{"nhtsa_id":11024631,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2025-10-30","date":"2025-10-28","document_id":"LI20.10-P-074508","mfr_campaign":null,"replaces":null,"component":"ENGINE","mfr_system":null,"summary":"Complaint Check engine lamp illuminated. Fault code stored P012800-The coolant temperature is below the coolant thermostat specified temperature. Cause Various possible causes Remedy 1- Update HVAC with latest software 2- Perform guided test for fault P012800 and performed repairs per XENTRY diagnosis. - If thermostat requires replacement flush cooling circuit in both directions with 150L of water. MY 2020 GLC350e 253.953 only 3- Update the software of engine control unit N3/10. New version A2749022102 A2749032506. Note- If the guided test passes no repair should be performed. SW update for remaining hybrid models is in development for ME control unit to resolve this fault.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11024631-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2025/MC-11024631-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11024631","components":[{"id":"engine","name":"Engine","parent":null}],"codes":["P0128"],"topics":[],"vehicles":[{"make":"MERCEDES-BENZ","model":"C 350 E","year_from":2018,"year_to":2018,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"C350E","year_from":2016,"year_to":2017,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC 350 E","year_from":2018,"year_to":2018,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC 350 E","year_from":2020,"year_to":2020,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC350E","year_from":2019,"year_to":2019,"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":[]}