ECU Online Refresh And Remote Service System Development Based On CAN Bus

With the rapid development of automative electronics,new function being innovated.But unfortunately,those new functiongs are hard to be upgraded efficiently to the ECU.Usually,automotive electronics service are carried out mainly in 4S shops,which can not be timely and with geographical constrains.The design of new Bootloader online refreshing and remote service system provide a new solution for the uprade of ECU and remote service of vehicle.An online refreshing system with secure access mode and forced entry access mode,is designed in strict accordance with the standard ISO 15765 diagnostic service.Online security access mode: 1)Using the security access command to open the diagnostic mode,through the hardware boot reset;2)Using FLASH programming to erase user program area and EEPROM;3)Download the application code packages and check the code.4)Using hardware boot reset to jump to the user program,and complete the upgrade.Forced mode that within 500 ms of power on,the host computer will send mandatory upgrade instructions,and the process after is same as 2)to 4)in security access mode.By strict atribution of the memory address,the Bootloader,the user program and other parts will be all relatively independent.By setting FLASH protection at the high address,so that the upgrading process becomes more stable.The design of "check-in" algorithm improves the stability and efficiency of data receiving.The hardware module of CAN Bluetooth communication is designed by using Altium Designer.The software of the three functional modules,which include Online upgrade,remote monitoring,fault diagnosis,are designed separately according to the functions.Bluetooth serial communication protocol is designed.By completing the handshake dialogue with the Bootloader,to complete the online refreshing of the ECU;By setting the ID list and forwarding cycle time,the bus data are forwarded through the remote service application,Real-time transmission of ECU data to the remote service terminal,monitoring of the engine can be realized;By monitoring the vehicle system fault code,dynamic display of current fault information.The final test results show that the online refreshing system has the advantages of campatibility,high efficiency and reliability.The test result shows that it can overcome the power-down problem encountered during the upgrade process.CAN Bluetooth communication module combined with the new Bootloader can upgrade the ECU program remotely.The CAN Bluetooth communication module can also be connected with the server terminal for remote data monitoring,real-time display of the current operating status of OBD system.