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Service bulletin LI54.10-P-080199

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 id11027656
Published by NHTSA2026-01-14
Manufacturer's numberLI54.10-P-080199
Manufacturer's date2026-01-14
NHTSA componentELECTRICAL SYSTEM

NHTSA's summary

Complaint For the potentially affected vehicles, excessively high aging of the battery was calculated at cold battery temperatures (<10°C) 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 Step 1: Software update of A66 battery module (48 V battery) Step 2: Perform reset routine: 2.1 Read out actual value 056 in A66 control unit (age limit SOH-R) a. If SOH-R <= 125%: Delete fault memory in PTCU control unit (N127) and 48 V battery (A66). Process ended. b. If SOH-R > 125%: Drive for 60 min to add SOH-R value. 2.2 Read out actual value 056 in A66 control unit (age limit SOH-R) a. If SOH-R <= 125%: Delete fault memory in PTCU control unit (N127) and 48 V battery (A66). Process ended. b. If SOH-R > 125%: Park vehicle > 12 hours in the workshop at a warm ambient temperature > 15°C, then drive for 60 min. 2.3 Read out actual value 056 in A66 control unit (age limit SOH-R) a. If SOH-R <= 125%: Delete fault memory in PTCU control unit (N127) and 48 V battery (A66). Process ended. b. If SOH-R > 125%: Create TIPS case

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

Electrical system

Trouble codes named

P0A7F

Vehicles listed
MERCEDES-BENZ AMG C432023 to 2024
MERCEDES-BENZ AMG C43 4MATIC2023 to 2026
MERCEDES-BENZ AMG C63 S E2024
MERCEDES-BENZ AMG C63 S E 4MATIC+2024 to 2025
MERCEDES-BENZ AMG C63 S E PERFORMANCE 4MATIC+2026
MERCEDES-BENZ AMG E53E2023
MERCEDES-BENZ AMG GLC432024
MERCEDES-BENZ AMG GLC43 4MATIC2024 to 2026
MERCEDES-BENZ AMG GLC43 4MATIC COUPE2024 to 2025
MERCEDES-BENZ AMG GLC63 S E2025
MERCEDES-BENZ AMG GLC63 S E 4MATIC+2025 to 2026
MERCEDES-BENZ AMG GLC63 S E 4MATIC+ COUPE2025 to 2026
MERCEDES-BENZ AMG S 63 E 4MATIC+2023 to 2025
MERCEDES-BENZ C 3002022 to 2026
MERCEDES-BENZ C 300 4MATIC2022 to 2026
MERCEDES-BENZ E 3502025 to 2026
MERCEDES-BENZ E 350 4MATIC2024 to 2026
MERCEDES-BENZ E 4502024
MERCEDES-BENZ E 450 4MATIC2024 to 2026
MERCEDES-BENZ E 450 4MATIC ALL-TERRAIN2024 to 2026
MERCEDES-BENZ E53 E 4MATIC+2025
MERCEDES-BENZ E53 E 4MATIC+ ALL-TERRAIN2026
MERCEDES-BENZ GLC 3002023 to 2026
MERCEDES-BENZ GLC 300 4MATIC2023 to 2026
MERCEDES-BENZ GLC 300 4MATIC COUPE2024 to 2026
MERCEDES-BENZ GLC 300 COUPE2024
MERCEDES-BENZ GLC 350 E 4MATIC2025 to 2026
MERCEDES-BENZ GLC43 4MATIC COUPE2026
MERCEDES-BENZ S 5002021
MERCEDES-BENZ S 5002023
MERCEDES-BENZ S 500 4MATIC2022 to 2025
MERCEDES-BENZ S 5802021
MERCEDES-BENZ S 5802023
MERCEDES-BENZ S 580 4MATIC2022 to 2025
MERCEDES-BENZ S 580 E2023
MERCEDES-BENZ S 580 E 4MATIC2023 to 2025
MERCEDES-MAYBACH S 5802021
MERCEDES-MAYBACH S 580 4MATIC2022 to 2025
MERCEDES-MAYBACH S 6802023 to 2024
MERCEDES-MAYBACH S 680 4MATIC2022 to 2023
MERCEDES-MAYBACH S 680 4MATIC2025

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