DTC Set Condition
WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.
KOS incorporates EEPROM (nonvolatile memory), and that EEPROM stores the TPMS, KOS and immobilizer information. When the data in EEPROM is failed, this code is set.