DTC Description
WARNING: This page is about a different car, the 2021 Kia Soul. However, it is still accessible from the selected car via links, so may be relevant.
An open stuck thermostat means an increase of the engine warm up time and can cause emission increase as well. To detect open stuck thermostat, the PCM checks measured coolant temperature as soon as calculated coolant temperature reaches threshold and sets DTC P218100 when measured coolant temperature is lower than threshold. If same code is set again in the next driving cycle, MIL is illuminated.