Thinkdiag2 Bidirectional OBD2 Scanner with CAN-FD

The Thinkdiag2 is a Bluetooth OBD2 dongle that turns a phone or tablet into a full-system scan tool. It plugs into the 16-pin connector under the dash and pairs with the THINKCAR app on iOS or Android, so there is no handheld screen to charge or misplace. Where a $40 code reader stops at the engine controller, this one enumerates every module the vehicle reports: ECM, TCM, ABS, SRS, EPB, TPMS, SAS, A/C and BMS. For transmission work that distinction is the whole point, because a harsh 1-2 shift or a slipping torque converter clutch usually lives in the TCM and never sets a generic P-code you can pull with a basic reader.

Bidirectional control is included, which means you can command a component instead of only watching it. Firing a shift solenoid on the bench harness, cycling the TCC solenoid, or running an active test to confirm a pressure control solenoid actually responds tells you in thirty seconds what a wiring diagram and a meter take an hour to prove. Live data streams line pressure, gear commanded versus gear attained, turbine and output shaft speed, and TFT, so you can watch a shift happen while the truck is on a road test. Fifteen-plus service resets cover the jobs that follow a repair, including oil life, throttle relearn, steering angle, TPMS, EPB retract and battery registration.

Two things set it apart at this price. It supports the CAN-FD protocol, which 2019-and-newer GM vehicles use and most budget scanners cannot read at all without a separate adapter. And it carries FCA AutoAuth, so it gets past the Security Gateway module on 2019-up Chrysler, Dodge, Jeep, Ram, Fiat and Alfa Romeo vehicles instead of being locked out of anything that requires write access. Coverage runs to more than 120 brands, AutoVIN identifies the vehicle without you typing it in, and one year of software updates is included with the tool.