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Other CL- Engine Coolant

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeOther
NHTSA id11031734
Published by NHTSA2026-04-30
Manufacturer's numberCL- Engine Coolant
Manufacturer's date2020-02-21
NHTSA componentENGINE

NHTSA's summary

The purpose of this letter is to advise you of additional benefits that Mercedes-Benz USA, LLC ("MBUSA") is providing to you regarding your vehicle ownership. What's Included In our continuing efforts to assure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, MBUSA is extending the warranty to a total of 10 years and 120,000 miles from the vehicle's original New Vehicle Limited Warranty start date for coolant system repairs that may be needed arising from an illumination of a Malfunction Indicator Lamp ("MIL") due to engine coolant backflow in the affected vehicles. This warranty extension addendum applies to the vehicle regardless of ownership. Under this warranty extension, subject vehicles will be retrofitted with an engine coolant system check-valve to resolve faults related to engine coolant backflow. This warranty extension is applicable to the following vehicles: Any repairs under this warranty extension must be performed by an authorized Mercedes-Benz dealership. This extended warranty does not apply to any other engine or electrical components beyond the ones expressly mentioned above, and standard warranty terms apply, including the exclusions with respect to extra expenses, as identified in the Service and Warranty Information booklet. In case of failure of any other engine or electrical system component other than the aforementioned part that is beyond the vehicle's original New Vehicle Limited Warranty of 4 years/50,000 miles, the associated repair will not be covered and will remain the owner's responsibility.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Engine

Vehicles listed
MERCEDES-BENZ S5502015 to 2017
MERCEDES-BENZ S550 4MATIC2016 to 2017
MERCEDES-BENZ S550 HYBRID2016
MERCEDES-MAYBACH S5502017

Listing a model year does not mean every vehicle of it is concerned: the document says which.