Engine Control Module (ECM) Description and Operation: EEPROM
WARNING: This page is about a different car, the 2020 Chevrolet Bolt EV. However, it is still accessible from the selected car via links, so may be relevant.
The electronically erasable programmable read only memory (EEPROM) is an integral part of the ECM. The EEPROM contains program and calibration information that the ECM needs in order to control engine operation.
Special equipment, as well as the correct program and calibration for the vehicle, are required in order to reprogram the ECM, refer to Control Module References for ECM replacement, programming, and setup.