MERCEDES-BENZ

LI20.10-P-074508

2025-10-28 · NHTSA 11024631

A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.

Manufacturer summary

Original wording in English

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.

Repeated filings are grouped only when make, bulletin number, publication date and complete summary agree. Original record numbers are retained. Older publications remain available, and an explicit later version is shown when established. Pre-1994 vehicle associations are separated from default results; an unspecified year does not mean all model years apply.