Mercedes-Benz CL550 2011–2020 — technical service bulletin

Bulletin ELW - M278 Cat · NHTSA communication 10240203 · issued Jul 27, 2023

Technical service bulletin

communication type

Engine and Engine Cooling

component

2011–2020

model years

vehicle entries

Official summary

This NCU replaces the prior NCU issued on May 11, 2023, and clarifies replacement part information. In our continuing efforts to assure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz AG (â MBAGâ ), the manufacturer of Mercedes-Benz vehicles, is extending the warranty coverage on the catalytic converter system in certain Model Year (â MYâ ) vehicles fitted with the M278 8-cylinder engine listed below: - MY2011: Original New Vehicle Limited Warranty of 4 years / 50,000 miles New Vehicle to 13 years / 156,000 miles (whichever occur

Vehicles covered

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.