LI20.10-P-074508

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.