Mercedes-Benz AMG EQS 2022–2025 — technical service bulletin

Bulletin LI54.10-P-079534 · NHTSA communication 11021802 · issued Aug 8, 2025

Technical service bulletin

communication type

Electrical System

component

2022–2025

model years

vehicle entries

Official summary

Complaint: Red 12 V battery warning message in IC DTC stored in EZS or currently: B161609 No DTC in DC/DC converter DC/DC converter is not providing any output voltage or output current Cause: Due to a reduction in resistance at the HV voltage divider, the DC/DC converter measures an incorrect HV voltage. Regulation of the 12 V output voltage is therefore unstable or turns off. Remedy: Check of the DC/DC converter via XENTRY Diagnosis Actuate BUCK mode for approx. 40 s Normally, the output current will jump up to a high value (e.g. 100 A) and then slowly drop to the current specified value (e.

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.