{"nhtsa_id":11025541,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2025-11-14","date":"2025-11-11","document_id":"LI54.10-P-080004","mfr_campaign":null,"replaces":null,"component":"ELECTRICAL SYSTEM","mfr_system":null,"summary":"Complaint • Vehicle cannot be started • Warning in the instrument cluster related to High-voltage on board electrical system • The following fault codes related to interlock can be found in the High Voltage Control units : • PTCU (N127) : P154700 - There is a warning due to a detected fault in the interlock circuit. • BMS (N82/9) : P0A0B00 - The interlock circuit of the high-voltage on-board electrical system has a malfunction. P0A0D00 - The interlock circuit of the high-voltage on-board electrical system has a short circuit to positive. • DCB (N116/5): P0A0A00 - The interlock circuit of the high-voltage on-board electrical system has an electrical fault. P0A0B00 - The interlock circuit of the high-voltage on-board electrical system has a malfunction. P0A0C00 - The interlock circuit of the high-voltage on-board electrical system has a short circuit to ground. • OBL (N83/11) : P0A0B00 - The interlock circuit of the high-voltage on-board electrical system has a malfunction. P0A0C00 - The interlock circuit of the high-voltage on-board electrical system has a short circuit to ground. Cause • Oxidation in interlock circuit pins of the low voltage connectors in the components • Twisted harness • Harness scratching with the body • Wiring harness chafed/cut at the ECUs • Broken interlock connector • Improperly connected HV connectors • Interlock pins on HV components are bent or deformed Important Note : • In case of interlock failures, the High-voltage component is less likely to cause the issue. Remedy Remedy 1: Interlock loop resistance measurement (Refer attachment \"243 Interlock Resistance Measurements.pdf\") Remedy 2: Additional check points for interlock issues","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11025541-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11025541-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11025541","components":[{"id":"electrical","name":"Electrical system","parent":null}],"codes":["P0A0A","P0A0B","P0A0C","P0A0D","P1547"],"topics":[],"vehicles":[{"make":"MERCEDES-BENZ","model":"EQB 250+","year_from":2023,"year_to":2025,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"EQB 300 4MATIC","year_from":2022,"year_to":2025,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"EQB 350 4MATIC","year_from":2022,"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":[]}