WenmarOpen by Wenmar Pro

Service bulletin LI15.40-P-078041

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 id11005340
Published by NHTSA2024-07-30
Manufacturer's numberLI15.40-P-078041
Manufacturer's date2024-07-15
NHTSA componentPOWER TRAIN

NHTSA's summary

Complaint Whistling and/or howling noises in the area of the engine compartment when idling at low rpm. Cause The high-voltage belt-driven starter alternator (HV-BSA) charges the high-voltage battery whenever its state of charge (SOC) is less than 20% and the speed is lower than 15 km/h. The displayed SOC refers to the value shown in the display (AMG Dynamics). When auxiliary consumers such as the air conditioning system are activated and the on-board electrical system load increases, the idling speed is not sufficient for the HV-BSA to provide enough current to the high-voltage battery. As a consequence, the idle speed is increased in stages. The noises may vary in intensity and frequency depending on the idle speed and load. This causes the noises mentioned above. Remedy Replacing the HV-BSA will not remedy the issue. Charge the high-voltage battery to 100% SOC before handing it over to the customer.

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

Transmission and driveline

Vehicles listed
MERCEDES-BENZ AMG C63 S E2024
MERCEDES-BENZ S 580 E2023
MERCEDES-BENZ S 580 E 4MATIC2024

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