Most ECUs (Bosch, Delphi) use big-endian for checksums. Intel/Motorola MCUs may differ. Always verify against an original unmodified binary. 6.3 Debugging Use OutputDebugString() from Windows API and monitor with DebugView to trace execution without crashing WinOLS.
#ifdef __cplusplus
// Byte swap for little-endian ECU return (crc >> 8) Winols Checksum Dll
uint16_t custom_crc16(const uint8_t* data, uint32_t len, uint16_t init) uint16_t crc = init; for (uint32_t i = 0; i < len; i++) crc ^= (data[i] << 8); for (int bit = 0; bit < 8; bit++) if (crc & 0x8000) crc = (crc << 1) ^ 0x8005; else crc = crc << 1; Most ECUs (Bosch, Delphi) use big-endian for checksums
EXPORTS GetDllVersion GetPluginType CalculateChecksum Most ECUs (Bosch
switch(info->algorithmID) case 1: return crc16_ibm(info); case 2: return checksum_me7_sum8(info); case 3: return custom_renault_checksum(info);