Home · 2011 Mercedes-benz S-class Phev · Complaints

What 18 owners told NHTSA about the 2011 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 (18)Crash / fire / injury (3)Fuel system (6)Electrical system (4)Engine (4)Suspension (2)Body & structure (1)Brakes (1)Hybrid Propulsion System (1)Speed control (1)Wheels (1)

1 of 18 complaints match · Speed control · clear filters

Oct 7, 2016Electrical systemSpeed control

TL* THE CONTACT OWNS A 2011 MERCEDES-BENZ S550. WHILE DRIVING 70 MPH, THE VEHICLE ACCELERATED UP TO 110 MPH ON ITS OWN. THE REAR OF THE VEHICLE RATTLED WITHOUT WARNING. ON ANOTHER OCCASION, ALL THE WARNING INDICATORS FAILED TO ILLUMINATE AND THE GPS PROVIDED INCORRECT INFORMATION. THE VEHICLE WAS TAKEN TO A DEALER, BUT THEY COULD NOT DUPLICATE THE FAILURE. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE. THE FAILURE MILEAGE WAS UNKNOWN.

NHTSA ODI 10914797

Working with the data? Download all 18 complaints as CSV · fetched from NHTSA July 21, 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 2011 Mercedes-benz S-class Phev verdict →