{"nhtsa_id":11027656,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-01-14","date":"2026-01-14","document_id":"LI54.10-P-080199","mfr_campaign":null,"replaces":null,"component":"ELECTRICAL SYSTEM","mfr_system":null,"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","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11027656-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11027656-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11027656","components":[{"id":"electrical","name":"Electrical system","parent":null}],"codes":["P0A7F"],"topics":[],"vehicles":[{"make":"MERCEDES-BENZ","model":"AMG C43","year_from":2023,"year_to":2024,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG C43 4MATIC","year_from":2023,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG C63 S E","year_from":2024,"year_to":2024,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG C63 S E 4MATIC+","year_from":2024,"year_to":2025,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG C63 S E PERFORMANCE 4MATIC+","year_from":2026,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG E53E","year_from":2023,"year_to":2023,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC43","year_from":2024,"year_to":2024,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC43 4MATIC","year_from":2024,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC43 4MATIC COUPE","year_from":2024,"year_to":2025,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC63 S E","year_from":2025,"year_to":2025,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC63 S E 4MATIC+","year_from":2025,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC63 S E 4MATIC+ COUPE","year_from":2025,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG S 63 E 4MATIC+","year_from":2023,"year_to":2025,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"C 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300","year_from":2023,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC 300 4MATIC","year_from":2023,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC 300 4MATIC COUPE","year_from":2024,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC 300 COUPE","year_from":2024,"year_to":2024,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC 350 E 4MATIC","year_from":2025,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC43 4MATIC COUPE","year_from":2026,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"S 500","year_from":2021,"year_to":2021,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"S 500","year_from":2023,"year_to":2023,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"S 500 4MATIC","year_from":2022,"year_to":2025,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"S 580","year_from":2021,"year_to":2021,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"S 580","year_from":2023,"year_to":2023,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"S 580 4MATIC","year_from":2022,"year_to":2025,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"S 580 E","year_from":2023,"year_to":2023,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"S 580 E 4MATIC","year_from":2023,"year_to":2025,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-MAYBACH","model":"S 580","year_from":2021,"year_to":2021,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-MAYBACH","model":"S 580 4MATIC","year_from":2022,"year_to":2025,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-MAYBACH","model":"S 680","year_from":2023,"year_to":2024,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-MAYBACH","model":"S 680 4MATIC","year_from":2022,"year_to":2023,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-MAYBACH","model":"S 680 4MATIC","year_from":2025,"year_to":2025,"match":null,"vehicle_ids":[]}],"as_of":"2026-10-19","note":"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.","attribution":[]}