# Service bulletin LI20.10\-P\-074508

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.

- Type: Service bulletin
- NHTSA id: 11024631
- Published by NHTSA: 2025\-10\-30
- Manufacturer's number: LI20.10\-P\-074508
- Manufacturer's date: 2025\-10\-28
- NHTSA component: ENGINE

## NHTSA's 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.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2025/MC-11024631-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2025/MC-11024631-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Engine

## Trouble codes named

P0128

## Vehicles listed

- 2018 MERCEDES\-BENZ C 350 E
- 2016 to 2017 MERCEDES\-BENZ C350E
- 2018 MERCEDES\-BENZ GLC 350 E
- 2020 MERCEDES\-BENZ GLC 350 E
- 2019 MERCEDES\-BENZ GLC350E

JSON: [/v1/bulletins/11024631](/v1/bulletins/11024631)

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