To perform diagnostics on GM vehicles using CAN interface, you need the Tech 2 and a CAN diagnostic interface module (CANdi Module). The CANdi module connects between the Tech 2’s diagnostic link cable and the OBD adapter. Once the CANdi module is connected, it can be used on all GM vehicle applications, even those vehicles using other platforms such as OBD I and OBD II (CANdi Module is included in the Tech 2 Deluxe Kit 3649).
CAN diagnostic interface module and instruction sheet.
Important: for the CANdi module to work, you must have a 32 MB PCMCIA card with at least software version 24.001 in your Tech 2 Flash.