Study of ISO 14229-1 and ISO 15765-3 and implementation in EMS ECU for EEPROM for UDS application

The diagnostic tester is presented here to read out the contents of external EEPROM of an EMS ECU. The tester and the EMS ECU are built with Unified Diagnostic Service (UDS) on Controller Area Network (CAN) as per ISO 14229-1 and ISO 15765-3. When the tester requests the UDS on CAN bus, the ECU invokes the respective routines. The micro-controller of ECU uses Serial Peripheral Interface (SPI) protocol to read out the contents of EEPROM. The ECU stores the contents read from external EEPROM into a buffer and that will be transmitted on CAN bus as response to the tester request. In this paper, the work flow and the algorithms are provided as, how the tester requests the UDS commands on CAN bus and how the EMS ECU interprets this command to get the contents of EEPROM for the tester, as per ISO 14229-1 and ISO 15765-3.