HomeLI20.10-P-072886 · MERCEDES-BENZ, MERCEDES-MAYBACH
MERCEDES-BENZ, MERCEDES-MAYBACH

LI20.10-P-072886

Manufacturer communications

Publication date
2026-07-24
Received by NHTSA
2026-07-27
NHTSA record numbers
11035234

Manufacturer summary

Original wording in English

Complaint Check Engine Light ON with DTC P012800 "The Coolant Temperature is Below the Specified Temperature" active and/or stored in the ME (N3/10). There are no drivability concerns related to this complaint. Cause Root cause varies Remedy Prior to performing any repairs for this complaint: With a cold engine, pressurize the high temp coolant circuit and while it's under pressure, release the cap on the low temp coolant circuit and check if the pressure drops right away or not. If the pressure drops, the lower coolant hoses are swapped. Correct this, fill, bleed and test drive the vehicle. If the complaint returns, then continue with the steps below. IMPORTANT: Use VMI to check for the following emission extended warranty –> Engine Thermostat (incl. software update) MY19-23, Various Models and Platforms (167, 190, 205, 213, 217, 222, 223, 232, 253, 290, 463) If the vehicle is covered under the above emission extended warranty, please perform steps outlined in the accompanying NCU prior to those outlined in this document. If vehicle is not covered under the above emission extended warranty or the complaint continues to occur, then proceed as follows: Check for available software updates to the ME (N3/10). If updated software is available, perform the update, clear the DTC and the perform each of the "WARM START" and "COLD START" test drives listed below twice. If the code does not re-appear then release the vehicle. If there is no new software available OR the DTC returns after the test drives then perform the following steps:
• Drain the coolant through a fine mesh sieve and check for signs of debris. Additionally, inspect the coolant reservoir for debris. If any debris is found take pictures of the reservoir and the mesh filter and "flush" the system at least 2-3 times to clear as much of the debris as possible
• Replace the thermostat and bleed the system as outlined in AR20.00-P-1142-04A, evacuate the system for 20-30 minutes instead of the 5 minutes specified in step 22
• NOTE: Please use all the tools specified in the AR document. The DTC will continue to populate if the circuit is not properly bled
• NOTE: There are two valid thermostats to choose from in the parts section of this LI. Please verify which PN is applicable for the vehicle being worked on via XENTRY Parts Information
• After bleeding the system clear the DTC and perform each of the "WARM START" and "COLD START" test drives listed below twice. If the DTC does not reappear after the tests, release the vehicle If the ME (N3/10) software is up to date, the thermostat has already been replaced, and the complaint persists open a TIPS case and attach the following documents:
• Initial quick test
• ME (N3/10) control unit log
• The results of an R48 test from a “yes” response and from a “no” response
• Pictures of the coolant reservoir and mesh sieve (mentioned above) WARM START · Begin with the engine coolant temperature at approximately 50 degrees C · Activate the AC system, if defrost is not in use open the windows · Drive the car normally until a coolant temperature of 75 degrees C is achieved · Depress the accelerator pedal 50% for ~5 seconds (partial acceleration) · Let off the accelerator pedal and let the car coast for ~10 seconds · Continue to drive the car normally COLD START · Drive for ~7 miles (normal driving) · Shut off the engine in a parking lot (or similar), wait 30 seconds, then restart and continue driving · Depress the accelerator pedal 50% for ~5 seconds (partial acceleration) · Let off the accelerator pedal and let the car coast for ~10 seconds · Continue to drive the car normally

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

MakeModelModel year
Mercedes-BenzAMG C632021
Mercedes-BenzAMG C632020
Mercedes-BenzAMG C632019
Mercedes-BenzAMG C632018
Mercedes-BenzAMG C632017
Mercedes-BenzAMG C632016
Mercedes-BenzAMG C632015
Mercedes-BenzAMG C63 S2023
Mercedes-BenzAMG C63 S2022
Mercedes-BenzAMG C63 S2021
Mercedes-BenzAMG C63 S2020
Mercedes-BenzAMG C63 S2019
Mercedes-BenzAMG C63S2018
Mercedes-BenzAMG C63S2016
Mercedes-BenzAMG C63S2015
Mercedes-BenzAMG E632018
Mercedes-BenzAMG E63 S2023
Mercedes-BenzAMG E63S2022
Mercedes-BenzAMG E63S2021
Mercedes-BenzAMG E63S2020
Mercedes-BenzAMG E63S2019
Mercedes-BenzAMG E63S2018
Mercedes-BenzAMG G632024
Mercedes-BenzAMG G632023
Mercedes-BenzAMG G632022
Mercedes-BenzAMG G632021
Mercedes-BenzAMG G632020
Mercedes-BenzAMG G632019
Mercedes-BenzAMG GLC632022
Mercedes-BenzAMG GLC632021

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