How do you program a ecu?

Programming an ECU (Electronic Control Unit) typically involves connecting a diagnostic tool or programmer to the vehicle's OBD-II port. Using specialized software, you can upload new firmware or configuration files to the ECU, which may involve tuning parameters for performance or functionality. It's crucial to follow the manufacturer's guidelines and use the correct software version to avoid corrupting the ECU. Always ensure the vehicle's battery is charged and stable during the programming process to prevent interruptions.