. THE VEHICLE WAS REPAIRED. THE MANUFACTURER WAS MADE AWARE OF THIS FAILURE. THE CONTACT ALSO MENTIONED IN DECEMBER 2018, WHILE THE VEHICLE WAS STATION STOPPED AT A STOP LIGHT, AND HE ATTEMPTED TO MAKE A RIGHT TURN THE STEERING WHEEL WAS MAKING AN ABNORMAL NOISE. THE CONTACT WAS ABLE TO TAKE A VIDEO OF THE FAILURE. THE VEHICLE WAS TAKEN TO A DEALER WHERE THEY WERE UNABLE TO DUPLICATE THE FAILURE BUT UPON SEEING THE VIDEO THEY DECIDED TO FURTHER INVESTIGATE. THE DEALER WAS ABLE TO DIAGNOSE THAT WITH THE DRIVE SHAFT BRUSH WAS NEEDING TO BE REPLACED. THE VEHICLE WAS REPAIRED. THE MANUFACTURER WAS NOT MADE AWARE OF THIS FAILURE. THE FAILURE MILEAGE WAS 24,387.

NHTSA ODI 11320997

Mar 28, 2018Electrical systemBrakesCrash

2015 MERCEDES BENZ S-550. CONSUMER WRITES IN REGARDS TO VEHICLE SECURITY SYSTEMS MECHANICAL AND ELECTRICAL FAILURE ACCIDENT. *SMD *TR

NHTSA ODI 10849533

Aug 11, 2016BrakesCrash

STOPPED IN TRAFFIC ON A SLIGHT DOWNGRADE FOR A LONG PERIOD OF TIME. BRAKE PEDAL WAS APPLIED FIRMLY, WHEN THE TRUCK IN FRONT OF ME WOULD RELEASE THE PEDAL SLIGHTLY TO ALLOW THE CAR TO DRIFT FORWARD. AFTER SEVERAL TIMES THERE WERE NO BREAKS AND THE CAR DRIFTED INTO THE TRUCK IN FRONT OF US. HAD CAR BACK TO DEALER 2 TIMES THEY CLAIM THEY CAN'T FIND ANYTHING WRONG WITH IT.

NHTSA ODI 10895046

Working with the data? Download all 51 complaints as CSV · fetched from NHTSA July 20, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2015 Mercedes-benz S-class Phev verdict →