Mercedes-Benz A-Class A180 W176
Arrived with check engine light on.
Quickly read out the fault memory with the diagnostic machine.
"P012800 Water temperature is below the thermostat reference temperature"
Thermostat "opening" error confirmed.
This indicates a malfunction where coolant is flowing to the radiator side more than necessary.
Make sure the engine has cooled down before removing it.
The thermostat is located under the intake manifold.
It won't work unless you remove quite a few auxiliary devices.
I removed the intake manifold and found the thermostat.
The thermos has come off. The one on the right is a new genuine product.
The seals on the removed parts will also be replaced with new ones.
I checked visually and with a bar, but no fixation was found when the thermo valve was in the "open" position.
There is a high possibility that the valve does not move properly in relation to the control or does not close completely.
Assemble the removed parts, replenish coolant, bleed air, and clean.
The fault memory has also disappeared, and there are no abnormalities in the thermostat, water temperature, and fan control data.
After the road test, we conducted a leak test and the repair was completed without any leaks!
"The check engine light came on once, but it hasn't come on since."
"The check light came on, but I don't feel anything is wrong."
Even in such cases, fault memory may remain in the vehicle.
Even the slightest warning sign can help you avoid the worst situations, such as being unable to drive or being towed.
Please contact us as soon as possible after the check light turns on!