Mini-vci J2534 Standard Obd2 Communication Interface Driver -

Abstract This paper presents the architecture, protocol mapping, and implementation of a driver for Mini-VCI (Vehicle Communication Interface) hardware that complies with the SAE J2534 Pass-Thru standard. The driver enables universal vehicle diagnostics and reflashing by translating standard J2534 API calls (e.g., PassThruConnect , PassThruReadMsgs , PassThruWriteMsgs ) into proprietary Mini-VCI commands over USB. Experimental results show successful communication with CAN (ISO 15765-4), K-Line (ISO 14230), and PWM/VPW protocols, achieving real-time OBD2 compliance. 1. Introduction Modern vehicle diagnostics rely on standardized interfaces. SAE J2534 defines a pass-thru API allowing aftermarket software (e.g., scan tools, ECU flashing tools) to communicate with vehicle networks using a generic driver. Mini-VCI is a low-cost, widely used hardware interface originally designed for Toyota/Lexus (Techstream), but it supports multiple protocols: CAN, K-Line, J1850 VPW/PWM, and ISO 9141.

PassThruOpen() → Initialize USB VCP handle PassThruConnect() → Set protocol, baud rate, filters PassThruWriteMsgs() → Send OBD2 requests (e.g., 7DF 02 01 00) PassThruReadMsgs() → Receive responses with timestamps PassThruStartPeriodicMsg() / StopPeriodicMsg() PassThruIoctl() → Voltage, baud rate, filters, five-baud init PassThruClose() 4.1 Command Frame Format (Mini-VCI native) | Byte 0 | Byte 1-2 | Byte 3 ... N-1 | Byte N | |--------|----------|----------------|---------| | CMD ID | Length | Payload | Checksum| mini-vci j2534 standard obd2 communication interface driver