You must be logged into the ThinkDiag+ app before losing your connection; logging out while offline will lock all functions.
While it sounds like a dream for DIY mechanics, it comes with specific risks: Cons All Brands Unlocked : Access to 100+ car makes. thinkdiag offline
Advanced features that require real-time server calculations (like online ECU coding or some immobilizer functions) will generally not work without an active internet connection. You must be logged into the ThinkDiag+ app