Home · 2021 Mercedes-benz C-class Phev · Complaints

What 14 owners told NHTSA about the 2021 Mercedes-benz C-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 (14)Engine (7)Fuel system (3)Airbags (2)Transmission & drivetrain (2)Backup camera & sensors (1)Electrical system (1)Suspension (1)Visibility & wipers (1)

3 of 14 complaints match · Fuel system · clear filters

May 19, 2026Fuel system

The contact owns a 2021 Mercedes Benz C. The contact stated that while driving on the highway, the vehicle began to lose power, riding rough. The check engine light illuminated. The vehicle was towed to the dealer where it was diagnosed with a fuel injection failure. The vehicle read diagnostic code P1CEF85. The manufacturer was made aware of the issue. The approximate failure mileage was 60,000.

NHTSA ODI 11738727

Nov 25, 2025Fuel system

My car had a coolant leak last year a hose broke and I have a 2021. My son’s mercedes sis the same thing on 11/23/2025. I have researched ma y others with this same issue. There should be a recall on that hose or whatever the problem Is.

NHTSA ODI 11701496

Oct 6, 2025Fuel system

While driving car on Sunday 10/5, it suddenly failed to respond to gas pedal pressure. The car stopped accelerating and rather slowed to 15 MPH, almost causing a car from behind to hit me in the rear side.

NHTSA ODI 11691568

Working with the data? Download all 14 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 2021 Mercedes-benz C-class Phev verdict →