WenmarOpen by Wenmar Pro

Service bulletin LI01.00-P-078172

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)
TypeService bulletin
NHTSA id11027596
Published by NHTSA2026-01-13
Manufacturer's numberLI01.00-P-078172
Manufacturer's date2026-01-12
NHTSA componentENGINE

NHTSA's summary

Complaint Dull thumping noise or ticking noise under the vehicle in the area of the engine/two-mass flywheel/transmission. Is significantly perceptible at the front right wheel well and can also be faintly heard in the vehicle interior. Cause The ticking noise occurs in idle operation in drive program C & S at 780 rpm when the state of charge of the battery is over 65% and the load requirement at the belt-driven starter alternator is simultaneously over 25 Nm. The load requirement can occur due to a number of auxiliary consumers (e.g. air conditioning system, steering wheel or seat heating, etc.). Remedy Check the software version on N127 (PTCU) and N15/15 (transmission) and update if an update is available. Software change: Adaptation of the idle speed and thereby reduction of the intensity of the noise. If the problem persists, the cause is design-related and therefore corresponds to the series production configuration. Replacing parts does not remedy the problem. Note: The noise is not caused by damage or a defect. It also has no negative effects over the operating time.

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 AMG C432023 to 2024
MERCEDES-BENZ AMG C43 4MATIC2023 to 2026
MERCEDES-BENZ AMG GLC432024
MERCEDES-BENZ AMG GLC43 4MATIC2024 to 2026
MERCEDES-BENZ AMG GLC43 4MATIC COUPE2024 to 2025
MERCEDES-BENZ AMG SL432023 to 2026
MERCEDES-BENZ GLC43 4MATIC COUPE2026

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