NHTSA service bulletin

NHTSA Service Bulletin 11031734: 2015-2017 Mercedes-benz S550

Official manufacturer communication context for 2015-2017 Mercedes-benz S550, with affected products, buyer checks and links into Carchieve recall, problem and VIN research.

NHTSA service bulletin 11031734 summary graphic for 2015-2017 Mercedes-benz S550
11031734NHTSA document ID
Warranty program / extensioncommunication type
4affected product rows
90/100quality score

Reviewed June 2026 from NHTSA manufacturer communication and service bulletin records. Carchieve is independent and not affiliated with any vehicle manufacturer or government agency.

Quick answer

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.

What this bulletin may mean before buying

Treat this as service research, not a verdict on one car. Before you buy, compare this communication with official recall campaigns, model-level owner complaint patterns, and the exact vehicle’s VIN-decoded specifications. A bulletin can help you ask a seller or dealer sharper questions about software updates, known repairs, warranty extensions and service history.

Affected products listed in this communication

MakeModelModel yearsBuyer note
Mercedes-benzS5502015-2017Ask for service records and run the exact VIN before purchase.
Mercedes-benzS550 4matic2016, 2017Ask for service records and run the exact VIN before purchase.
Mercedes-benzS550 Hybrid2016Ask for service records and run the exact VIN before purchase.
Mercedes-maybachS5502017Ask for service records and run the exact VIN before purchase.

Buyer checklist

  1. Run the 17-character VIN and confirm the year, make, model, engine and equipment match the listing.
  2. Check recall campaign pages for safety actions that may require dealer repair.
  3. Compare this bulletin with common problem pages for the same model and component area.
  4. Ask the seller or dealer whether the bulletin procedure, update or inspection has already been completed.
  5. Use the used-car buying checklist and get an independent inspection.

Frequently asked questions

What is NHTSA service bulletin 11031734?

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.

Is a service bulletin the same as a recall?

No. A recall is a safety campaign with a required remedy for affected VINs. A service bulletin or manufacturer communication usually describes diagnostic, repair, software, warranty or service information.

How should a used-car buyer use this bulletin?

Use it as a research signal. Compare it with recalls, owner complaints, service records, a VIN report and an independent inspection before buying.

Check the exact VIN before you buy

Model-level pages show public safety patterns. A full VIN report helps confirm the exact vehicle, decoded specs, recall applicability and buyer checks.

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