MERCEDES-BENZ, MERCEDES-MAYBACH

LI54.10-P-077250

2025-01-29 · NHTSA 11013190

A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.

Manufacturer summary

Original wording in English

Complaint For the potentially affected vehicles, excessively high aging of the battery was calculated at cold battery temperatures (<50°F) and the MIL activated accordingly, even though there is no corresponding high level of aging physically. In this regard, the fault code P0A7F00 "The age limit of the hybrid/high-voltage battery module has been reached" is displayed in the N127 PTCU control unit and/or A66 battery module control unit (48 V battery). Cause Faulty computation of the age limit of the 48 V battery. Remedy Do not replace any parts!! Step 1: Perform the software update of A66 battery module (48 V battery) After SW has been updated, perform the following reset procedure: Step 1: Read the State of Health Resistance - (SOH-R) Step 2: If SOH-R <=125%: Clear fault memory in PTCU(N127) and 48V battery (A66). Procedure finished. If SOH > 125%: Drive for a duration of 60 minutes to retrain the SOH-R value. Step 3: Read the State of Health Resistance - (SOH-R) If SOH-R <=125%: Clear fault memory in PTCU(N127) and 48V battery (A66). Procedure finished. If SOH > 125%: Park vehicle in Workshop for >12 hours in warm ambient temperature >60F, afterwards drive for a duration of 60 minutes. Step 4: Read the State of Health Resistance - (SOH-R) If SOH-R <=125%: Clear fault memory in PTCU(N127) and 48V battery (A66). Procedure finished. If SOH-R is still >125%, open a TIPS case.

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