How is software integration testing performed for automotive ECUs?

ECU software integration testing verifies correct interaction between software components and with hardware. Methods include: Hardware-in-the-Loop (HIL) testing simulating vehicle systems, Software-in-the-Loop (SIL) for early algorithm verification, component integration tests validating module interfaces, network integration testing ECU communication, and system integration testing complete vehicle functionality. Test automation using frameworks like CANoe, dSPACE enables regression testing. Requirements traceability ensures coverage; fault injection validates error handling. Integration testing follows V-model development, occurring after unit testing and before vehicle-level validation.