{"nhtsa_id":11016046,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2025-03-28","date":"2025-03-26","document_id":"LI54.21-P-078926","mfr_campaign":null,"replaces":null,"component":"ELECTRICAL SYSTEM; ENGINE","mfr_system":null,"summary":"Complaint Check engine light comes on when driving/starting the vehicle. No drivability concerns. Cause SW conflict of the 48V battery Remedy 1.-Check for SW in the 48V battery. 1. If SW is available, update the 48V battery. 2. Clear all faults and perform a few drive cycles. 3. If no faults return, the vehicle can be released. 2.-If no SW available, perform the following: - Charge the batteries (<5A charging current) - Erase the fault codes - Access the 12V battery contacts - Ignition off and bus sleep for 10 minutes - Disconnect the 12V battery - Wait 10 minutes - Disconnect Connector 3 at the 48V battery - Disconnect Connector 5 at the DCDC converter - Disconnect the 48V and 12V contacts (40/41 and 30/31) at the DCDC converter - Wait for 10 minutes - Reconnect everything back in opposite order and perform the ISU of the DCDC - Conduct a test drive and after check for fault codes U014687 and U044287","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11016046-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11016046-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11016046","components":[{"id":"electrical","name":"Electrical system","parent":null},{"id":"engine","name":"Engine","parent":null}],"codes":["U0146","U0442"],"topics":[],"vehicles":[{"make":"MERCEDES-BENZ","model":"AMG CLA35","year_from":2020,"year_to":2024,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG CLA45","year_from":2020,"year_to":2024,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLA 35","year_from":2024,"year_to":2025,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLA 45S","year_from":2024,"year_to":2024,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLA35","year_from":2021,"year_to":2023,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLA45","year_from":2021,"year_to":2023,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"CLA 250","year_from":2020,"year_to":2024,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLA 250","year_from":2020,"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":[]}