SMK & PM (ECM/TCM) Control Module (ECM Memory Error)
WARNING: This page is about a different car, the 2020 Hyundai Kona. However, it is still accessible from the selected car via links, so may be relevant.
Information regarding an Immobilizer is stored in two separate areas of the EEPROM inside the ECM. The ECM checks both types of the information before the Immobilizer Authentication process. When the ECM confirms that they correspond, the Immobilizer Authentication begins. If they do not, the ECM stops the authentication and store the "ECM Memory Error" DTC. When this occurs, the Limp Home function cannot be performed. If the problem persists after registering a new key, the ECM must be replaced.