PROM - Programmable Read Only Memory: Application and ID
EEPROM
The electronically erasable programmable read only memory (EEPROM) is a permanent memory that is physically part of the engine control module (ECM). The EEPROM contains program and calibration information that the ECM needs in order to control the powertrain operation.
Special equipment, as well as the correct program and calibration for the vehicle, are required in order to reprogram the ECM.