Background and purpose The jdiag M100 Pro connects to a vehicle’s OBD2 port and communicates via Bluetooth or Wi‑Fi with a smartphone, tablet, or PC. The device itself is a hardware interface; the software provides the user interface, interprets vehicle data, and enables diagnostics. Because vehicle protocols and manufacturer implementations vary, using the official or a reputable third‑party app ensures compatibility, accurate readings, and safer operations when interacting with vehicle modules.