Mercedes-Benz C 300 2018–2023 — technical service bulletin

Bulletin CL - EW M264 · NHTSA communication 11028003 · issued Jan 23, 2026

Technical service bulletin

communication type

Engine

component

2018–2023

model years

vehicle entries

Official summary

Dear Mercedes-Benz Owner: In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA is extending the warranty coverage on the exhaust valve system in your vehicle from the original New Vehicle Limited Warranty of 4 years/ 50,000 miles to 15 years/ 150,000 miles (whichever occurs first). This applies to the vehicle regardless of ownership. On certain Model Year 2018 - 2023 C-Class, E-Class, GLC and GLE vehicles with the 4-cylinder engine "M264", over time, the exhaust valve system might not continue t

What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.

Mercedes-Benz C 300 2018–2023 — technical service bulletin

Official summary

Vehicles covered